Journal: J Cardiovasc Electrophysiol

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Abstract

Insights on the pulmonary artery-derived ventricular arrhythmia.

Yang Y, Liu Q, Luo X, Liu Z, Zhou S
Pulmonary artery-derived ventricular arrhythmia is gradually being recognized, which in a clinical context is recognized as an arterial ectopic beat. Our study aimed to provide new insights on the epidemiological characteristics, origin site, electrocardiogram (ECG) characteristics, intra-cardiac electrophysiological characteristics and radiofrequency catheter ablation (RFCA) strategies for pulmonary artery-derived ventricular arrhythmia. Patients with a distance between the origin site and the pulmonary valve of > 10 mm have what is known as pulmonary trunk-derived ventricular arrhythmia, while patients with a distance between the origin site and the pulmonary valve of ≤10 mm have what is known as pulmonary sinus cusp-derived ventricular arrhythmia. It is very difficult to differentiate pulmonary artery-derived ventricular arrhythmia from right ventricular outflow tract-derived ventricular arrhythmia on ECGs as both share similar anatomical features, but pulmonary artery-derived ventricular arrhythmia shows obvious intra-cardiac electrophysiological characteristics. Currently, conclusions based on the epidemiological characteristics of pulmonary artery-derived ventricular arrhythmia, relationship between the origin site and the pulmonary valve, electrophysiological characteristics, and RFCA strategies are controversial and still need further study. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 03 Jun 2018; epub ahead of print
Yang Y, Liu Q, Luo X, Liu Z, Zhou S
J Cardiovasc Electrophysiol: 03 Jun 2018; epub ahead of print | PMID: 29864191
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Abstract

Mechanistic subtypes of focal right ventricular tachycardia.

Lerman BB, Cheung JW, Ip JE, Liu CF, Thomas G, Markowitz SM
Idiopathic sustained focal right ventricular tachycardia (VT) is most frequently due to outflow tract (OT) tachycardia. This arrhythmia is recognized by its characteristic ECG pattern and sensitivity to adenosine. However, there are other forms of idiopathic, focal sustained VT that originate in the right ventricle (RV), which are less well appreciated and easily misdiagnosed. This review will identify the characteristic features and electrophysiologic properties of these forms of RV VT, including those originating from the tricuspid annulus, right ventricular papillary muscles and moderator band as well as variants of classic RVOT tachycardia and those due to microreentry in the presence of preclinical disease. Recognition of these subtypes of focal RV tachycardia should facilitate targeted therapy. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 15 Apr 2018; epub ahead of print
Lerman BB, Cheung JW, Ip JE, Liu CF, Thomas G, Markowitz SM
J Cardiovasc Electrophysiol: 15 Apr 2018; epub ahead of print | PMID: 29659078
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Abstract

Atrial fibrillation ablation using cryoballoon technology: Recent advances and practical techniques.

Chen S, Schmidt B, Bordignon S, Bologna F, ... Nagase T, Chun KRJ
Atrial fibrillation (AF) affects 1-2% of the population, and its prevalence is estimated to double in the next 50 years as the population ages. AF results in impaired patients\' life quality, deteriorated cardiac function and even increased mortality. Antiarrhythmic drugs frequently fail to restore sinus rhythm. Catheter ablation is a valuable treatment approach for AF, even as a first-line therapy strategy in selected patients. Effective electrical pulmonary vein isolation (PVI) is the cornerstone of all AF ablation strategies. Use of radiofrequency (RF) catheter in combination of a three-dimensional electroanatomical mapping system is the most established ablation approach. However, catheter ablation of AF is challenging even sometimes for experienced operators. To facilitate catheter ablation of AF without compromising the durability of the pulmonary vein isolation, \"single shot\" ablation devices have been developed; of them, cryoballoon ablation, is by far the most widely investigated. In this report, we review the current knowledge of AF and discuss the recent evidence in catheter ablation of AF, particularly cryoballoon ablation. Moreover, we review relevant data from the literature as well as our own experience and summarize the key procedural practical techniques in PVI using cryoballoon technology, aiming to shorten the learning curve of the ablation technique and to contribute further to reduction of the disease burden. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 15 Apr 2018; epub ahead of print
Chen S, Schmidt B, Bordignon S, Bologna F, ... Nagase T, Chun KRJ
J Cardiovasc Electrophysiol: 15 Apr 2018; epub ahead of print | PMID: 29663562
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Abstract

Catheter ablation of atrial fibrillation in heart failure with reduced ejection fraction.

Malhi N, Hawkins NM, Andrade JG, Krahn AD, Deyell MW
Atrial fibrillation and heart failure are increasing in prevalence, and frequently coexist. Despite the desire to restore sinus rhythm in heart failure patients, large studies comparing rate control to pharmacologic rhythm control have failed to show superiority of either approach. This may in part be due to the inefficacy and higher risk of adverse effects with antiarrhythmic drugs in HF patients. As such, catheter ablation for atrial fibrillation in patients with heart failure with reduced ejection fraction has been increasingly explored as a treatment modality. We review the contemporary evidence regarding patient selection, efficacy, safety, and impact of catheter ablation on outcomes in patients with atrial fibrillation and heart failure with reduced ejection fraction.

J Cardiovasc Electrophysiol: 05 Apr 2018; epub ahead of print
Malhi N, Hawkins NM, Andrade JG, Krahn AD, Deyell MW
J Cardiovasc Electrophysiol: 05 Apr 2018; epub ahead of print | PMID: 29630760
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Abstract

ICD Therapy - Can We Make a Life-saving Device Less Lethal?

Yousuf O, Spragg D
In the 45 years since the implantable cardioverter-defibrillator (ICD) was first proposed by Dr. Michel Mirowski,(1) this initially maligned therapy(2) has revolutionized our ability to prevent sudden cardiac death. ICDs terminate lethal ventricular arrhythmias (VAs) - namely ventricular tachycardia (VT) or ventricular fibrillation (VF) - by delivering high-voltage energy or antitachycardia pacing (ATP). Large clinical trials have demonstrated convincingly that both for cardiac arrest survivors and for patients at risk of sudden death, ICD implantation achieves a significant, durable mortality advantage over medical therapy alone.(3, 4, 5) However, data from those same studies have demonstrated something else as well: the paradox that life-saving therapy from an ICD confers increased risk of subsequent mortality in rescued patients when compared with similar individuals free from such therapy. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 29 Nov 2015; epub ahead of print
Yousuf O, Spragg D
J Cardiovasc Electrophysiol: 29 Nov 2015; epub ahead of print | PMID: 26616835
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Abstract

Wide QRS complex tachycardia in a patient with complete heart block: What is the mechanism?

Jastrzebski M, Hart R, Czarnecka D
A 34-year-old male was implanted with a dual chamber pacemaker due to a symptomatic complete heart block apparently caused by myocarditis that the patient was experiencing at that time. Despite constant right ventricular pacing, his ejection fraction remained stable at 57%. During routine pacemaker follow-up visits there were no problems with pacing and he remained generally asymptomatic, but complete atrioventricular (AV) block persisted. Unexpectedly, 7 years after pacemaker implantation, he complained of rapid heart palpitations provoked by exertion or emotions. Holter monitoring recorded several episodes of regular wide complex tachycardia (WCT) of 140 - 175 bpm, which correlated with his symptoms (Figure 1). What are the possible mechanisms of WCT in this patient? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 06 Dec 2015; epub ahead of print
Jastrzebski M, Hart R, Czarnecka D
J Cardiovasc Electrophysiol: 06 Dec 2015; epub ahead of print | PMID: 26639166
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Abstract

Young Woman with Wide QRS Tachycardia and No Structural Heart Disease: Do We Need to Look for Something Else?

Chokr MO, Pisani CF, Hardy C, Scanavacca MI
A 23-year-old female patient, previously asymptomatic and without structural heart disease, sought the emergency department with well tolerated palpitations that lasted for 2 hours. The ECG showed a wide QRS complex tachycardia (Figure 1) with left bundle branch block morphology, superior axis, and late transition in the horizontal plane. The Infusion of 6mg of adenosine reversed the arrhythmia, showing right bundle branch block and T-wave inversion in the anterior wall during sinus rhythm. An echocardiogram and cardiac magnetic resonance imaging showed no structural heart disease; Holter monitoring showed PR interval of around 200ms and rare ventricular premature beats. The patient also reported a visual acuity deficit, which began around 6 months before this evaluation. The patient underwent electrophysiological study, which revealed a 76ms HV interval during sinus rhythm. Programmed ventricular pacing (S1: 600ms, S2: 280ms) induced a wide QRS tachycardia similar to the clinic one, with 90ms HV interval (Figure 2). What is the mechanism of the arrhythmia? Do we need to look for something else? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 25 Feb 2016; epub ahead of print
Chokr MO, Pisani CF, Hardy C, Scanavacca MI
J Cardiovasc Electrophysiol: 25 Feb 2016; epub ahead of print | PMID: 26918779
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Abstract

On the Use of CartoSound for Left Atrial Navigation.

Schwartzman D, Zhong H
On the Use of CartoSound for Left Atrial Navigation. Introduction: The utility of "virtual" imaging systems for left atrial (LA) navigation has been hampered by inadequate spatial detail, as well as inaccurate integration of more detailed preoperative images, such as those generated by computed tomography (CT). CartoSound is an intracardiac echocardiography (ICE)-based technology that promises to ameliorate these problems. Our objective was to examine the capabilities and optimal use of CartoSound, both as a stand-alone tool and as a facilitator of CT image integration. Methods and results: In 10 patients, CartoSound models of the LA were generated using each of 4 ICE transducer locations: LA, right atrium (RA), coronary sinus (CS), and esophagus (ESO). Each of these models was used to register CT-derived LA models into the operative workspace. We correlated the comprehensiveness of LA imaging from each transducer location with the quality of the CT registration, as well as the accuracy of mock circumferential antral ablation guided by the CartoSound model alone or by the CT model. The LA transducer location provided the most comprehensive rendering of the LA, which was associated with higher quality CT registration and greater CT-guided mock ablation accuracy. Mock ablation guided by the CartoSound model alone was at least as accurate as CT, although the models were less intuitive. Conclusions: For LA navigation, optimal use of CartoSound may require LA transducer location, which is effective for stand-alone use and as a facilitator of CT image integration. (J Cardiovasc Electrophysiol, Vol. pp. 1-9).

J Cardiovasc Electrophysiol: 30 Dec 2009; epub ahead of print
Schwartzman D, Zhong H
J Cardiovasc Electrophysiol: 30 Dec 2009; epub ahead of print | PMID: 20039990
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Abstract

Paroxysmal Supraventricular Tachycardia with Ventriculoatrial Block and Qrs Duration Shortening: What is the Mechanism?

Lim PC, Chong DT, Tan BY, Ho KL, Teo WS, Ching CK
A 45-year-old man with normal heart structure and function underwent an electrophysiology study for recurrent palpitations. Catheters were placed in the coronary sinus, right ventricular apex and at the His bundle. The baseline electrocardiogram was normal with subtle preexcitation and normal intervals (AH 87ms, HV 50ms). There was poor VA conduction and evident VA dissociation during retrograde conduction studies. Atrial double extra-stimuli showed progressive prolongation of the AH interval with induction of a narrow complex tachycardia of cycle length 440 ms (Fig. 1). The QRS shortened at the onset of tachycardia with subtle changes in the surface electrocardiogram. There was VA dissociation during the tachycardia. A premature ventricular complex (PVC) during His refractory advanced the subsequent His and reset the tachycardia (Fig. 2). This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 09 Nov 2015; epub ahead of print
Lim PC, Chong DT, Tan BY, Ho KL, Teo WS, Ching CK
J Cardiovasc Electrophysiol: 09 Nov 2015; epub ahead of print | PMID: 26552613
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Abstract

Atrial Overdrive Pacing: Is VA Linking Present?

Leventopoulos G, Yue AM
A 57-year-old patient presented with narrow-complex tachycardia (NCT) without discernable P waves on the ECG. He had previously undergone an aortic root and aortic valve replacement 6 years before. At electrophysiological studies, baseline measurements of AH and HV were 92 and 46 ms, respectively. A stable and sustained NCT at the cycle length (CL) of 302 ms was readily inducible. There was 1:1 atrioventricular relationship with a VA interval at the proximal coronary sinus (CS) of 160 ms. Ventricular overdrive pacing (VOP) at a cycle length of 280 ms resulted in VA block and failed to entrain the atrium. Atrial overdrive pacing (AOP) at 280 ms was then performed at the high septal right atrium and coronary sinus ostium (Figs. 1A and 1B). Is VA linking demonstrated by this pacing maneuver? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 09 Nov 2015; epub ahead of print
Leventopoulos G, Yue AM
J Cardiovasc Electrophysiol: 09 Nov 2015; epub ahead of print | PMID: 26552370
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Abstract

LBBB to RBBB Tachycardia. What is the Mechanism?

Nair KK, Namboodiri N, Valaparambil A, Thajudeen A, Tharakan J
A 58-year-old woman was referred for radiofrequency catheter ablation of wide QRS tachycardia that was not terminated with intravenous adenosine and required electrical cardioversion. Twelve-lead ECG was normal during sinus rhythm and transthoracic echocardiography demonstrated no evidence of structural heart disease. The electrophysiological study showed a normal AH interval of 74 ms and HV interval of 42 ms during sinus rhythm. Atrial burst pacing reproducibly induced two tachycardia - 1) wide QRS tachycardia with left bundle branch block (LBBB) morphology with left superior axis and 2) relatively narrow QRS (QRS duration of 110ms) tachycardia with incomplete right bundle block (RBBB) morphology and right inferior axis. Both tachycardias had 1:1 AV relationship and the earliest atrial activation during the tachycardia was recorded in the coronary sinus (CS) dipoles 5,6 placed at CS. Figure 1 shows spontaneous transition from the tachycardia with LBBB morphology to tachycardia with RBBB morphology. What are the likely mechanisms of the tachycardia and the transition? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 25 Feb 2016; epub ahead of print
Nair KK, Namboodiri N, Valaparambil A, Thajudeen A, Tharakan J
J Cardiovasc Electrophysiol: 25 Feb 2016; epub ahead of print | PMID: 26915351
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Abstract

Reader- and Instrument-Dependent Variability in the Electrocardiographic Assessment of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy.

Jain R, Tandri H, Daly A, Tichnell C, ... Calkins H, Dalal D
Variability in ECG Assessment in ARVD/C. Introduction: Despite the use of standardized definitions, widely varying prevalence estimates of electrocardiographic (ECG) features related to arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) have been reported in different cohorts. This study was aimed at examining the variability in the ECG interpretation resulting from the same reader, different readers, and using different ECG-resolutions. Methods and results: Blinded to other clinical data, 2 readers examined quantitative and qualitative ECG features of 20 (10 ARVD/C) randomly selected individuals. ECGs were recorded at standard-speed (SS) and double-speed-double-amplitude (DS) settings. The SS ECGs were scanned, magnified 4×, and evaluated using electronic calipers (EL). One reader repeated all measurements. For both readers, the intraclass correlation coefficient (ICC) for the measurement of QRS duration was good between conventional and electronic evaluation [DS vs EL: Reader 1-0.64 (0.52-0.73); Reader 2-0.67 (0.55-0.76)][SS vs EL: Reader 1-0.60 (0.47-0.70); Reader 2-0.60 (0.47-0.70)]. Using the same resolution, the intrareader ICC was good for SS [0.70 (0.59-0.78)], DS [0.85 (0.80-0.90)], and EL [0.70 (0.69-0.83)] resolutions, but deteriorated for interreader comparisons [0.50 (0.36-0.62), 0.75 (0.66-0.82), and 0.75 (0.66-0.82), respectively]. For qualitative parameters, the intra- and interreader agreement was inconsistent for all but 2 parameters. Both readers were in perfect agreement while interpreting right precordial T-wave inversion [κ= 1] and right bundle branch block morphology (RBBB) [κ= 0.83 (0.5-1.0)] even when using SS resolution. Conclusions: Right precordial t-wave inversion and RBBB are the only ECG parameters that can be detected consistently even using the conventionally used ECG-resolution. The substantial variability in evaluation of other parameters is not improved even with the use of higher resolutions. (J Cardiovasc Electrophysiol, Vol. pp. 1-8).

J Cardiovasc Electrophysiol: 30 Nov 2010; epub ahead of print
Jain R, Tandri H, Daly A, Tichnell C, ... Calkins H, Dalal D
J Cardiovasc Electrophysiol: 30 Nov 2010; epub ahead of print | PMID: 21114702
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Abstract

Wide QRS complex tachycardia in a patient with concealed accessory pathway: What is the mechanism?

Jastrzebski M, Pitak M, Rudzinsk A, Czarnecka D
A 15-year-old boy with vague complaints of palpitations/chest discomfort was found on standard 12-lead ECG to have frequent long episodes of wide QRS complex tachycardia of approximately 100 bpm (Fig. 1). At first, it was considered an accelerated idioventricular rhythm, but the apparently low amplitude initial part of the QRS in some leads suggested a P wave, albeit of a different morphology than the sinus P wave, preceding the QRS complexes. Electrophysiological study showed normal atrioventricular conduction (AH, HV intervals and Wenckebach point cycle lengths of 80 ms, 46 ms and 330 ms, respectively), no preexcitation and decremental concentric retrograde conduction on coronary sinus catheter (VA interval of 128 ms to 254 ms). During incremental atrial pacing, surprisingly, narrow QRS tachycardia was induced, which had been diagnosed as orthodromic atrioventricular reentrant tachycardia using a concealed right lateral accessory pathway (Fig 2). This tachycardia promptly terminated, followed spontaneously by wide QRS complex tachycardia of 102 bpm, identical to the clinical arrhythmia (Fig 2); many other spontaneous episodes of this wide QRS tachycardia were observed. The intracardiac tracings left no doubt that the QRS was, indeed, preceded by a non-sinus P wave, albeit with a very short PR interval of 50 ms and no His bundle deflection before QRS complexes (Fig. 2). What could be the mechanism of this wide QRS tachycardia in a patient without overt preexcitation? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Apr 2016; epub ahead of print
Jastrzebski M, Pitak M, Rudzinsk A, Czarnecka D
J Cardiovasc Electrophysiol: 19 Apr 2016; epub ahead of print | PMID: 27094587
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Abstract

Athletes and Arrhythmias.

Link MS, Mark Estes NA
Athletes and Arrhythmias. Athletes are thought the healthiest segment of the population. Yet, there is a general appearance that athletes are more prone to sudden cardiac death and arrhythmias than nonathletes. Bradycardias in athletes are nearly universal, but advanced heart block is usually pathologic. Athletes may be more prone to atrial fibrillation, but not likely to other types of supraventricular tachycardias. Sudden cardiac death in athletes is rare in the absence of heart disease, with the exception of commotio cordis. Treatment strategies for athletes are focused for the return to athletics. Guidelines for treatment will be derived from the 36th Bethesda Guidelines for athletes, and the European Society of Cardiology (ESC) guidelines for athletes. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 04 Jun 2010; epub ahead of print
Link MS, Mark Estes NA
J Cardiovasc Electrophysiol: 04 Jun 2010; epub ahead of print | PMID: 20522153
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Abstract

Transbaffle multielectrode mapping of atrial flutter post double switch operation.

Haldar S, Porta-Sanchez A, Oechslin E, Downar E, Benson L, Nair K
A 26-year-old woman with congenitally corrected transposition of the great arteries (ccTGA) had undergone a double-switch corrective surgery consisting of a Mustard procedure (bovine pericardial baffles and hemashield grafts) and arterial switch (Jatene technique). She subsequently developed drug refractory atrial flutter and underwent ablation. An Agilis sheath (St Jude Medical, USA) and a long BRK 1 needle was used for the transbaffle puncture guided by transoesophageal echocardiography. Activation maps of the systemic venous antrum (SVA) and then the PVA (Fig. 1A) were created with a 20-pole PentaRay® catheter using the CARTO CONFIDENSE (TM) (Biosense Webster, USA) module. Over 2000 activation points were obtained in 18 minutes and a large scar was identified on the lateral aspect of the PVA close to the origin of the pulmonary veins. The activation map indicated a macrorentrant circuit between the scar and the tricuspid valve annulus (TVA) with clear demonstration of early meets late (Fig. 1B). An ablation line, using contact force sensing catheter with RF energy ranging from 30-40W, was drawn from the scar to the TVA during which atrial flutter terminated (Fig. 1C). There were no complications and the patient remains arrhythmia free 3 months post procedure. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 18 Apr 2016; epub ahead of print
Haldar S, Porta-Sanchez A, Oechslin E, Downar E, Benson L, Nair K
J Cardiovasc Electrophysiol: 18 Apr 2016; epub ahead of print | PMID: 27090771
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Abstract

Dual-Loop Bi-Atrial Macroreentrant Atrial Tachycardia in a Patient with Modified Cox Maze IV: Where is the Initial Ablation Target?

Hayashi T, Mitsuhashi T, Fujita H, Momomura SI
A 75-year-old man with atrial fibrillation, who underwent valve (mitral and tricuspid) plasty with a modified Cox-Maze IV, was referred for the ablation of atrial tachycardia (AT). At the beginning of the procedure, the baseline tachycardia cycle length (TCL) was 300 ms. No pulmonary vein potentials were recorded, and a three-dimensional (3D) activation map (CARTO, Biosense Webster Inc., CA, USA) showed a clockwise peri-mitral atrial tachycardia (PMAT) pattern (Fig. 1). With the entrainment pacing from the multiple sites at the left atrium (LA) in the 7- 2 o\'clock direction of the mitral annulus (MA), a post-pacing interval (PPI) - TCL was ≤20ms (Fig. 1). The PPI - TCL at the multiple sites of the coronary sinus (CS) opposite of LA 3-6 o\'clock direction of MA was ≤20 ms, although the PPI - TCL at the LA 3-6 o\'clock direction of MA was >20 ms. Interestingly, the PPI - TCL at both the CS ostium and the right atrial septum was ≤20 ms. Furthermore, the RA activation map showed that the counter-clockwise cavotricuspid isthmus (CTI) dependent AT although the PPI - TCL at the CTI was >20 ms (Fig. 1). Based upon these observations, where is the initial ablation target? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 16 Nov 2015; epub ahead of print
Hayashi T, Mitsuhashi T, Fujita H, Momomura SI
J Cardiovasc Electrophysiol: 16 Nov 2015; epub ahead of print | PMID: 26572501
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Abstract

Patients Treated with Catheter Ablation for Atrial Fibrillation Have Long-Term Rates of Death, Stroke, and Dementia Similar to Patients Without Atrial Fibrillation.

Bunch TJ, Crandall BG, Weiss JP, May HT, ... Lappe DL, Day JD
Outcomes in Patients With AF. Introduction: Atrial fibrillation (AF) adversely impacts mortality, stroke, heart failure, and dementia. AF ablation eliminates AF in most patients. We evaluated the long-term impact of AF ablation on mortality, heart failure (HF), stroke, and dementia in a large system-wide patient population. Methods: A total of 4,212 consecutive patients who underwent AF ablation were compared (1:4) to 16,848 age/gender matched controls with AF (no ablation) and 16,848 age/gender matched controls without AF. Patients were enrolled from the large ongoing prospective Intermountain AF study and were followed for at least 3 years. Results: Of the 37,908 patients, mean age 65.0 ± 13 years, 5,667 (14.9%) died, 1,296 (3.4%) had a stroke, and 1,096 (2.9%) were hospitalized for HF over >3 years of follow-up. AF ablation patients were less likely to have diabetes, but were more likely to have hypertension, HF, and significant valvular heart disease. AF ablation patients had a lower risk of death and stroke in comparison to AF patients without ablation. Alzheimer\'s dementia occurred in 0.2% of the AF ablation patients compared to 0.9% of the AF no ablation patients and 0.5% of the no AF patients (P < 0.0001). Other forms of dementia were also reduced significantly in those treated with ablation. Compared to patients with no AF, AF ablation patients had similar long-term rates of death, dementia, and stroke. Conclusions: AF ablation patients have a significantly lower risk of death, stroke, and dementia in comparison to AF patients without ablation. AF ablation may eliminate the increased risk of death and stroke associated with AF. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 17 Mar 2011; epub ahead of print
Bunch TJ, Crandall BG, Weiss JP, May HT, ... Lappe DL, Day JD
J Cardiovasc Electrophysiol: 17 Mar 2011; epub ahead of print | PMID: 21410581
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Electrocardiographic versus Echocardiographic Optimization of the Interventricular Pacing Delay in Patients Undergoing Cardiac Resynchronization Therapy.

Tamborero D, Vidal B, Tolosana JM, Sitges M, ... Brugada J, Mont L
Electrocardiographic VV Optimization. Introduction: Echocardiographic optimization of the VV interval may improve CRT response, but it is time-consuming and not routinely performed. The aim of this study was to compare the response to cardiac resynchronization therapy (CRT) when the interventricular pacing (VV) interval was optimized by Tissue Doppler Imaging (TDI) to CRT response when it was optimized following QRS width criteria. Methods and results: The study included 156 consecutive CRT patients with severe heart failure and left bundle-branch block configuration. Atrioventricular interval was selected according to a pulsed Doppler assessment, and VV optimization was randomly assigned to echocardiography (ECHO group, n = 78) or electrocardiography (ECG group, n = 78). Optimal VV was defined for the ECHO group as producing the best LV intraventricular synchrony according to TDI displacement curves and for the ECG group as resulting in the narrowest QRS measured from the earliest deflection. At 6-month follow-up, percentage of echocardiographic responders (defined as neither death nor heart transplantation and a LV end-systolic volume reduction >10%) was higher in the ECG optimized group (50.0% vs 67.9%; P = 0.023), whereas clinical response (defined as neither death nor heart transplantation and >10% improvement in the 6-minute walking test) was similar in both groups (71.8% vs 73.1%; P = 0.858). Conclusions: VV optimization based on QRS width obtained a higher percentage of responders in terms of LV reverse remodeling compared to the TDI method. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 03 Jun 2011; epub ahead of print
Tamborero D, Vidal B, Tolosana JM, Sitges M, ... Brugada J, Mont L
J Cardiovasc Electrophysiol: 03 Jun 2011; epub ahead of print | PMID: 21635609
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The Challenging Face of Focal Atrial Tachycardia in the Post AF Ablation Era.

Heck PM, Rosso R, Kistler PM
Focal Atrial Tachycardia in the Post AF Ablation Era. Radiofrequency ablation (RFA) for atrial fibrillation (AF) has become one of the most common catheter ablation procedures performed worldwide. As experience and success in treating patients with paroxysmal AF have increased, more centers are performing ablation for persistent AF. Optimal results may require ablation beyond the pulmonary veins with extensive biatrial substrate modification required in some cases to restore sinus rhythm. On the road to sinus rhythm atrial tachycardias are generally encountered either acutely within the index procedure or following. This has led to an increase in the frequency of focal atrial tachycardia and a need to review our understanding and approach to this and how it differs following substrate modification in contrast with the de novo setting. This review aims to describe the differences in responsible mechanism and its translation to mapping and ablation of focal AT particularly in the post ablation atria (paAT). (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 03 Jun 2011; epub ahead of print
Heck PM, Rosso R, Kistler PM
J Cardiovasc Electrophysiol: 03 Jun 2011; epub ahead of print | PMID: 21635611
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Atrial Remodeling in an Ovine Model of Anthracycline-Induced Nonischemic Cardiomyopathy: Remodeling of the Same Sort.

Lau DH, Psaltis PJ, Mackenzie L, Kelly DJ, ... Worthley SG, Sanders P
Atrial Remodeling in Doxorubicin Cardiomyopathy. Introduction: All preclinical studies of atrial remodeling in heart failure (HF) have been confined to a single model of rapid ventricular pacing. To evaluate whether the atrial changes were specific to the model or represented an end result of HF, this study aimed to characterize atrial remodeling in an ovine model of doxorubicin-induced cardiomyopathy. Methods and results: Fourteen sheep, 7 with cardiomyopathy induced by repeated intracoronary doxorubicin infusions and 7 controls, were studied. The development of HF was monitored by cardiac imaging and hemodynamic parameters. Open chest electrophysiological study was performed using custom-made 128-electrode epicardial plaque assessing effective refractory period (ERP) and conduction velocity. Atrial tissues were harvested for structural analysis. The HF group had demonstrable moderate global HF (left ventricular ejection fraction [LVEF]: 37.1 vs 46.4%; P = 0.003) and showed the following compared to controls: left atrial dilatation (P = 0.02) and dysfunction (P = 0.005); longer P-wave duration (P < 0.05); higher ERP at all cycle lengths (P </= 0.002) and locations (P < 0.001); slower conduction velocity (P < 0.001); increased conduction heterogeneity index (P < 0.001); increased atrial fibrosis (right atrial [RA]: 5.9 +/- 2.6 vs 2.8 +/- 0.9%; P < 0.0001, left atrial [LA]: 3.7 +/- 2.2 vs 2.4 +/- 1.1%; P = 0.002), and longer induced atrial fibrillation (AF) episodes (16 +/- 22 vs 2 +/- 3 seconds; P = 0.04). Conclusion: In this model of HF, there was significant atrial remodeling characterized by atrial enlargement/dysfunction, increased fibrosis, slowed/heterogeneous conduction, and increased refractoriness associated with more sustained AF. These findings appear the "same sort" to previous models of HF implicating a final common substrate leading to the development of AF in HF. (J Cardiovasc Electrophysiol, Vol. pp. 1-8).

J Cardiovasc Electrophysiol: 28 Jul 2010; epub ahead of print
Lau DH, Psaltis PJ, Mackenzie L, Kelly DJ, ... Worthley SG, Sanders P
J Cardiovasc Electrophysiol: 28 Jul 2010; epub ahead of print | PMID: 20662987
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Upgrading to Biventricular Pacing Guided by Pressure-Volume Loop Analysis During Implantation.

Hm Delnoy PP, Ottervanger JP, Vos DH, Elvan A, ... Steendijk P, VAN Hemel NM
Pressure-Volume Loop Analyses during CRT Implants. Introduction: cardiac resynchronization therapy (CRT) may improve prognosis in patients with chronic right ventricular (RV) pacing, and optimal lead position can decrease nonresponders. We evaluated the clinical and echocardiographic response to CRT in patients with previous chronic RV pacing, using pressure-volume loop analyses to determine the optimal left ventricular (LV) lead position during implantation. Methods and results: In this single-blinded, randomized, controlled crossover study, 40 patients with chronic RV apical pacing and symptoms of heart failure, decreased LV ejection fraction (LVEF) or dyssynchrony were included. During implantation, stroke work (SW), LVEF, cardiac output, and LV dP/dt(max) were assessed by a conductance catheter. Clinical and echocardiographic response was studied during a 3-month period of RV pacing (RV period, LV lead inactive) and a 3-month period of biventricular pacing (CRT period). At the optimal LV lead position, SW (37 ± 41%), LVEF (16 ± 13%), cardiac output (29 ± 16%), and LV dP/dt(max) increased (11 ± 11%) significantly during biventricular pacing compared to baseline. Additional benefit could be achieved by pressure-volume loop guided selection of the best left-sided pacing location. RV outflow tract pacing did not improve hemodynamics. During follow-up, symptoms improved during CRT, VO(2,max) increased 10% and significant improvements in LVEF, LV volumes, and mitral regurgitation were observed as compared to the RV period. Conclusions: CRT in patients with chronic RV pacing causes significant improvement of both LV function as measured by pressure-volume loops during implantation and clinical and echocardiographic improvement during follow-up. Pressure-volume loops during implantation may facilitate selection of the most optimal pacing site. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 07 Dec 2010; epub ahead of print
Hm Delnoy PP, Ottervanger JP, Vos DH, Elvan A, ... Steendijk P, VAN Hemel NM
J Cardiovasc Electrophysiol: 07 Dec 2010; epub ahead of print | PMID: 21134027
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Abstract

Ablation Efficacy and Electrical Morphology of a Novel 18-Hole Open-Irrigated Catheter.

Ning XH, Tang M, Tang Y, Tian Y, Zhang S
Ablation Efficacy and Electrical Morphology. Introduction: The 6-hole open-irrigated catheter (SHOI) is increasingly used in radiofrequency (RF) ablation of arrhythmias. However, deep transmural lesions are not always achieved, and volume overload caused by irrigated ablation is another problem that should be concerned. The purpose of this study was to analyze and compare the ablation effect and electrical morphology between a novel 18-hole open-irrigated catheter (EHOI) and SHOI. Methods and results: The heart was exposed through a median sternotomy in 12 anesthetized dogs, and the chest cavity was filled with heparinized saline. Bipolar contact pericardial electrograms of both catheters were recorded. Lesions were created under all permutations of the following conditions: RF energy 30 and 40 W for 60 seconds, contact force at 10, 30, and 50 g, electrode orientation horizontal to the tissue, irrigation rate 10 mL/min for EHOI and 17 mL/min for SHOI. The EHOI created deeper lesions than SHOI (5.77 ± 1.37 mm vs 4.98 ± 1.22 mm at power of 30 W, P < 0.05; 7.16 ± 1.15 mm vs 6.02 ± 1.04 mm at power of 40 W, P < 0.01), and there was a trend of larger lesion volume for EHOI (312 ± 141 mm(3) vs 259 ± 108 mm(3) at power of 30 W, 536 ± 200 mm(3) vs 451 ± 180 mm(3) at power of 40 W, P > 0.05). No significant difference in electrogram morphology between 2 catheters was detected. Conclusions: The mapping electrograms of EHOI and SHOI were not significantly different. Compared with SHOI, EHOI more effectively produced deeper lesions at a lower rate of irrigation perfusion. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print
Ning XH, Tang M, Tang Y, Tian Y, Zhang S
J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print | PMID: 21235665
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Abstract

Effect of Elapsed Time From Coronary Revascularization to Implantation of a Cardioverter Defibrillator on Long-Term Survival in the MADIT-II Trial.

Barsheshet A, Goldenberg I, Moss AJ, Huang DT, ... Klein HU, Guetta V
Coronary Revascularization and Long-Term Mortality in MADIT-II. Introduction: Coronary revascularization (CR) may reduce arrhythmia risk and improve long-term outcome in patients with left ventricular dysfunction. This study was designed to evaluate the effect of elapsed time from CR on long-term mortality and arrhythmic risk among patients who receive an implantable cardioverter defibrillator (ICD). Methods and results: We evaluated the risk of 8-year mortality by elapsed time from CR to ICD implantation (categorized as: no CR; recent CR [<2 years]; or nonrecent CR [≥2 years], and assessed as a continuous measure) among 720 ICD recipients enrolled in the Multicenter Automatic Defibrillator Trial-II. At 8years of follow-up, patients who did not undergo CR and those who underwent nonrecent CR had significantly higher mortality rates than patients who underwent recent CR (54%, 54%, and 36%, respectively; P < 0.001). Multivariate analysis demonstrated that no- and nonrecent CR were associated with respective 48% (P = 0.022) and 67% (P < 0.001) increases in mortality risk compared with recent CR. Assessment of time from CR as a continuous measure showed that every year elapsed from CR was associated with an adjusted 6% increase in 8-year mortality (P < 0.001), and in respective 6% (P < 0.001) and 6% (P = 0.003) increased risk for in-trial appropriate ICD therapy of ventricular tachyarrhythmias and appropriate ICD shocks. Conclusions: We observed a direct relationship between elapsed time from CR and long-term mortality following ICD implantation. The favorable long-term effect on outcome of recent CR may be related to a time-dependent effect of CR on ventricular arrhythmic burden and the need for appropriate ICD shocks. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 27 May 2011; epub ahead of print
Barsheshet A, Goldenberg I, Moss AJ, Huang DT, ... Klein HU, Guetta V
J Cardiovasc Electrophysiol: 27 May 2011; epub ahead of print | PMID: 21615813
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Abstract

Electrocardiographic Characteristics in Patients With Pulmonary Sarcoidosis Indicating Cardiac Involvement.

Schuller JL, Olson MD, Zipse MM, Schneider PM, ... Varosy PD, Sauer WH
ECG Characteristics of Cardiac Sarcoidosis. Introduction: Sarcoidosis is a multisystem granulomatous disease that can affect the heart. Early identification of cardiac sarcoidosis (CS) is critical because sudden death can be the initial presentation. We sought to evaluate the potential role of the ECG for identification of cardiac involvement in a cohort of patients with biopsy-proven pulmonary sarcoidosis. Methods: Our cohort consisted of referred patients with biopsy-proven pulmonary sarcoidosis who demonstrated symptoms consistent with cardiac involvement. The ECG characteristics collected were PR, QRS duration, QT interval, rate, bundle branch block (BBB), fragmented QRS (fQRS). QRS fragmentation was defined as 2 anatomically contiguous leads demonstrating RSR\' patterns in the absence of BBB. Results: There were 112 subjects included in the cohort. Of the 52 subjects eventually diagnosed with CS, 39 had an ECG demonstrating fQRS while 21 of the 60 of non-CS patients had fQRS (75% vs 33.9%, P < 0.01). A RBBB or LBBB pattern were both more prevalent in the CS population (RBBB: 23.1% vs 6.7%, P = 0.016; LBBB: 3.8% vs 1.7%, P = 0.6). QRS duration remained significantly associated with CS after exclusion of those with BBB (93.5 +/- 10.6 vs 88 +/- 11 ms; P = 0.04). When fQRS and bundle branch block were combined, 90.4% of CS patient\'s ECGs contained at least one of the features, compared to 36.7% of noncardiac CS (P < 0.01). Conclusions: The presence of fQRS or BBB pattern in patients with pulmonary sarcoidosis is associated with cardiac involvement and therefore should prompt further evaluation. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 27 May 2011; epub ahead of print
Schuller JL, Olson MD, Zipse MM, Schneider PM, ... Varosy PD, Sauer WH
J Cardiovasc Electrophysiol: 27 May 2011; epub ahead of print | PMID: 21615816
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Abstract

Vagal Paroxysmal Atrial Fibrillation: Prevalence and Ablation Outcome in Patients Without Structural Heart Disease.

Rosso R, Sparks PB, Morton JB, Kistler PM, ... Medi C, Kalman JM
Prevalence of Vagal Paroxysmal Atrial Fibrillation. Introduction: The prevalence of vagal and adrenergic atrial fibrillation (AF) and the success rate of pulmonary vein isolation (PVI) are not well defined. We investigated the prevalence of vagal and adrenergic AF and the ablation success rate of antral pulmonary vein isolation (APVI) in patients with these triggers compared with patients with random AF. Methods and results: Two hundred and nine consecutive patients underwent APVI due to symptomatic drug refractory paroxysmal AF. Patients were diagnosed as vagal or adrenergic AF if >90% of AF episodes were related to vagal or adrenergic triggers; otherwise, a diagnosis of random AF was made. Clinical, electrocardiogram (ECG), and Holter follow-up was every 3 months in the first year and every 6 months afterward and for symptoms. Of 209 patients, 57 (27%) had vagal AF, 14 (7%) adrenergic AF, and 138 (66%) random AF. Vagal triggers were sleep (96.4%), postprandial (96.4%), late post-exercise (51%), cold stimulus (20%), coughing (7%), and swallowing (2%). At APVI, 94.3% of patients had isolation of all veins. Twenty-five (12%) patients had a second APVI. At a follow-up of 21 +/- 15 months, the percentage of patients free of AF was 75% in the vagal group, 86% in the adrenergic group, and 82% for random AF (P = 0.51). Conclusion: In patients with PAF and no structural heart disease referred for APVI, vagal AF is present in approximately one quarter. APVI is equally effective in patients with vagal AF as in adrenergic and random AF. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 21 Dec 2009; epub ahead of print
Rosso R, Sparks PB, Morton JB, Kistler PM, ... Medi C, Kalman JM
J Cardiovasc Electrophysiol: 21 Dec 2009; epub ahead of print | PMID: 20021523
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Abstract

Long RP\' Tachycardia with Unusual Entrainment Responses: What is the Mechanism?

Doi A, Takagi M, Fujimoto K, Kakihara J, ... Tatsumi H, Yoshiyama M
A 71-year-old man with palpitation was referred for electrophysiological study and radiofrequency ablation. Baseline findings of 12-lead electrocardiogram during sinus rhythm and echocardiography were normal. Atrio-His (AH) and His-ventricular (HV) intervals were measured as 113 and 40 ms, respectively. Dual atrioventricular (AV) nodal physiology was observed during programmed atrial stimulation. The earliest atrial activation during ventricular constant pacing was recorded at His bundle region, and para-Hisian pacing showed AV nodal pattern. Short RP\' tachycardia (SVT 1) accompanied by a jump-up in the AH interval was induced by atrial extra stimulation or atrial constant pacing (Figure 1). During SVT 1, the AH and HV intervals were measured as 453 and 40 ms, respectively, and the earliest atrial activation was recorded at the His bundle region. Ventricular extrastimuli delivered during SVT 1 when the His bundle is refractory did not reset the atrial cycle. Figure 2A shows a transition from SVT 1 to long RP\' tachycardia (SVT 2) with a true atrial-atrial-ventricular (AAV) response after cessation of ventricular entrainment pacing (VEP) during SVT 1. During SVT 2, the AH and HV intervals were measured as 125 and 42 ms, respectively, and the earliest atrial activation was recorded at the coronary sinus (CS) ostium. Ventricular extrastimuli delivered during SVT 2 did not reset the atrial cycle, and VEP during SVT2 was performed (Figure 2B). What is the mechanism underlying the two entrainment responses? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 18 Apr 2016; epub ahead of print
Doi A, Takagi M, Fujimoto K, Kakihara J, ... Tatsumi H, Yoshiyama M
J Cardiovasc Electrophysiol: 18 Apr 2016; epub ahead of print | PMID: 27090609
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Abstract

Tachycardia-Induced Cardiomyopathy in Patients With Idiopathic Ventricular Arrhythmias: The Incidence, Clinical and Electrophysiologic Characteristics, and the Predictors.

Hasdemir C, Ulucan C, Yavuzgil O, Yuksel A, ... Aydin M, Can LH
Idiopathic Ventricular Arrhythmias and Cardiomyopathy. Introduction: Idiopathic ventricular arrhythmias in the form of monomorphic premature ventricular contractions (PVC) and/or ventricular tachycardia (VT) can cause tachycardia-induced cardiomyopathy (TICMP). The aim of this study was to determine the incidence, clinical and electrophysiologic characteristics, and the predictors of TICMP in patients with idiopathic ventricular arrhythmias. Methods: Study population consisted of 249 consecutive patients (148 F/101 M, 45 ± 20 y/o) with frequent PVCs and/or VT. All patients underwent transthoracic echocardiography and 24-hour Holter monitoring. TICMP was defined as left ventricular ejection fraction (LVEF) of ≤50% in the absence of any detectable underlying heart disease and improvement of LVEF ≥15% following effective treatment of index ventricular arrhythmia. Results: Seventeen (6.8%) patients had TICMP. Patients with TICMP compared to patients with preserved LVEF were more likely to be male (65% vs 39%, P = 0.043) and asymptomatic (29% vs 9%, P = 0.018), and were more likely to have higher PVC burden (29.4 ± 9.2 vs 8.1 ± 7.4, P < 0.001), persistence of PVCs throughout the day (65% vs 22%, P = 0.001), and repetitive monomorphic VT (24% vs 0.9%, P < 0.001). PVC burden of 16% by ROC curve analysis best separated the patients with TICMP compared to patients with preserved LVEF (sensitivity 100%, specificity 87%, area under curve 0.96). Conclusions: TICMP was relatively common (∼1 in every 15 patients) in our study population. The predictors of TICMP were male gender, absence of symptoms, PVC burden of ≥16%, persistence of PVCs throughout the day, and the presence of repetitive monomorphic VT. (J Cardiovasc Electrophysiol, Vol. pp. 00-00).

J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print
Hasdemir C, Ulucan C, Yavuzgil O, Yuksel A, ... Aydin M, Can LH
J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print | PMID: 21235667
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Abstract

Incidence of Silent Cerebral Thromboembolic Lesions After Atrial Fibrillation Ablation May Change According To Technology Used: Comparison of Irrigated Radiofrequency, Multipolar Nonirrigated Catheter and Cryoballoon.

Gaita F, Leclercq JF, Schumacher B, Scaglione M, ... Cesarani F, Blandino A
AF Ablation Technologies and Silent Cerebral Ischemic Lesions. Introduction: Silent cerebral ischemic lesions have recently emerged as the most frequent complications after pulmonary vein isolation (PVI). To reduce thromboembolic complications, new types of catheters and energy source have been introduced in clinical practice. The study purpose is to compare the incidence of new silent cerebral ischemic events in patients with paroxysmal atrial fibrillation (PAF) undergoing PVI with different ablation technologies. Methods and results: One hundred and eight patients (67% men; age 56 ± 9 years) with PAF were enrolled in a consecutive manner to undergo PVI performed with irrigated radiofrequency (RF) catheter (Group 1, 36 patients), multielectrode catheter (PVAC) associated with duty-cycled RF generator (Group 2, 36 patients) and cryoballoon (Group 3, 36 patients). The protocol included a cerebral magnetic resonance imaging before and after the procedure. After PVI, the following patients showed new silent cerebral ischemic lesions at postprocedural cerebral MRI: 3 patients in Group 1 (8.3%), 14 patients in Group 2 (38.9%), 2 patients in Group 3 (5.6%). PVAC related to higher incidence of silent cerebral ischemic events compared to irrigated RF (P = 0.002) and cryoballoon (P = 0.001), whereas no statistical differences were found between irrigated RF catheter and cryoballoon groups (8.3% vs 5.6%, P = 0.5). At the multivariate analysis, the only independent predictor of new ischemic asymptomatic cerebral lesions after PVI was ablation performed with PVAC (OR 1.48 95% CI 1.19-1.62, P < 0.001). Conclusion: The incidence of silent cerebral lesions after PVI is different depending on technologies used: PVAC increases the risk of 1.48 times compared to irrigated RF and cryoballoon ablation. (J Cardiovasc Electrophysiol, Vol. pp. 1-8).

J Cardiovasc Electrophysiol: 01 Apr 2011; epub ahead of print
Gaita F, Leclercq JF, Schumacher B, Scaglione M, ... Cesarani F, Blandino A
J Cardiovasc Electrophysiol: 01 Apr 2011; epub ahead of print | PMID: 21453372
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Abstract

Demographic Profile of Patients Undergoing Catheter Ablation of Atrial Fibrillation.

Hoyt H, Nazarian S, Alhumaid F, Dalal D, ... Berger R, Calkins H
Demographic Profile of Patients Undergoing AF Ablation. Background: Catheter ablation is a widely accepted treatment for drug refractory atrial fibrillation (AF). The purpose of our study was to examine secular trends in the demographic profile of patients undergoing AF ablation. Methods and results: Data for 792 patients who underwent catheter ablation for AF at Johns Hopkins Hospital between years 2001 and 2009 were systematically reviewed. There has been a steady increase in total number of procedures and repeat procedures. The majority of patients undergoing AF ablation at our institution are men (76.6%). Females accounted for 36.0% of patients in 2001 versus 19.6% in 2009. A total of 93.3% of patients undergoing AF ablation were Caucasian. The mean age of patients has increased over time (52 years in 2001 to 60 years in 2009, P = 0.015) and the number of antiarrhythmic drugs (AADs) used prior to first ablation has decreased (2.3 to 1.2, P = 0.009). In addition, the mean duration of AF prior to first referral has decreased (7.8 years in 2001 vs 4.2 years in 2009). Conclusion: There is a significant gender and racial disparity in patients undergoing AF ablation favoring Caucasian men that warrants further investigation. We also observed a significant increase in age of patients, decrease in number of AADs, and increase in number of repeat procedures. These results are important when interpreting outcomes of AF ablation and designing future trials. (J Cardiovasc Electrophysiol, Vol. pp. 1-5).

J Cardiovasc Electrophysiol: 09 Mar 2011; epub ahead of print
Hoyt H, Nazarian S, Alhumaid F, Dalal D, ... Berger R, Calkins H
J Cardiovasc Electrophysiol: 09 Mar 2011; epub ahead of print | PMID: 21385269
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Abstract

Prevalence and Predictors of Complications of Radiofrequency Catheter Ablation for Atrial Fibrillation.

Baman TS, Jongnarangsin K, Chugh A, Suwanagool A, ... Morady F, Oral H
Complications of Atrial Fibrillation Ablation. Introduction: Up to 6% of patients experience complications after radiofrequency catheter ablation (RFA) of atrial fibrillation (AF). The purpose of this study is to determine the prevalence and predictors of periprocedural complications after RFA for AF. Methods and results: The subjects were 1,295 consecutive patients (age = 60 ± 10 years) who underwent RFA (n = 1,642) for paroxysmal (53%) or persistent AF (47%) from January 2007 to January 2010. A complication occurred in 57 patients (3.5%); a vascular access complication in 31 (1.9%); pericardial tamponade in 20 (1.2%); a thromboembolic event in 4 (0.2%); deep venous thrombosis in 1 (<0.01%); and pulmonary vein stenosis in 1 patient (<0.01%). There were no procedure-related deaths. On multivariate analysis, female gender (OR = 2.27; ±95% CI: 1.31-2.57, P < 0.01) and procedures performed in July or August (OR = 2.10; ±95% CI: 1.16-3.80, P = 0.01) were independent predictors of any complication. For vascular complications, treatment with clopidogrel (OR = 4.40; ±95% CI: 1.43-13.53, P = 0.01), female gender (OR = 3.65; ±95% CI: 1.72-7.75, P < 0.01) and performing RFA in July or August (OR = 2.71; ±95% CI: 1.25-5.87, P = 0.01) were independent predictors. The only predictor of cardiac tamponade was prior RFA (OR = 3.32; ±95% CI: 0.95-11.61; P < 0.05). Conclusion: Prevalence of perioperative complications for RFA of AF is 3.5% and vascular access complications constitute the majority. The need for clopidogrel therapy should be carefully considered prior to RFA. At teaching institutions close supervision should be exercised during vascular access early in the year. Improvements in ablation technology and elimination of the need for repeat procedures may decrease the risk of pericardial tamponade. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print
Baman TS, Jongnarangsin K, Chugh A, Suwanagool A, ... Morady F, Oral H
J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print | PMID: 21235674
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Abstract

Twelve-Lead ECG Interpretation in a Patient With Presumed Left Atrial Flutter Following AF Ablation.

Shah D
Twelve-Lead ECG Interpretation in a Patient With Presumed Left Atrial Flutter. The 12-lead ECG provides valuable clues to the mechanism and origin of organized tachycardias occurring in patients after catheter ablation of atrial fibrillation. Many of these patients have cavotricuspid isthmus-dependent flutter, and therefore it is important to be aware of variations from the norm of typical flutter. Left atrial reentrant tachycardias are, however, the most common arrhythmias encountered after catheter ablation of atrial fibrillation. The underlying circuits are typically formed around anatomic obstacles such as the PV ostia or the mitral valve, and facilitated by slow conducting, low voltage isthmuses through gaps through and bordering ablation lesions. They can be recognized by the presence of 12-lead synchronous iso-electric intervals separating flutter waves. Continuous activity ECGs (without 12-lead iso-electric intervals) are typical of larger size reentrant circuits not dependent on markedly slow conducting isthmuses. Delayed bystander activity can also however obscure iso-electric intervals. The integration of informed ECG analysis with a detailed knowledge of the index ablation strategy can provide an optimum platform for successful catheter ablation of these often very symptomatic arrhythmias. (J Cardiovasc Electrophysiol, Vol. pp. 1-5).

J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print
Shah D
J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print | PMID: 21235664
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Healthcare Utilization and Expenditures in Patients with Atrial Fibrillation Treated with Catheter Ablation.

Ladapo JA, David G, Gunnarsson CL, Hao SC, ... March JL, Reynolds MR
Catheter Ablation in AF Patients, Including Age 65+, Reduces Utilization. Aim: The aim was to estimate the impact of catheter ablation on short- and long-term healthcare utilization and expenditures among atrial fibrillation (AF) patients in general and Medicare populations. Methods: Data were analyzed from The MarketScan(®) Databases. MarketScan data contain deidentified patient-level records from employer-sponsored and public health insurance plans. Multivariable regression models for utilization and expenditures were built for all patients, with subanalyses performed for patients ≥65 years. Results were compared to preablation figures and reported for 5 time groups, based on duration of available postablation follow-up: 6-12 months; 12-18 months; 18-24 months; 24-30 months; and 30-36 months. Results: A total of 3,194 patients were identified who had undergone catheter ablation for treatment of AF, had continuous enrollment in the database 6 months prior to first ablation, and had at least 1-year follow-up postablation. Compared to the 6 months prior to ablation, there were significant reductions in the number of outpatient appointments, inpatient days, and emergency room visits in the total study population and in the subset ≥65 years. There was a statistically significant (P < 0.01) decrease in total healthcare expenditures across 4 of the 5 6-month time periods, with annual savings ranging from $3,300 to $9,200. For patients ≥65 years, annual savings ranged from $3,200 to $9,200. Drug utilization also significantly declined (P < 0.01), with average annual medication savings ranging from $670 to $890, and from $740 to $880 for patients ≥65 years. Conclusion: Catheter ablation for AF reduced healthcare utilization and expenditures up to 3 years postablation. This reduction was consistent, significant, and had implications for general and Medicare populations. (J Cardiovasc Electrophysiol, Vol. pp. 1-8).

J Cardiovasc Electrophysiol: 22 Jul 2011; epub ahead of print
Ladapo JA, David G, Gunnarsson CL, Hao SC, ... March JL, Reynolds MR
J Cardiovasc Electrophysiol: 22 Jul 2011; epub ahead of print | PMID: 21777324
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Abstract

LBBB Tachycardia: What is the Mechanism?

Nair KK, Namboodiri N, Banavalikar B, Valaparambil A, Thajudeen A, Tharakan J
A 55-year-old gentleman presented with recurrent episodes of palpitation and documented wide QRS tachycardia not reverted with intravenous adenosine and required electrical cardioversion. There was minimal preexcitation on surface electrocardiogram and transthoracic echocardiography demonstrated no evidence of structural heart disease. The electrophysiological study showed a normal AH interval of 94 ms and HV interval of 34 ms during sinus rhythm. Incremental atrial pacing from the lateral right atrium (RA) showed progressive preexcitation. Ventricular pacing from right ventricular (RV) apex showed decremental conduction and slightly eccentric atrial activation. Atrial burst pacing repeatedly induced wide QRS tachycardia of left bundle branch block morphology (LBBB) (Fig:1 & 2). During one of the occasions, the LBBB tachycardia showed spontaneous change in the tachycardia cycle length (TCL). What is the mechanism of the LBBB tachycardia? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 15 Jul 2016; epub ahead of print
Nair KK, Namboodiri N, Banavalikar B, Valaparambil A, Thajudeen A, Tharakan J
J Cardiovasc Electrophysiol: 15 Jul 2016; epub ahead of print | PMID: 27422697
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New Anticoagulants for Prevention of Stroke in Patients With Atrial Fibrillation.

Viles-Gonzalez JF, Fuster V, Halperin JL
New Anticoagulants in Atrial Fibrillation.  Atrial fibrillation (AF) is the most common cardiac rhythm disorder and a major risk factor for ischemic stroke. Antithrombotic therapy using vitamin K antagonists (VKA) is currently prescribed for prevention of ischemic stroke in patients with AF. A narrow therapeutic range and frequent food and drug interactions underly the need for regular monitoring of anticoagulation intensity and impairs the utility and safety of VKA, stimulating a quest for alternative anticoagulant agents. Recently developed anticoagulants include the direct thrombin inhibitor, dabigatran, and the factor Xa inhibitors rivaroxaban, apixaban, edoxaban, to name those in the most advanced stages of clinical development. This review focuses on advances in the development of novel antithrombotic agents to provide practical information to clinicians on the use of these new drugs in patients with AF. (J Cardiovasc Electrophysiol, Vol. pp. 1-8).

J Cardiovasc Electrophysiol: 14 Jun 2011; epub ahead of print
Viles-Gonzalez JF, Fuster V, Halperin JL
J Cardiovasc Electrophysiol: 14 Jun 2011; epub ahead of print | PMID: 21668558
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Abstract

Change of Heart: Altered Atrial Activation Following an Atrial Extrastimulus.

Selvaraj R, Satheesh S, Balachander J
An 11- year-old boy presented with frequent episodes of palpitations. He had documented adenosine sensitive narrow complex tachycardia during these episodes. Electrocardiogram (ECG) in sinus rhythm showed a positive delta wave in V1 and negative delta wave in leads I and aVL consistent with a left free wall accessory pathway (Fig. 1). During electrophysiology study, tachycardia was induced with ventricular burst pacing. This was a narrow complex, regular tachycardia with a cycle length (CL) of 310 ms, 1:1 ventriculo-atrial relationship and earliest atrial activation in the distal coronary sinus. Although a good His signal is not seen, the His catheter is in the anteroseptal region. Right ventricular overdrive pacing during tachycardia showed a V-A-V response. Figure 2 shows a single atrial extrastimulus introduced during the tachycardia. What is the response and what is the interpretation? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 29 Oct 2015; epub ahead of print
Selvaraj R, Satheesh S, Balachander J
J Cardiovasc Electrophysiol: 29 Oct 2015; epub ahead of print | PMID: 26515519
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Differences in Ventriculoatrial Intervals During Entrainment and Tachycardia: A Simpler Method for Distinguishing Paroxysmal Supraventricular Tachycardia With Long Ventriculoatrial Intervals.

González-Torrecilla E, Almendral J, García-Fernández FJ, Arias MA, ... Pachón M, Fernández-Avilés F
VA Intervals to Distinguish PSVT. Introduction: Usefulness of the interval between the last pacing stimulus and the last entrained atrial electrogram (SA) minus the tachycardia ventriculoatrial (VA) interval in the differential diagnosis of supraventricular tachycardias with long (>100 ms) VA intervals has not been prospectively studied in a large series of patients. Our objective was to assess the usefulness of the difference SA-VA in diagnosing the mechanism of those tachycardias in patients without preexcitation. The results were compared with those obtained using the corrected return cycle (postpacing interval-tachycardia cycle length-atrioventricular [AV] nodal delay). Methods and results: We included 314 consecutive patients with inducible sustained supraventricular tachycardias with VA intervals >100 ms undergoing an electrophysiologic study. Atrial tachycardias were excluded. Tachycardia entrainment was attempted through pacing trains from right ventricular apex. The SA-VA difference and the corrected return cycle were calculated for every patient. Electrophysiologic study revealed 82 atypical AV nodal reentrant tachycardias (AVNRT) and 237 AV reentrant tachycardias (AVRT) using septal (n = 91) or free-wall (n = 146) accessory pathways (APs). A SA-VA difference >110 ms identified an atypical AVNRT with sensitivity, specificity, positive and negative predictive values of 99%, 98%, 95%, and 99.5%, respectively. Similarly, these values were 88%, 83%, 77%, and 92% for SA-VA difference <50 ms in identifying AVRT through a septal versus free-wall AP. The SA-VA difference showed higher accuracy in septal AP identification than that obtained using the corrected return cycle. Conclusion: The difference SA-VA provides a simpler electrophysiologic maneuver that reliably differentiates atypical AVNRT from AVRT regardless of concealed AP location. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 09 Mar 2011; epub ahead of print
González-Torrecilla E, Almendral J, García-Fernández FJ, Arias MA, ... Pachón M, Fernández-Avilés F
J Cardiovasc Electrophysiol: 09 Mar 2011; epub ahead of print | PMID: 21385264
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Abstract

Positioning of Left Ventricular Pacing Lead Guided by Intracardiac Echocardiography With Vector Velocity Imaging During Cardiac Resynchronization Therapy Procedure.

Bai R, Biase LD, Mohanty P, Hesselson AB, ... Natale A, Tomassoni GF
LV Lead Positioning Guided by ICE With Vector Velocity Imaging. Introduction: Intraoperative modality for "real-time" left ventricular (LV) dyssynchrony quantification and optimal resynchronization is not established. This study determined the feasibility, safety, and efficacy of intracardiac echocardiography (ICE), coupled with vector velocity imaging (VVI), to evaluate LV dyssynchrony and to guide LV lead placement at the time of cardiac resynchronization therapy (CRT) implant. Methods: One hundred and four consecutive heart failure patients undergoing ICE-guided (Group 1, N = 50) or conventional (Group 2, N = 54) CRT implant were included in the study. For Group 1 patients, LV dyssynchrony and resynchronization were evaluated by VVI including visual algorithms and the maximum differences in time-to-peak (MD-TTP) radial strain. Based on the findings, the final LV lead site was determined and optimal resynchronization was achieved. CRT responders were defined using standard criteria 6 months after implantation. Results: Both groups underwent CRT implant with no complications. In Group 1, intraprocedural optimal resynchronization by VVI including visual algorithms and MD-TTP was a predictor discriminating CRT response with a sensitivity of 95% and specificity of 89%. Use of ICE/VVI increased number of and predicted CRT responders (82% in Group 1 vs 63% in Group 2; OR = 2.68, 95% CI 1.08-6.65, P = 0.03). Conclusion: ICE can be safely performed during CRT implantation. "Real-time" VVI appears to be helpful in determining the final LV lead position and pacing mode that allow better intraprocedural resynchronization. VVI-optimized acute resynchronization predicts CRT response and this approach is associated with higher number of CRT responders. (J Cardiovasc Electrophysiol, Vol. pp. 1-8).

J Cardiovasc Electrophysiol: 04 Apr 2011; epub ahead of print
Bai R, Biase LD, Mohanty P, Hesselson AB, ... Natale A, Tomassoni GF
J Cardiovasc Electrophysiol: 04 Apr 2011; epub ahead of print | PMID: 21457384
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Abstract

Remote Magnetic Navigation for Catheter Ablation in Patients With Congenital Heart Disease: A Review.

Roy K, Gomez-Pulido F, Ernst S
In patients with congenital heart disease, challenges to catheter-based arrhythmia interventions are unique and numerous given the complexity of the underlying defects, anatomic and surgical intervention variants including baffles, conduits, patches, and/or shunts. Remote magnetic navigation offers significant advantages in these cases that may present with limited vascular access or difficult access to the target cardiac chambers implicated by the previous surgical interventions. We reviewed the data available on the safety, feasibility, and effectiveness of magnetic navigation for the treatment of arrhythmia in congenital heart disease and discussed the specific challenges related to various congenital defects and repair with the potential advantages offered by magnetic navigation in these circumstances.

J Cardiovasc Electrophysiol: 11 Mar 2016; 27:S45-S56
Roy K, Gomez-Pulido F, Ernst S
J Cardiovasc Electrophysiol: 11 Mar 2016; 27:S45-S56 | PMID: 26969223
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Abstract

Effect of Limb Lead Electrodes Location on ECG and Localization of Idiopathic Outflow Tract Tachycardia: A Prospective Study.

Arya A, Huo Y, Frogner F, Wetzel U, ... Piorkowski C, Hindricks G
Role of ECG in Localization of OT-VT. Background: Different kinds of the surface ECG limb electrode positions may affect the limb lead vector and therefore the accuracy of the 12-lead ECG in localization of outflow tract ventricular tachycardia (OTVT). This study was intended to evaluate and compare the accuracy of the standard and the modified 12-lead ECG for localization of OTVT using the current published criteria. Methods and results: Twenty consecutive patients (10 men, mean age, 51.6 ± 13.4 years) with OT-VT were included. A standard ECG with the distal placement of the limb lead electrodes and a modified ECG with the limb electrodes placed on the torso were recorded during the OT-VT and were used for localization by 2 electrophysiologists who were blinded to the successful ablation site to compare the accuracy of the 2 ECGs. The R wave amplitude during OT-VT in lead I of the standard 12-lead ECG was significantly higher compared to the modified surface ECG (0.225 ± 0.145 mV vs 0.139 ± 0.111 mV, P = 0.032). The S wave in aVR during OT-VT was significantly more negative compared to the modified surface ECG (-0.682 ± 0.182 mV vs -0.527 ± 0.228 mV, P = 0.017). The rate of accurate localization of the successful ablation sites in the anterior versus posterior outflow tract by the 2 observers using standard ECG (70% and 80%) were higher compared to modified ECG (50% and 60%, P = 0.042). Conclusion: The R wave amplitude in lead I and the depth of the S wave amplitude in lead aVR of the standard surface ECG during OT-VT is significantly larger compared to the modified surface ECG. As the QRS morphology of the OT-VT is usually the first clue to the possible site of successful ablation, the standard 12-lead ECG should be used for more accurate localization of the origin of the OT-VT. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 21 Feb 2011; epub ahead of print
Arya A, Huo Y, Frogner F, Wetzel U, ... Piorkowski C, Hindricks G
J Cardiovasc Electrophysiol: 21 Feb 2011; epub ahead of print | PMID: 21332862
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Abstract

The Risk of Sudden Cardiac Death in Mitral Valve Prolapse: Are All Patients Created Equal?

Al-Khatib SM
Whether mitral valve prolapse (MVP) increases the risk of sudden cardiac death (SCD) has tantalized patients and clinicians for decades. This enigma is an important one as MVP is a common disorder that affects 2% to 3% of the general population and greater than 176 million people worldwide.(1) Many of the affected individuals are otherwise healthy and are diagnosed early in their lives, and many worry about their risks of death and complications. As clinicians, what should we tell these patients about their prognosis? After decades of investigation, we can tell them that MVP can be associated with significant mitral regurgitation, bacterial endocarditis, heart failure, and SCD.(1,2) While all of these complications can be detrimental, the risk of SCD is the most anxiety-provoking. So, what have we learned about the risk of SCD that could benefit patients? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 11 Jan 2016; epub ahead of print
Al-Khatib SM
J Cardiovasc Electrophysiol: 11 Jan 2016; epub ahead of print | PMID: 26756418
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Abstract

Phrenic Nerve Injury During Isolation of the Superior Vena Cava: Prevention Using Diaphragmatic Compound Motor Action Potentials. "Primum Nil Nocere."

Deneke T, Mügge A, Nentwich K, Halbfaß P
Phrenic nerve injury (PNI) is a major complication of cardiac ablation procedures leading to paralysis of the diaphragm. Anectodal reports on PNI after ablation of left- sided accessory pathways, right-sided atrial tachycardias and epicardial ablation of ventricular tachycardias exist, but it is more common in atrial fibrillation (AF) ablation. PNI is rare after isolation of the right-sided (mostly superior) pulmonary vein (PV) (up to 0.48%) (1) or isolation of the superior vena cava (SVC) (2.1%) (2) using radiofrequency energy. In contrast, it has been documented in up to 20% of PV isolation procedures in highly experienced centers using the cryoballoon generation 1 and 2 making this the most common complication among all AF ablation technologies (3,4). This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 02 Feb 2016; epub ahead of print
Deneke T, Mügge A, Nentwich K, Halbfaß P
J Cardiovasc Electrophysiol: 02 Feb 2016; epub ahead of print | PMID: 26840380
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Abstract

Transient Loss of Ventricular Pacing Capture Caused by Vagal Induced Ventricular Refractoriness: A Novel, Mechanism for Pacemaker Failure in Vaso-Vagal Syncope.

Malik V, Alasady M, Arnolda LF
A 48-year-old female who had frequent vasovagal syncope and a demonstrated cardio-inhibitory component (15 second asystole) underwent pacemaker implantation (Victory XL DR 5816, St Jude Medical) with Atrial (A; 1642T, 52cm) and Ventricular (V; 646T, 58cm) leads inserted via the subclavian vein with acceptable sensing (A; 1.2mV and V; 13.2 mV), threshold (A; 0.4V and V; 0.5V) and impedance (A; 664 Ω and V; 580 Ω). Pacing outputs were set at A; 2.4V and V; 2.3V with a programmed Atrio-Ventricular (AV) delay of 200ms (DDD). The next day she had a vasovagal attack during which there was loss of ventricular pacing capture (Figure 1). Pacemaker testing immediately after the event revealed stable impedance, sensing and appropriate capture at set outputs, including with an outstretched arm. A chest radiograph showed correct lead position. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 11 Mar 2016; epub ahead of print
Malik V, Alasady M, Arnolda LF
J Cardiovasc Electrophysiol: 11 Mar 2016; epub ahead of print | PMID: 26969794
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Abstract

Primary Prevention Implantable Cardioverter Defibrillator Recipients: The Need for Defibrillator Back-Up After an Event-Free First Battery Service-Life.

VAN Welsenes GH, VAN Rees JB, Thijssen J, Trines SA, ... Schalij MJ, Borleffs CJ
ICD Replacement After a Therapy-Free First Service-Life. Introduction: In primary prevention implantable cardioverter defibrillator (ICD) patients, the relatively low incidence of ventricular arrhythmias (VA) combined with the limited battery service-life potentially results in a large group of patients who have had no benefit of the ICD during first service-life. Data on the occurrence of VA after device replacement remain scarce. The purpose of this study was to give clinicians better insight in the dilemma whether or not to replace an ICD after an event-free first battery service-life. Methods and results: All patients treated with an ICD for primary prevention who had a replacement because of battery depletion and who did not receive appropriate therapy before device replacement were included in this analysis. Of 154 primary prevention ICD patients needing replacement because of battery depletion, 114 (74%) patients (mean age 61 ± 11 years, 80% male) had not received appropriate ICD therapy for VA. Follow-up was 71 ± 24 months after the initial implantation and 25 ± 21 months after device replacement. Following replacement, 3-year cumulative incidence of appropriate therapy in response to ventricular tachycardia or ventricular fibrillation was 14% (95% CI 5-22%). Conclusion: The majority of primary prevention ICD patients do not experience VA during first battery service-life. However, a substantial part of these patients does experience appropriate ICD therapy after replacement. (J Cardiovasc Electrophysiol, Vol. pp. 1-5).

J Cardiovasc Electrophysiol: 22 Jul 2011; epub ahead of print
VAN Welsenes GH, VAN Rees JB, Thijssen J, Trines SA, ... Schalij MJ, Borleffs CJ
J Cardiovasc Electrophysiol: 22 Jul 2011; epub ahead of print | PMID: 21777328
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Abstract

Arrhythmias in a Patient With Sarcoidosis.

Serra JL, Figueroa JA, Allende GE, Moreyra E
Arrhythmias in a Patient With Sarcoidosis. Sarcoidosis is a multisystemic granulomatous disease of unknown etiology; up to 27% of cases entail cardiac involvement. Conduction abnormalities and ventricular tachycardia are the most common arrhythmias and can cause sudden death. We describe a patient who developed cardiac sarcoidosis 9 years after undergoing surgery for neurosarcoidosis. He presented with 2:1 second-degree atrioventricular block. Ventricular tachycardia with 3 morphologies was induced by exercise stress test. A DDD pacer/implantable cardioverter defibrillator (ICD) was implanted, which prevented exercise-induced ventricular tachycardia in a follow-up stress test. Treatment with steroids was initiated. The AVB disappeared, and no further arrhythmias were documented at the 1-year follow-up. (J Cardiovasc Electrophysiol, Vol. pp. 1-4).

J Cardiovasc Electrophysiol: 14 Jun 2011; epub ahead of print
Serra JL, Figueroa JA, Allende GE, Moreyra E
J Cardiovasc Electrophysiol: 14 Jun 2011; epub ahead of print | PMID: 21668566
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Abstract

Electroanatomic Properties of the Pulmonary Veins: Slowed Conduction, Low Voltage and Altered Refractoriness in AF Patients.

Teh AW, Kistler PM, Lee G, Medi C, ... Sanders P, Kalman JM
Electroanatomic Properties of the Pulmonary Veins. Introduction: Rapid PV activity is critical in initiating and maintaining AF. The underlying substrate responsible for this remains uncertain. We sought to identify if patients with paroxysmal (PAF) and persistent atrial fibrillation (PeAF) have an abnormal substrate within the pulmonary veins (PVs). Methods and results: Thirty-nine patients with AF (21 PAF, 18 PeAF) were compared with 15 age-matched controls with left-sided accessory pathways (AVRT). High-density 3D electroanatomic maps of the PVs were created. PV voltage, conduction, PV muscle sleeve length, effective refractory periods (ERPs) of the PVs, posterior left atrium (PLA), left atrial appendage (LAA) and distal coronary sinus (CSd), and signal complexity were assessed. Compared with controls, the PVs of AF patients had (1) lower mean-voltage and a higher % low-voltage; (2) shorter PV muscle sleeves; (3) slower conduction; (4) shorter ERP; and (5) more prevalent complex signals. Compared with the PAF group, the PeAF group had (1) higher % low voltage; (2) slower conduction; and (3) more complex signals. In PAF patients, the PLA and LAA ERPs were longer than controls and the PV ERP was shorter than controls; in PeAF patients PLA and LAA ERPs were reduced, but to a lesser extent than in the PVs. AF induction occurred during PV ERP testing in both AF groups, but not controls. Conclusions: PAF and PeAF patients demonstrate electrical and electroanatomic remodeling of the PVs compared to control patients without prior AF. Some of these changes were more marked in PeAF. (J Cardiovasc Electrophysiol, Vol, pp. 1-9).

J Cardiovasc Electrophysiol: 03 Jun 2011; epub ahead of print
Teh AW, Kistler PM, Lee G, Medi C, ... Sanders P, Kalman JM
J Cardiovasc Electrophysiol: 03 Jun 2011; epub ahead of print | PMID: 21635610
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Abstract

Tachycardia Transition During Ablation of Persistent Atrial Fibrillation.

Arantes L, Klein GJ, Jaïs P, Lim KT, ... Clémenty J, Haïssaguerre M
Tachycardia Transition. Background: The "sequential ablation" strategy for persistent AF is aimed at progressive organization of AF until the rhythm converts to sinus rhythm or atrial tachycardia (AT). During ablation of an AT, apparently seamless transitions from one organized AT to another occur. The purpose of our study was to quantify the occurrence and the mechanism of this transition. Methods and results: Twenty-nine of 90 patients undergoing ablation for persistent AF had multiple AT during the procedure and constitute the study group. Thirty-nine direct transitions from one AT to another during ablation were observed classified in four types: type I (79.4%), i.e., a direct transition of a faster to a slower tachycardia without significant intervening pause; type II (7.69%)-transition after intervening ectopy or longer pause; type III (10.26%)-A slower AT accelerated; type IV (2.56%)-alteration of activation sequence but with no change on CL. Conclusions: Transition to a second AT occurs frequently in the midst of ablation of AT in persistent AF patients. This transition occurs most commonly abruptly within the range of a single cycle length of the original AT. This is best explained by a continuation of AT that was "present" simultaneously with the pretransition tachycardia, being "entrained" (for a reentrant tachycardia) or "overdriven" for an automatic focal tachycardia. The presence of multiple tachycardia mechanisms active simultaneously would be consistent with the eclectic pathophysiology of persistent AF. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 30 Nov 2010; epub ahead of print
Arantes L, Klein GJ, Jaïs P, Lim KT, ... Clémenty J, Haïssaguerre M
J Cardiovasc Electrophysiol: 30 Nov 2010; epub ahead of print | PMID: 21114705
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Abstract

Instantaneous Electrophysiological Changes Characterizing Achievement of Mitral Isthmus Linear Block.

Miyazaki S, Shah AJ, Jadidi AS, Scherr D, ... Jaïs P, Haïssaguerre M
Electrophysiological Change and Mitral Line Block. Background: Achievement of complete conduction block across left mitral isthmus (MI) is a challenging endpoint of linear lesion, and recognizing the precise moment of block is important during ongoing ablation. The objective of this study is to evaluate the changes in P wave morphology and local MI potential at the moment of block during ongoing radiofrequency (RF) application. Methods and results: We evaluated 69 patients (procedures) in whom successful MI linear conduction block was achieved during coronary sinus (CS) pacing. P wave morphology and/or local MI potential could be evaluated in 64 (93%) and 69 (100%) procedures, respectively. The achievement of MI block was associated with substantial instantaneous changes in 57/69 (82.6%) procedures. P wave morphology changed in 44 (64%) procedures with the change restricted to lateral leads in 39 (57%). Abrupt prolongation of local conduction delay from 106 ± 24 ms to 167 ± 39 ms (P < 0.0001) was observed on proximal bipole of ablation catheter in 34/69 (49.3%) procedures during ongoing RF application. In addition, prolongation of conduction delay was associated with significant change in the electrogram amplitude and polarity in 11 and 19 procedures, respectively. The substantial change in P wave morphology was not observed in any patients without achievement of complete block. Conclusions: The achievement of conduction block across MI line is associated with recognizable changes in the local MI electrograms and the P wave morphology especially in the lateral leads. These instantaneous critical changes may assist catheter ablation and indicate the requirement for prolonged RF application, if necessary. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 14 Jun 2011; epub ahead of print
Miyazaki S, Shah AJ, Jadidi AS, Scherr D, ... Jaïs P, Haïssaguerre M
J Cardiovasc Electrophysiol: 14 Jun 2011; epub ahead of print | PMID: 21668561
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Abstract

"Cardio-Neuromodulation" with a Multi-Electrode Irrigated Catheter A Potential New Approach for Patients with Cardio-Inhibitory Syncope.

Debruyne P
Syncope is frequently neurally mediated and can seriously affect quality of life. Different ablation strategies have been successfully performed. These approaches have not gained wide acceptance and are quite extensive and complex, exposing patients to significant risks. This article reports the case of a 16-year-old girl who was severely affected by frequent and prolonged episodes of syncope and was treated by tailored ablation of the anterior right ganglionated plexus with a multi-electrode irrigated catheter. She had fainted >30 times in the 5 years preceding treatment, experiencing approximately 10 severe episodes of syncope in the previous 12 months. After 3 minutes of ablation, the P-P interval was reduced by >400 ms. Syncope disappeared and the patient has remained completely asymptomatic over a follow-up of 22 months. The "reset" basal P-P interval has remained unchanged (follow-up electrocardiogram at 16 months). At 6 months, there was no residual heart rate activity <50 bpm. On 24-hour rhythm registration, P-P intervals ≥1,000 ms (corresponding to a heart rate of ≤60 bpm) were reduced by >16,000 beats. We believe that this case report is original for several reasons: the unusual clinical presentation; the unique structure targeted; the very limited ablation, implying much lower risks for the patient; the anatomical approach; and the different endpoint. This new "cardio-neuromodulation" approach could be useful for the treatment of patients with neurally mediated syncope. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 15 Jun 2016; epub ahead of print
Debruyne P
J Cardiovasc Electrophysiol: 15 Jun 2016; epub ahead of print | PMID: 27307200
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Sudden Cardiac Death Despite a Functional Cardioverter-Defibrillator: The Case for Early and Aggressive Therapy for Ventricular Tachycardia in Selected Patients.

Montgomery JA, Kanagasundram AN, Clair WK, Rottman JN, Crossley GH
We present three cases within 11 months at a single institution of sustained VT that fell below the programmed detection rate of the patients\' implantable cardioverter-defibrillators (ICDs), two of which continued until converting to an agonal VF that did not meet criteria for detection, and a third case that could not be successfully defibrillated after a prolonged period of VT. These episodes may be under-recognized due to the dependence of device diagnostic storage on programming and the post-mortem effort that is often required to review these events. Some patients, likely those with the most advanced heart failure, may not tolerate sustained ventricular tachycardia (VT) and may even die from ventricular arrhythmias without ever having a rhythm that meets detection criteria in a ventricular fibrillation (VF) zone. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 28 Oct 2015; epub ahead of print
Montgomery JA, Kanagasundram AN, Clair WK, Rottman JN, Crossley GH
J Cardiovasc Electrophysiol: 28 Oct 2015; epub ahead of print | PMID: 26511459
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Abstract

Remote Magnetic Navigation: A Focus on Catheter Ablation of Ventricular Arrhythmias.

Aagaard P, Natale A, Briceno D, Nakagawa H, ... Burkhardt JD, DI Biase L
VT ablation is based on percutaneous catheter insertion under fluoroscopic guidance to selectively destroy (i.e., ablate) myocardial tissue regions responsible for the initiation or propagation of ventricular arrhythmias. Although the last decade has witnessed a rapid evolution of ablation equipment and techniques, the control over catheter movement during manual ablation has remained largely unchanged. Moreover, the procedures are long, and require ergonomically unfavorable positions, which can lead to operator fatigue. In an attempt to overcome these constraints, several technical advancements, including remote magnetic navigation (RMN), have been developed. RMN utilizes a magnetic field to remotely manipulate specially designed soft-tip ablation catheters anywhere in the x, y, or z plane inside the patient\'s chest. RMN also facilitates titration of the contact force between the catheter and the myocardial tissue, which may reduce the risk of complications while ensuring adequate lesion formation. There are several non-randomized studies showing that RMN has similar efficacy to manual ablation, while complication rates and total radiation exposure appears to be lower. Although these data are promising, larger randomized studies are needed to prove that RMN is superior to manual ablation of VT.

J Cardiovasc Electrophysiol: 11 Mar 2016; 27:S38-S44
Aagaard P, Natale A, Briceno D, Nakagawa H, ... Burkhardt JD, DI Biase L
J Cardiovasc Electrophysiol: 11 Mar 2016; 27:S38-S44 | PMID: 26969222
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Abstract

Time- and Frequency-Domain Characteristics of Atrial Electrograms During Sinus Rhythm and Atrial Fibrillation.

Chang SH, Ulfarsson M, Chugh A, Yoshida K, ... Morady F, Oral H
Ablation and Spectral Characteristics of Fibrillation. Background: Complex fractionated atrial electrograms (CFAE) have been considered to be helpful during catheter ablation of atrial fibrillation (AF). The purpose of this study was to analyze the characteristics of CFAEs recorded during sinus rhythm (SR) and AF, and to determine their relationship to perpetuation of AF and clinical outcome. Methods and results: Antral pulmonary vein isolation (APVI) was performed in 34 consecutive patients (age = 59 ± 10 years) with paroxysmal AF who presented in SR. Time- and frequency-domain characteristics of electrograms recorded from the same sites in the coronary sinus (CS) were analyzed during SR and AF, before and during isoproterenol infusion. There was a modest correlation in fractionation index (FI: change in the direction of depolarization, r = 0.40, P = 0.001) and complexity index (CI: change in the polarity of depolarization, r = 0.41, P = 0.001), but not in the dominant frequency (DF) between SR and AF. There was no relationship between the DF and CI or FI during AF. Isoproterenol was associated with an increase in DF during AF (6.6 ± 0.9 vs 5.1 ± 0.6 Hz, P < 0.001) but had no effect on CI or FI (P = 0.6). A higher CI (58.3 ± 21.0/s vs 38.0 ± 21.0/s, P < 0.01), and FI (123.5 ± 44.8/s vs 75.6 ± 44.6/s, P < 0.01) during AF were associated with a lower likelihood of termination of AF during APVI and a higher probability of recurrent AF after ablation. Ratio of FI during AF to SR was also higher when AF persisted than terminated after APVI (29.7 ± 12.4 vs 19.1 ± 9.7, P = 0.002). However, time- or frequency-domain parameters during SR were not predictive of termination or clinical outcome. Conclusions: Structural and functional properties of the atrial myocardium during AF contribute to electrogram complexity, which may indicate the presence of extra-PV mechanisms of AF that are not eliminated by APVI. Mapping of complex electrograms in SR is not likely to be sufficient to identify drivers of AF. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 21 Feb 2011; epub ahead of print
Chang SH, Ulfarsson M, Chugh A, Yoshida K, ... Morady F, Oral H
J Cardiovasc Electrophysiol: 21 Feb 2011; epub ahead of print | PMID: 21332871
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Abstract

Is there a role for genetics in the prevention of sudden cardiac death?

Faragli A, Underwood K, Priori SG, Mazzanti A
The identification of patients at risk for sudden cardiac death (SCD) is fundamental for both acquired cardiovascular diseases (such as coronary artery diseases, CAD) and inherited arrhythmia syndromes (such as the long-QT Syndrome, LQTS). Genetics may play a role in both situations, although the potential to exploit this information to reduce the burden of SCD varies among these two groups. Concerning acquired cardiovascular diseases, which affect most of the general population, preliminary data suggest an association between genetics and the risk of dying suddenly. The maximal utility, instead, is reached in inherited arrhythmia syndromes, where the discovery of monogenic diseases such as LQTS tracked the way for the first genotype-phenotype correlations. The aim of this review is to provide a general overview focusing on the current genetic knowledge and on the present and future applicability for prevention in these two populations at risk for SCD. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 08 Jun 2016; epub ahead of print
Faragli A, Underwood K, Priori SG, Mazzanti A
J Cardiovasc Electrophysiol: 08 Jun 2016; epub ahead of print | PMID: 27279603
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Abstract

Left Atrial Stiffness Relates to Left Ventricular Diastolic Dysfunction and Recurrence After Pulmonary Vein Isolation for Atrial Fibrillation.

Machino-Ohtsuka T, Seo Y, Tada H, Ishizu T, ... Sekiguchi Y, Aonuma K
Left Atrial Stiffness and Atrial Fibrillation. Introduction: An increased left atrial (LA) stiffness reflects the structural remodeling and deterioration of the LA function. This study was designed to estimate LA stiffness by measuring a combination of the strain and LA pressure in patients undergoing pulmonary vein isolation (PVI) of atrial fibrillation (AF) and to evaluate the influence of the LA stiffness on the cardiac function, serum markers, and recurrence of AF after PVI. Methods: In 155 consecutive patients with AF, the brain natriuretic peptide (BNP) and aminoterminal procollagen type III propeptide (PIIIP) plasma levels were measured before the PVI. The difference between the minimum and maximum LA systolic pressures was directly measured by a transseptal puncture. The ratio of the difference in the LA pressures to the peak systolic LA strain evaluated by speckle-tracking echocardiography was used as an index of the LA stiffness. Results: The calculated LA stiffness index was related to the BNP level (r(s) = 0.444, P < 0.001), E/E\' ratio (r(s) = 0.444, P < 0.001), LA volume index (r(s) = 0.370, P < 0.001), and PIIIP level (r(s) = 0.305, P = 0.002). During a mean follow-up period of 33.8 ± 12.2 months, 45 patients (29%) presented with AF recurrences. A Cox proportional hazard regression analysis showed the LA stiffness index was an independent predictor of recurrence of AF (HR 2.88; 95% CI 1.75 to 4.73, P < 0.001). Conclusions: In patients with AF, the LA stiffness index is related to left ventricular diastolic dysfunction, LA dilatation, and collagen synthesis and may predict AF recurrences after PVI. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 04 Apr 2011; epub ahead of print
Machino-Ohtsuka T, Seo Y, Tada H, Ishizu T, ... Sekiguchi Y, Aonuma K
J Cardiovasc Electrophysiol: 04 Apr 2011; epub ahead of print | PMID: 21457382
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Pretreatment of BAPTA-AM Suppresses the Genesis of Repetitive Endocardial Focal Discharges and Pacing-Induced Ventricular Arrhythmia During Global Ischemia.

Wu TJ, Lin SF, Hsieh YC, Lin TC, Lin JC, Ting CT
BAPTA-AM and Repetitive Endocardial Focal Discharges. Introduction: In isolated rabbit hearts, repetitive endocardial focal discharges (REFDs) were consistently observed during ventricular fibrillation (VF) with prolonged (>5 minutes) global ischemia (GI). We hypothesized that BAPTA-AM, a calcium chelator, can suppress these REFDs. Methods and results: Using a two-camera optical mapping system, we simultaneously mapped endocardial (left ventricle, LV) and epicardial (both ventricles) activations during ventricular arrhythmia with GI. In 5 hearts (protocol I), we infused Tyrode\'s solution (no BAPTA-AM) for ≥30 minutes before the onset of no-flow GI. In 7 additional hearts (protocol II), BAPTA-AM (20 μmol/L) was infused for ≥30 minutes before the initiation of GI. In protocol I, sustained VF (>30 seconds) was successfully induced in all 5 hearts with prolonged GI. REFDs were present in >85 % of recording time. In protocol II, however, ventricular arrhythmia was not inducible and REFDs were not observed after 5-minute GI in 5 hearts. Effects of BAPTA-AM on intracellular calcium (Ca(i) ) at the LV endocardium were also evaluated in 5 hearts (protocol III) using dual Ca(i) /membrane potential mapping. GI, both without and with BAPTA-AM pretreatment, caused a decrease of Ca(i) amplitude during S(1) pacing. However, this effect was more pronounced in the hearts with BAPTA-AM pretreatment (P < 0.001). GI, without BAPTA-AM pretreatment, caused broadening of Ca(i) transient. In contrast, GI, with BAPTA-AM pretreatment, caused narrowing of Ca(i) transient. Conclusions: BAPTA-AM pretreatment attenuates Ca(i) transient, suppressing the genesis of REFDs and pacing-induced ventricular arrhythmia during GI. These findings support the notion that Ca(i) dynamics is important in the maintenance of REFDs. (J Cardiovasc Electrophysiol, Vol. pp. 1-9).

J Cardiovasc Electrophysiol: 14 Apr 2011; epub ahead of print
Wu TJ, Lin SF, Hsieh YC, Lin TC, Lin JC, Ting CT
J Cardiovasc Electrophysiol: 14 Apr 2011; epub ahead of print | PMID: 21489030
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Identifying the Relationship Between the Non-PV Triggers and the Critical CFAE Sites Post-PVAI to Curtail the Extent of Atrial Ablation in Longstanding Persistent AF.

Elayi CS, DI Biase L, Bai R, Burkhardt JD, ... Beheiry S, Natale A
Relationship Between the Non-PV Triggers and the Critical CFAE Sites. Background: Complex fractionated atrial electrograms (CFAE) ablation has been performed in addition to pulmonary veins (PV) isolation to increase the success rate of atrial fibrillation (AF) ablation in patients with longstanding (LS) persistent AF. The mechanism underlying the clinical benefit of CFAE ablation remains, however, poorly understood. Objective: We compared the impact of CFAE ablation on the prevalence of non-PV atrial triggers inducing AF in 2 groups of patients with LS persistent AF. One group underwent PVAI alone, and the other group underwent PVAI plus CFAE ablation. In addition, we correlated the site of non-PV triggers with the presence of CFAE. Methods: A total of 98 consecutive patients with symptomatic drug refractory LS persistent AF presenting for ablation had a preablation electroanatomic CFAE map. Patients randomized to either isolation of the PVs and posterior wall (PVAI) (group I, n = 48 pts) or PVAI and biatrial ablation of CFAEs (group II, 50 pts). After ablation, infusion of isoproterenol up to 30 mcg/min was given to reveal non PV foci inducing AF. Those foci were mapped and correlated with CFAE regions and ablated. Results: A total of 19 patients (76%) with PV foci inducing AF were associated with either stable or transient CFAE after PVAI, respectively, in 12 patients (48%) and 7 patients (28%). A total of 20 (42%) non-PV triggers were observed in group I versus 5 (10%) in group II (P < 0.001) in 18 and 5 patients, respectively. After a mean f/u of 17.2 ± 5.2 months, 33 (69%) patients in group I and 36 (72%) patients in group II were in SR (P = NS). Conclusion: Non-PV triggers inducing AF post-PVAI were associated with the presence of stable or transient CFAE in 48% and 28% of cases, respectively, in LS persistent AF. CFAE ablation after PVAI was associated with a significantly higher elimination of those non-PV triggers. This suggests that at least part of the beneficial effect achieved by CFAE ablation reflects elimination of non-PV AF triggers. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 22 Jun 2011; epub ahead of print
Elayi CS, DI Biase L, Bai R, Burkhardt JD, ... Beheiry S, Natale A
J Cardiovasc Electrophysiol: 22 Jun 2011; epub ahead of print | PMID: 21692897
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Abstract

Narrow QRS tachycardia with RR alternans and 2:1 VA relation.

Nair KK, Namboodiri N, Thajudeen A, Patel N, Valaparambil A, Tharakan J
A 50-year-old female underwent electrophysiology study for paroxysmal palpitation. Panel A represents surface electrocardiogram showing narrow QRS tachycardia with RR alternans and 2:1 VA relation. Panel B represents intracardiac electrogram showing AV nodal reentrant tachycardia with alternation between two antegrade conduction times with retrograde conduction to atrium occurring only after longer antegrade conduction. The underlying morphological substrate behind this interesting phenomenon is not known. There may be potential mechanisms possible like antegrade conduction alternating between anatomically or functionally distinct antegrade pathways and retrograde conduction to atrium occurring only after longer antegrade conduction probably due to longer preceding HH interval or two antegrade conducting pathways with separate turn around points with one not retrogradely conducting to the atrium or multiple potential exits of the circuit with one not retrogradely conducting to the atrium. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 13 Jan 2016; epub ahead of print
Nair KK, Namboodiri N, Thajudeen A, Patel N, Valaparambil A, Tharakan J
J Cardiovasc Electrophysiol: 13 Jan 2016; epub ahead of print | PMID: 26766348
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Abstract

Voltage-based ablation: The growing evidence for the role of individually tailored substrate modification for atrial fibrillation.

Rolf S, Dagres N, Hindricks G
Catheter ablation has become an established treatment for patients with atrial fibrillation (AF). Trigger elimination by pulmonary vein (PV) isolation represents the cornerstone of ablation strategies. Success rates after PV isolation (PVI) differ depending on the form of the arrhythmia, generally being higher in paroxysmal than in persistent AF. This difference may be explained by the presence and extent of structural atrio-myocardial disease, which is often associated with more chronic forms of the arrhythmia. However, the association between the substrate (i.e., atrio-myocardial disease) and the clinical and electrocardiographic AF phenotype, particularly the potential causal relation between substrate and arrhythmia presentation, is complex and currently under intense debate.(1) The introduction of the concept of a fibrotic atrial cardiomyopathy as a primary disease driving AF has great impact both on pathophysiological understanding of AF and subsequent treatment strategies.

J Cardiovasc Electrophysiol: 02 Nov 2015; epub ahead of print
Rolf S, Dagres N, Hindricks G
J Cardiovasc Electrophysiol: 02 Nov 2015; epub ahead of print | PMID: 26527227
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Abstract

Pharmacological Inhibition of the hERG Potassium Channel Is Modulated by Extracellular But Not Intracellular Acidosis.

DU CY, El Harchi A, Zhang YH, Orchard CH, Hancox JC
Acidosis and hERG K(+) Channel Pharmacology.  Introduction: Human Ether-à-go-go related gene (hERG) is responsible for channels that mediate the rapid delayed rectifier K(+) channel current (I(Kr) ), which participates in repolarization of the ventricles and is a target for some antiarrhythmic drugs. Acidosis occurs in the heart in some pathological situations and can modify the function and responses to drugs of ion channels. The aim of this study was to determine the effects of extracellular and intracellular acidosis on the potency of hERG channel current (I(hERG) ) inhibition by the antiarrhythmic agents dofetilide, flecainide, and amiodarone at 37 °C. Methods and results: Whole-cell patch-clamp recordings of I(hERG) were made at 37 °C from hERG-expressing Human Embryonic Kidney (HEK293) cells. Half-maximal inhibitory concentration (IC(50) ) values for I(hERG) tail inhibition at -40 mV following depolarizing commands to +20 mV were significantly higher at external pH 6.3 than at pH 7.4 for both flecainide and dofetilide, but not for amiodarone. Lowering pipette pH from 7.2 to 6.3 altered neither I(hERG) kinetics nor the extent of observed I(hERG) blockade by any of these drugs. Conclusion: Conditions leading to localized extracellular acidosis may facilitate heterogeneity of action of dofetilide and flecainide, but not amiodarone via modification of hERG channel blockade. Such effects depend on the external pH change rather than intracellular acidification. (J Cardiovasc Electrophysiol, Vol. pp. 1-8).

J Cardiovasc Electrophysiol: 14 Apr 2011; epub ahead of print
DU CY, El Harchi A, Zhang YH, Orchard CH, Hancox JC
J Cardiovasc Electrophysiol: 14 Apr 2011; epub ahead of print | PMID: 21489024
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Abstract

The Electroanatomic Mechanisms of Atrial Tachycardia in Patients with Tetralogy of Fallot and Double Outlet Right Ventricle.

Mah DY, Alexander ME, Cecchin F, Walsh EP, Triedman JK
Atrial Tachycardia in Tetralogy of Fallot and DORV. Background: Atrial tachycardias (AT) are common after palliation or repair of congenital heart disease. The electroanatomic mechanism of AT in postoperative tetralogy of Fallot (TOF) and double outlet right ventricle (DORV) patients has not been fully explored. Methods and results: Retrospective analysis of TOF or DORV patients was performed in the electrophysiology (EP) lab from January 1997 to March 2010. Sustained ATs were mapped using the Carto system (Biosense Webster, Diamond Bar, CA, USA). Fifty-eight patients were identified with 82 EP studies performed and 127 ATs identified. The first EP study for AT was performed at a median age of 35 years (2-58 years). Ninety-five IART circuits were identified, 5 in a figure-of-8 pattern. There were 13 focal ATs, 4 ectopic ATs, and 15 presentations of atrial fibrillation (AF). The cavotricuspid isthmus (CTI) was the critical area for ablation in the majority of TOF and DORV patients (53%). The CTI, along with the lateral RA wall, made up 85% of IART circuits. Excluding AF, the acute success rate for ablation was 90%. Of the 58 patients, 20 had additional ablation attempts, 19 within 3 years of their first ablation. Conclusion: The CTI and lateral RA wall are critical corridors of conduction in 85% of IART circuits in TOF and DORV patients. The acute success rate for AT ablations is high, but a substantial number of patients have required additional ablation procedures. Recurrences may be reduced if both the CTI and lateral RA wall are targeted and blocked, even if the mapped circuit points only to 1 region. (J Cardiovasc Electrophysiol, Vol. pp. 1-5).

J Cardiovasc Electrophysiol: 04 May 2011; epub ahead of print
Mah DY, Alexander ME, Cecchin F, Walsh EP, Triedman JK
J Cardiovasc Electrophysiol: 04 May 2011; epub ahead of print | PMID: 21539636
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Abstract

Predicting Hyperresponse Among Pacemaker-Dependent Nonischemic Cardiomyopathy Patients Upgraded to Cardiac Resynchronization.

Adelstein E, Schwartzman D, Gorcsan J, Saba S
Resynchronizing Pacemaker-Dependent Patients. Introduction: Right ventricular (RV) pacing engenders left ventricular (LV) dyssynchrony and may diminish LV systolic function, promote adverse cardiac remodeling, and foster heart failure (HF). This process may be reversible in some pacemaker-dependent patients upgraded to cardiac resynchronization therapy (CRT). We examined the clinical characteristics of pacemaker-dependent patients who exhibit hyperresponse (i.e., normalization of LV function) with CRT upgrade. Methods and Results : We identified 51 chronically RV-paced patients with no coronary artery disease, LV ejection fraction (EF) ≤ 35%, and severe HF symptoms who were upgraded to CRT-defibrillators (CRT-D). Echocardiograms were performed before and ≥6 months after CRT. Patients with follow-up LVEF ≥ 50% were deemed hyperresponders. Clinical outcomes of death, cardiac transplant, mechanical circulatory support, and HF hospitalizations were assessed. Fifteen patients were CRT hyperresponders; all demonstrated ≥15% relative LV end-systolic volume decrease. Hyperresponders had smaller baseline LV dimensions and shorter known cardiomyopathy duration than nonhyperresponders (P < 0.01). The best predictors of hyperresponse using receiver operating characteristic analysis were LV end-systolic dimension <48 mm (area under the curve [AUC] 0.92, P < 0.001), LV end-diastolic dimension <58 mm (AUC 0.86, P < 0.001), and cardiomyopathy duration <24 months (AUC 0.82, P < 0.001). No hyperresponders died, received a cardiac transplant, or required mechanical circulatory support during 42 ± 22 months follow-up, whereas 5 nonhyperresponders died, 2 underwent transplant, and 1 required an assist device (log rank P = 0.049). Conclusion : Among chronically RV paced patients who are upgraded to CRT-D, smaller baseline LV dimensions and shorter known cardiomyopathy duration predict hyperresponse. Hyperresponders have excellent long-term survival. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 21 Feb 2011; epub ahead of print
Adelstein E, Schwartzman D, Gorcsan J, Saba S
J Cardiovasc Electrophysiol: 21 Feb 2011; epub ahead of print | PMID: 21332868
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Abstract

Low-Level Right Vagal Stimulation: Anticholinergic and Antiadrenergic Effects.

Sha Y, Scherlag BJ, Yu L, Sheng X, ... Lazzara R, Po SS
Right Vagal Stimulation Suppresses Atrial Fibrillation. Introduction: We sought to extend the use of low-level vagal stimulation by applying it only to the right vagus nerve (LL-RVS) to suppress atrial fibrillation (AF). Methods: In 10 pentobarbital anesthetized dogs, LL-RVS (20 Hz, 0.1 ms pulse width) was delivered to the right vagal trunk via wire electrodes at voltages 50% below that which slowed the sinus rate (SR) or atrio-ventricular conduction. Electrode catheters were sutured at multiple atrial and pulmonary vein (PV) sites to record electrograms. LL-RVS continued for 3 hours. At the end of each hour, 40 ms of high-frequency stimulation (HFS; 100 Hz, 0.01 ms pulse width) was delivered 2 ms after atrial pacing (during the refractory period) to determine the AF threshold (AF-TH) at each site. Other electrodes were attached to the superior left ganglionated plexi (SLGP) and right stellate ganglion (RSG) so that HFS (20 Hz, 0.1 ms pulse width) to these sites induced SR slowing and acceleration, respectively. Microelectrodes inserted into the anterior right ganglionated plexi (ARGP) recorded neural activity. Results: (1) Three hours of LL-RVS induced a progressive increase in AF-TH at all sites (all P < 0.05). (2) The SR slowing and acceleration response induced by SLGP and RSG stimulation, respectively, was blunted by LL-RVS. (3) The frequency and amplitude of the neural activity recorded from the ARGP were markedly inhibited by LL-RVS. Conclusions: LL-RVS suppressed AF inducibility and the chronotropic responses to parasympathetic and sympathetic stimulation. Inhibition of neural activity in the GP may be a mechanism underlying these results. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 14 Apr 2011; epub ahead of print
Sha Y, Scherlag BJ, Yu L, Sheng X, ... Lazzara R, Po SS
J Cardiovasc Electrophysiol: 14 Apr 2011; epub ahead of print | PMID: 21489033
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Abstract

Histogram Analysis: A Novel Method to Detect and Differentiate Fractionated Electrograms During Atrial Fibrillation.

El Haddad M, Houben R, Claessens T, Tavernier R, Stroobandt R, Duytschaever M
Histogram Analysis for CFAE Detection. Introduction: Complex fractionated atrial electrograms (CFAEs) might identify the critical substrate maintaining AF. We developed a method based upon histogram analysis of interpeak intervals (IPIs) to automatically quantify fractionation and differentiate between subtypes of CFAEs. Methods: Two experts classified 1,681 fibrillatory electrograms recorded in 13 patients with persistent AF into 3 categories (gold standard): normal electrograms, discontinuous CFAEs, or continuous CFAEs. Histogram analysis of IPI was performed to calculate the P5, P50, P95, and the mean of IPIs, in addition to the total number of IPI (N(Total) ), and the number of IPI within predetermined ranges: 10-60 (N(Short) ), 60-120 (N(Intermediate) ), and >120 ms (N(Long) ). Results: P50 and N(Long) were higher in the normal electrograms compared to the other 2 categories (P < 0.001). N(Intermediate) was higher in the discontinuous CFAE category compared to the other 2 categories. P95, mean IPI, N(Total) , and N(Short) were all significantly different among the 3 categories (P < 0.001) and correlated with the degree of fractionation (r =-0.52, -0.55, 0.68, and 0.67, respectively). Receiver operating characteristic (ROC) curves showed good diagnostic accuracy (area under curve, AUC > 0.8) of P50 and N(Long) to detect normal electrograms. An algorithm using N(Intermediate) showed good diagnostic accuracy (AUC > 0.7) to detect discontinuous CFAEs, whereas P95, mean, N(Total) , and N(Short) all revealed high diagnostic accuracy (AUC > 0.85) to detect continuous CFAEs. This was confirmed in a prospective data set. Conclusions: Histogram analysis of IPI can differentiate between normal electrograms, discontinuous and continuous fractionated electrograms. This method might be used to standardize and optimize ablation strategies in AF. (J Cardiovasc Electrophysiol, Vol. pp. 1-10).

J Cardiovasc Electrophysiol: 03 Feb 2011; epub ahead of print
El Haddad M, Houben R, Claessens T, Tavernier R, Stroobandt R, Duytschaever M
J Cardiovasc Electrophysiol: 03 Feb 2011; epub ahead of print | PMID: 21288281
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Cavotricuspid Isthmus Catheter Ablation Without the Use of Fluoroscopy as a First-Line Treatment.

Alvarez M, Tercedor L, Herrera N, Muñoz L, ... Peñas R, Melgares R
Cavotricuspid Isthmus Ablation Without Fluoroscopy. Introduction and Objectives: The use of intracardiac navigation systems has enabled a significant reduction of the radiation dose in the majority of ablation procedures. The purpose of this study is to evaluate the feasibility and safety of cavotricuspid isthmus ablation without the use of fluoroscopy as a first-line treatment. Methods and results: An observational study without a control group in patients referred for treatment of common atrial flutter. In all of the procedures, Ensite-NavX™ was the only guidance system used to visualize the catheters. One or two diagnostic catheters and a cooled-tip ablation catheter were used in each procedure. Bidirectional cavotricuspid isthmus block was considered to indicate a successful procedure. Eighty-three ablation procedures were performed in 80 patients (82.5% men, 61 ± 10 years of age). The procedure was repeated in 3 patients (3.75%) due to flutter recurrence. Success was obtained in 98.8% of the procedures; in 1 patient it was necessary to implant a pacemaker for sinus node dysfunction and 4 patients experienced minor complications. In 75 procedures (90.4%), fluoroscopy was not required. Visualization of the diagnostic catheters was the most common reason for using fluoroscopy. The time required to perform the ablation procedure was similar to that published in other series. Conclusions: Cavotricuspid isthmus ablation using a nonfluoroscopic thre-dimensional (3D) navigation system is effective and safe. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 30 Nov 2010; epub ahead of print
Alvarez M, Tercedor L, Herrera N, Muñoz L, ... Peñas R, Melgares R
J Cardiovasc Electrophysiol: 30 Nov 2010; epub ahead of print | PMID: 21114703
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Abstract

Relationship of Abnormal Heart Rate Turbulence and Elevated CRP to Cardiac Mortality in Low, Intermediate, and High-Risk Older Adults.

Stein PK, Barzilay JI
HRT and CRP for Mortality Risk in Elderly. Introduction: We examined whether heart rate turbulence (HRT) and C-reactive protein (CRP) add to traditional risk factors for cardiac mortality in older adults at low, intermediate, and high risk. Methods and results: One thousand two hundred and seventy-two individuals, age ≥65 years, with 24-hour Holter recordings were studied. HRT, which quantifies heart rate response to ventricular premature contractions, was categorized as: both turbulence onset (TO) and turbulence slope (TS) normal; TO abnormal; TS abnormal; or both abnormal. Independent risks for cardiac mortality associated with HRT or, for comparison, elevated CRP (>3.0 mg/L), were calculated using Cox regression analysis adjusted for traditional cardiovascular disease risk factors and stratified by the presence of no, isolated subclinical (i.e., intermediate risk) or clinical cardiovascular disease. Having TS + TO abnormal compared to both normal was associated with cardiac mortality in the low-risk group [HR 7.9, 95% confidence interval (CI) 2.8-22.5, (P < 0.001)]. In the high and intermediate risk groups, abnormal TS and TS + TO ([HR 2.2, 95% CI 1.5-4.0, P = 0.016] and [HR 2.7, 95% CI 1.2-5.9, P = 0.012]), respectively, were also significantly associated with cardiac mortality. In contrast, elevated CRP was associated with increased cardiac mortality risk only in low-risk individuals [HR 2.5, 95% CI 1.3-5.1, P = 0.009]. Among low risk, the c-statistic was 0.706 for the base model, 0.725 for the base model with CRP, and 0.767 for the base model with HRT. Conclusions: Abnormal HRT independently adds to risk stratification of low, intermediate and high-risk individuals, but HRT and CRP appear to both add to stratification of those considered low risk. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 07 Dec 2010; epub ahead of print
Stein PK, Barzilay JI
J Cardiovasc Electrophysiol: 07 Dec 2010; epub ahead of print | PMID: 21134026
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Deep Sedation for Catheter Ablation of Atrial Fibrillation: A Prospective Study in 650 Consecutive Patients.

Kottkamp H, Hindricks G, Eitel C, Müller K, ... Piorkowski C, Dagres N
Deep Sedation for Catheter Ablation of AF. Introduction: Catheter ablation of atrial fibrillation (AF) is a highly invasive and relatively long-lasting procedure with specific requirements for patient sedation. The feasibility and safety of deep sedation is described in a prospective study of 650 consecutive patients. Methods: Sedation was initiated with an intravenous (iv) bolus of midazolam, and analgesia with an iv fentanyl bolus. After an iv propofol bolus, maintenance of sedation was achieved with continuous iv administration of propofol with a guide dose of 5 mg per kg per hour. Heart rate, invasive arterial blood pressure, and oxygenation were continuously monitored. The administration of sedation and analgesia medication were performed by a nurse under the supervision and instructions of the electrophysiologist. Results: The mean dose of the initial midazolam bolus was 2.4 ± 0.7 mg and of the initial propofol bolus 32 ± 11 mg. The beginning dose of continuous propofol infusion was 352 ± 66 mg/h; titration to the desired effect of deep sedation required adjustment on an average of 3.8 ± 2.6 times leading to a maintenance dose of continuous propofol infusion of 399 ± 99 mg/h. No major sedation-related complications were observed. Endotracheal intubation was necessary in none of the patients. Heart rate, invasive arterial blood pressure, and oxygenation remained stable during sedation. Conclusion: Deep sedation for catheter ablation of AF is feasible and safe. Especially, the goal of keeping the patient in deep sedation while maintaining spontaneous ventilation and cardiovascular hemodynamic stability was accomplished. Endotracheal intubation or consultation of an anesthesiologist was not necessary in any patient. (J Cardiovasc Electrophysiol, Vol. pp. 1-5).

J Cardiovasc Electrophysiol: 22 Jun 2011; epub ahead of print
Kottkamp H, Hindricks G, Eitel C, Müller K, ... Piorkowski C, Dagres N
J Cardiovasc Electrophysiol: 22 Jun 2011; epub ahead of print | PMID: 21692895
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Renal Denervation for Treatment of Cardiac Arrhythmias: State of the Art and Future Directions.

Kosiuk J, Hilbert S, Pokushalov E, Hindricks G, Steinberg JS, Bollmann A
It has now been more than a quarter of a century since modulation of the sympathetic nervous system was proposed for the treatment of cardiac arrhythmias of different origins. But it has also been some time since some of the early surgical attempts have been abandoned. With the development of ablation techniques, however, new approaches and targets have been recently introduced that have revolutionized our way of thinking about sympathetic modulation. Renal nerve ablation technology is now being successfully used for the treatment of resistant hypertension, but the indication spectrum might broaden and new therapeutic options might arise in the near future. This review focuses on the possible impact of renal sympathetic system modulation on cardiac arrhythmias, the current evidence supporting this approach, and the ongoing trials of this method in electrophysiological laboratories. We will discuss the potential roles that sympathetic modulation may play in the future. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 17 Sep 2014; epub ahead of print
Kosiuk J, Hilbert S, Pokushalov E, Hindricks G, Steinberg JS, Bollmann A
J Cardiovasc Electrophysiol: 17 Sep 2014; epub ahead of print | PMID: 25231911
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Pulmonary Vein Stenosis after Cryoablation Using 28-mm Second-Generation Balloon.

Miyazaki S, Ichihara N, Iesaka Y
A 63-year-old man with drug-resistant paroxysmal atrial fibrillation (AF) was referred to our center for catheter ablation. He had no structural heart disease, and showed three right pulmonary veins (PVs) on pre-procedural cardiac computed tomography (Fig. 1A). The starting rhythm was sinus rhythm and the procedure was performed under moderate sedation with dexmetridine. A 28-mm second generation cryoballoon (Medtronic, Inc, Minneapolis, MN) was positioned at the ostium of right superior PV (RSPV), and the vein was occluded on venography at the position (Fig. 1B). The application was terminated 90 seconds after the start of the application due to the decrease in right phrenic compound motor action potential amplitude (minimal temperature -47℃), which recovered later. A 180 seconds of bonus burn was added for RSPV, and the other 3 PVs were successfully isolated by one cryoballoon application. The patient underwent second ablation procedure one month after the procedure because recurrent incessant AF resulted in heart failure. No PV reconnection was observed except in the RSPV; however, significant PV stenosis was observed at RSPV on venography (Fig. 1C, arrow). This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 15 Dec 2014; epub ahead of print
Miyazaki S, Ichihara N, Iesaka Y
J Cardiovasc Electrophysiol: 15 Dec 2014; epub ahead of print | PMID: 25511425
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β-Blockers Protect Against Dispersion of Repolarization During Exercise in Congenital Long-QT Syndrome Type 1.

Gemma LW, Ward GM, Dettmer MM, Ball JL, ... Doria DN, Kaufman ES
Dispersion of Repolarization in LQT1. Introduction:β-Blocker therapy reduces syncope and sudden death in long-QT syndrome type 1 (LQT1), but the mechanism of protection is incompletely understood. This study tested the hypothesis that β-blockade reduces QT prolongation and dispersion of repolarization, measured as the T peak-to-end interval (T(pe) ), during exercise and recovery in LQT1 patients. Methods and results: QT and T(pe) were measured in 10 LQT1 patients (33 ± 13 years) and 35 normal subjects (32 ± 12 years) during exercise tests on and off β-blockade. In LQT1 patients, β-blockade reduced QT (391 ± 25 milliseconds vs 375 ± 26 milliseconds, P = 0.04 during exercise; 419 ± 41 milliseconds vs 391 ± 39 milliseconds, P = 0.02 during recovery) and markedly reduced T(pe) (91 ± 26 milliseconds vs 67 ± 19 milliseconds, P = 0.03 during exercise; 103 ± 26 milliseconds vs 78 ± 11 milliseconds, P = 0.02 during recovery). In contrast, in normal subjects, β-blockade had no effect on QT (320 ± 17 milliseconds vs 317 ± 16 milliseconds, P = 0.29 during exercise; 317 ± 13 milliseconds vs 315 ± 14 milliseconds, P = 0.15 during recovery) and mildly reduced T(pe) (69 ± 13 milliseconds vs 61 ± 11 milliseconds, P = 0.01 during exercise; 77 ± 19 milliseconds vs. 68 ± 14 milliseconds, P < 0.001 during recovery). Conclusion: In LQT1 patients, β-blockers reduced QT and T(pe) during exercise and recovery, supporting the theory that β-blocker therapy protects LQT1 patients by reducing dispersion of repolarization during exercise and recovery. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 03 Jun 2011; epub ahead of print
Gemma LW, Ward GM, Dettmer MM, Ball JL, ... Doria DN, Kaufman ES
J Cardiovasc Electrophysiol: 03 Jun 2011; epub ahead of print | PMID: 21635612
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The long-QT syndrome and exercise practice: The never-ending debate.

Mascia G, Arbelo E, Solimene F, Giaccardi M, Brugada R, Brugada J
Today, understanding the true risk of adverse events in long-QT syndrome (LQTS) populations may be extremely complex and potentially dependent on many factors such as the affected gene, mutation location, degree of QTc prolongation, age, sex, and other yet unknown factors. In this context, risk stratification by genotype in LQTS patients has been extremely difficult, also during exercise practice, especially due to the lack of studies which would lead to a better understanding of the natural history of each mutation and its impact upon athletes. The creation of individualized guidelines for sport participation is a goal yet to be achieved not only due to the complexity of genotype effect on the phenotype in this patient population, but also due to penetrance in genotype-positive patients. This paper summarizes current knowledge and raises questions concerning the difficult relationship between exercise practice and LQTS. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 01 Jan 2018; epub ahead of print
Mascia G, Arbelo E, Solimene F, Giaccardi M, Brugada R, Brugada J
J Cardiovasc Electrophysiol: 01 Jan 2018; epub ahead of print | PMID: 29292852
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A Strategy of Rapid Cardioversion Minimizes the Significance of Early Recurrent Atrial Tachyarrhythmias After Ablation for Atrial Fibrillation.

Malasana G, Day JD, Weiss JP, Crandall BG, ... Nelson J, Bunch TJ
A Strategy of Rapid Cardioversion . Background: The significance of early recurrent atrial tachyarrhythmias after atrial fibrillation (AF) ablation is unclear. Atrial remodeling driven by these tachyarrhythmias can result in electrical, contractile, and structural changes that may impair long-term therapy success. Aggressive attempts to restore sinus rhythm in the temporal period of healing after ablation might improve outcomes. Methods: A total of 1,759 AF ablations were performed at Intermountain Medical Center or LDS Hospital. A total of 455 of those were among patients requiring repeat ablations. Patients were instructed to take their pulse daily and, if greater than 100 bpm or irregular, present the following business day fasting to the clinic for evaluation and cardioversion if AF or atrial flutter (AFL) were present. Results: Of the ablations performed, a total of 515 (29%, age: 65.6 ± 11.2 years, male: 57.9%) developed AF/AFL that required cardioverison. The majority of these arrhythmias first occurred in the initial 90 days (63.7%) postablation. During this period, 62.8% were on an antiarrhythmic drug (AAD). Only 25.1% were using an AAD at 3 months. The majority of ablations (75.6%) who experienced AF/AFL within the first 90 days after ablation were in sinus rhythm with no AAD at 1 year. Further, 48% of those with the first recurrence from 90 to 180 days were in sinus rhythm with no AAD at 1 year. Conclusions: The time at which the first recurrence of AF/AFL occurs impacts long-term outcomes. An aggressive strategy of rapid cardioversion postablation reduces the significance of recurrent AF/AFL during the first 6 months. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 09 Mar 2011; epub ahead of print
Malasana G, Day JD, Weiss JP, Crandall BG, ... Nelson J, Bunch TJ
J Cardiovasc Electrophysiol: 09 Mar 2011; epub ahead of print | PMID: 21385263
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Fix What is Broken: Scar Homogenization in Persistent Atrial Fibrillation.

Kaszala K, Ellenbogen KA
Our journey to solve the treatment problem of symptomatic persistent atrial fibrillation has been a difficult one. Results with antiarrhythmic drugs alone have been disappointing (1, 2). The Cox-Maze surgical approach has achieved excellent long-term outcomes(3), but applicability for stand-alone cases is limited due to the associated peri-operative morbidity. The failure to settle on a single best percutaneous approach is reflected by the divergent theoretical approaches that are used to treat persistent atrial fibrillation. The range of procedures that has been added or combined with pulmonary vein isolation alone for the treatment of persistent atrial fibrillation include ablation of complex fractionated electrograms (CFAE), creation of ablation lines in the left atrial roof, lateral or anterior mitral isthmus, right atrium, focal impulse and rotor modulation (FIRM), non-PV trigger ablation, and autonomic ganglionated plexus ablation as stand-alone procedures. Catheter ablation approaches in different centers utilizing widely different strategies have resulted in suboptimal or poorly reproducible outcomes with widely ranging published success rates between 11%-95%(4-8). It has been nearly impossible to reproduce Cox\'s surgical results with any number of different catheter ablation strategies despite multiple procedures. Even more confusion has been caused by the publication of the STAR AF II study(9) over a year ago and lead to a lack of enthusiasm for these complex strategies. A careful review of the STAR AF II trial shows that over 12 months there is a 40-50% failure rate with catheter ablation regardless of the approach. Failure of these approaches and the conception of persistent AF as a substrate problem where left atrial fibrosis may play a bigger role has led to exploration of newer avenues. Recent approaches to identify and isolate areas of left atrial scar has been reported to result in improved outcomes (10). This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 20 Jun 2016; epub ahead of print
Kaszala K, Ellenbogen KA
J Cardiovasc Electrophysiol: 20 Jun 2016; epub ahead of print | PMID: 27325346
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Initial Results of Efficacy of Left Linear Ablation Using a Novel Simultaneous Multielectrode Ablation Catheter.

Miyazaki S, Hocini M, Linton N, Jadidi AS, ... Jaïs P, Haïssaguerre M
LA Linear Ablation With Multielectrode Catheter. Introduction: Creating complete linear block with point-by-point ablation is challenging in the left atrium (LA). The purpose of this study was to evaluate the efficacy of LA linear ablation using a hexapolar linear multielectrode mapping/ablation catheter. Methods and results: Seventeen patients (age 57 ± 10, 14 male, 6 paroxysmal AF (PAF)) were studied and underwent linear ablation at the mitral isthmus (MI) and LA roof. Ablation was performed with 90 second, 60 °C applications of duty-cycled bipolar/unipolar radiofrequency in a 1:1 ratio simultaneously at all selected electrode pairs. The result could not be evaluated in 2 patients because AF persisted despite cardioversion. Roof line block was confirmed in 9 of 15 (60%) patients. The mean number of applications and the procedural time with and without block was 5.4 ± 2.4 and 4.5 ± 2.2 applications, and 15 ± 8 and 13 ± 7 minutes. MI block was confirmed in 4 of 15 (27%) patients. The mean number of RF applications with and without block was 5.3 ± 2.2 and 9.9 ± 4.4 applications, and the procedural time was 20 ± 9 and 27 ± 10 minutes, respectively. For patients with underlying persistent AF, power was lower than those with PAF but improved when ablation was performed in sinus rhythm. Char was observed in 2 cases; however, no procedure-related complications were observed. Conclusions: In our initial experience, a linear multielectrode catheter using duty-cycled bipolar and unipolar RF energy was inferior to conventional single point irrigated ablation in achieving LA linear block. However, successful linear block was obtained within a short period of time, when it was achieved. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).

J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print
Miyazaki S, Hocini M, Linton N, Jadidi AS, ... Jaïs P, Haïssaguerre M
J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print | PMID: 21235678
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Brugada Syndrome Diagnosed from the ECG Leads in the High Intercostal Spaces: Searching for Answers from a Higher Source?

Kumar S, Kalman JM
As is well known, Brugada syndrome is an autosomal dominant inherited disorder with variable expressivity that is characterized by ST-segment elevation in the right precordial leads and an increased risk of ventricular fibrillation and sudden cardiac death.(1) Since the seminal report of this condition by Brugada and Brugada in 1992,(2) no other inherited arrhythmogenic disorder has perhaps generated more passionate debate than BrS, with many controversies related to the underlying mechanism, methods of risk stratification, prognosis of its phenotypic manifestations and its long term management.(1-) Of paramount importance are two competing theories of the underlying mechanism of arrhythmogenesis. The depolarization hypothesis proposes that defective sodium channel function (leading to a weak inward sodium current during phase 1 of the action potential), in combination with a unopposed transient outward current (Ito ), which is most prominent in the right ventricular outflow tract (RVOT) epicardium leads to an accentuation of the action potential notch in the RV epicardium rather than the endocardium, resulting in an accentuated J wave and ST segment elevation characteristic of the Brugada pattern EKG.(1) This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 24 May 2016; epub ahead of print
Kumar S, Kalman JM
J Cardiovasc Electrophysiol: 24 May 2016; epub ahead of print | PMID: 27221147
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How Carbon Beams May Make Extracorporeal Ablation for Atrial Fibrillation a Reality.

Bunch TJ, Cutler MJ
To truly understand the potential value of using a carbon ion beam to treat atrial fibrillation requires a brief historical review of the treatment of symptomatic bradycardia with pacemakers. In 1580 Geronimo Mercuriale found and reported that a slow pulse rate was associated with syncope.(1) Over two hundred years later, Luigi Galvani in 1791 reported that electricity was innate in organic tissue in a series of studies involving stimulation of frog leg muscles with electrically charged brass hooks placed in the spinal cord.(2) He also reported cardiac contractions with similar electrical stimulation in a frog heart. Approximately 10 years later Alessandro Volta created the first battery that could create electricity independent of electrostatic machines. In 1856, Rudolph Albert von Kollicker showed that each frog heart beat was the result of electrical stimulus.(3) In 1887 Augustus Desire\' Waller reported that each heartbeat begins at one point of the organ and propagates to the other end.(2) This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 03 Jan 2016; epub ahead of print
Bunch TJ, Cutler MJ
J Cardiovasc Electrophysiol: 03 Jan 2016; epub ahead of print | PMID: 26725564
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Ventricular Resynchronization by Implementation of Direct His Bundle Pacing in a Patient with Congenital Complete AV Block and Newly Diagnosed Cardiomyopathy.

Rehwinkel AE, Müeller J, Vanburen PC, Lustgarten DL
Direct His Bundle Pacing in Congenital AV Block. Congenital complete atrioventricular block (CCAVB) is usually due to failure of AV nodal conduction with preservation of the His Purkinje system, typically present at birth. While most patients with CCAVB ultimately require pacemaker therapy to restore physiologic heart rates, recent studies have suggested that chronic right ventricular (RV) pacing in patients with CCAVB can have detrimental effects on cardiac structure and function, and may account for a 7-10% incidence of congestive heart failure in these patients. Since the His Purkinje system is preserved in CCAVB, this patient population could be uniquely well served by direct His bundle pacing (DHBP) which would be expected to restore physiologic activation of both ventricles. We present a case of a young woman who presented with RV pacing-induced cardiomyopathy who responded dramatically to DHBP. (J Cardiovasc Electrophysiol, Vol. pp. 1-4).

J Cardiovasc Electrophysiol: 07 Dec 2010; epub ahead of print
Rehwinkel AE, Müeller J, Vanburen PC, Lustgarten DL
J Cardiovasc Electrophysiol: 07 Dec 2010; epub ahead of print | PMID: 21134028
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Substrate Mapping and Ablation for Ventricular Tachycardia: The LAVA approach.

Sacher F, Lim HS, Derval N, Denis A, ... Haissaguerre M, Jaïs P
Catheter ablation of ventricular tachycardia (VT) is proven effective therapy particularly in patients with frequent defibrillator shocks. However, the optimal endpoint for VT ablation has been debated and additional endpoints have been proposed. At the same time, ablation strategies aiming at homogenizing the substrate of scar related VT have been reported. Our method to homogenize the substrate consists of local abnormal ventricular activity (LAVA) elimination. LAVA are high frequency sharp signals that represent near-field signals of slowly conducting tissue and hence potential VT isthmuses. Pacing maneuvers are sometimes required to differentiate them from far-field signals. Delayed enhancement on cardiac MRI and/or wall thinning on Multi-Detector Computed Tomography are also extremely helpful to identify the areas of interest during ablation A strategy aiming at careful LAVA mapping, ablation and elimination is feasible and can be achieved in about 70% of patients with scar related VT. Complete LAVA elimination is associated with a better outcome when compared to LAVA persistence even when VT is rendered non-inducible. This is a simple approach, with a clear endpoint and the ability to ablate in sinus rhythm. This strategy significantly benefits from high definition imaging, mapping, and epicardial access. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Oct 2014; epub ahead of print
Sacher F, Lim HS, Derval N, Denis A, ... Haissaguerre M, Jaïs P
J Cardiovasc Electrophysiol: 19 Oct 2014; epub ahead of print | PMID: 25328104
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Mapping and Ablating Ventricular Premature Contractions that Trigger Ventricular Fibrillation: Trigger Elimination and Substrate Modification.

Nogami A
Mapping and Ablating the Trigger of Ventricular Fibrillation. Ventricular fibrillation (VF) is a malignant arrhythmia, usually initiated by a ventricular premature contraction (VPC) during the vulnerable period of cardiac repolarization. Ablation therapy for VF has been described and increasingly reported. Targets for VF triggers are VPC preceded Purkinje potentials or the right ventricular outflow tract (RVOT) in structurally normal hearts, and VPC triggers preceded by Purkinje potentials in ischemic cardiomyopathy. The most important issue before the ablation session is the recording of the 12-lead ECG of the triggering event, which can prove invaluable in regionalizing the origin of the triggering VPC for more detailed mapping. In cases where the VPC is not spontaneous or inducible, ablation may be performed by pacemapping. During the session, mapping should be focused on the earliest activation and determining the earliest potential is the key to a successful ablation. However, a modification of the Purkinje network might be applied when the earliest site cannot be determined or is located close to the His-bundle. Furthermore, the electrical isolation of the pulmonary artery (PA) can suppress RVOT type polymorphic ventricular tachycardia in some patients with rapid triggers from the PA. Suppression of VF can be achieved by not only the elimination of triggering VPCs, but also by substrate modification of possible reentry circuits in the Purkinje network, or between the PA and RVOT. Further studies are needed to evaluate the precise mechanisms of this arrhythmia. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 11 Sep 2014; epub ahead of print
Nogami A
J Cardiovasc Electrophysiol: 11 Sep 2014; epub ahead of print | PMID: 25216244
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High Washout Rate of Iodine-123-Metaiodobenzylguanidine Imaging Predicts the Outcome of Catheter Ablation of Atrial Fibrillation.

Arimoto T, Tada H, Igarashi M, Sekiguchi Y, ... Kuga K, Aonuma K
( 123 ) I-MIBG and Ablation for Atrial Fibrillation. Introduction: Excessive sympathetic nervous activity may contribute to atrial fibrillation (AF) recurrences after ablation, but its precise role remains controversial. The goals of this study were to assess the effects of AF on the iodine-123-metaiodobenzylguanidine ((123) I-MIBG) findings and to elucidate its impact on the procedural outcome in patients undergoing a first-time catheter ablation to treat AF. Methods and results: This study included 88 consecutive patients with paroxysmal (n = 48) or persistent (n = 40) AF who underwent radiofrequency catheter ablation and (123) I-MIBG scintigraphy. Five days after the ablation of AF, (123) I-MIBG scintigraphy was performed during sinus rhythm. Anterior planar imaging was obtained at 15 minutes and 180 minutes and the washout rate of the (123) I-MIBG was calculated. The (123) I-MIBG scintigraphy demonstrated an enhanced adrenergic nervous function (high washout rate) and decreased adrenergic nervous distribution (low heart to mediastinum ratios) in patients with both paroxysmal and persistent AF. During a mean follow-up period of 13.5 ± 2.2 months after the ablation, 25 (28%) patients had AF recurrences. The univariate predictors of an AF recurrence were the duration of the AF history, left atrial dimension, and washout rate of the (123) I-MIBG. Only the (123) I-MIBG washout rate was a multivariate predictor of an AF recurrence (hazard ratio: 1.6, 95% confidence interval: 1.004-1.125, P = 0.037). Conclusions: Excessive sympathetic nervous activation may be one of the mechanisms of AF recurrences. The evaluation of the cardiac nerve activity using (123) I-MIBG scintigraphy shortly after the AF ablation may be a promising tool to predict the patient\'s outcome. (J Cardiovasc Electrophysiol, Vol. pp. 1-8).

J Cardiovasc Electrophysiol: 22 Jun 2011; epub ahead of print
Arimoto T, Tada H, Igarashi M, Sekiguchi Y, ... Kuga K, Aonuma K
J Cardiovasc Electrophysiol: 22 Jun 2011; epub ahead of print | PMID: 21692898
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Narrow QRS Tachycardia in a Patient with Spongiform Cardiopathy and Preexcitation: What Is the Mechanism?

Matía R, Hernández-Madrid A, Sánchez I, Lumia G, ... Zamorano JL, Moreno J
A 19-year-old man diagnosed with spongiform cardiomyopathy and ventricular preexcitacion was referred to our hospital for electrophysiological (EP) testing after a syncopal episode. Baseline electrocardiogram (ECG) showed ventricular preexcitation consistent with the presence of a superior paraseptal, anteroseptal, accessory pathway (AP). After triple femoral vein puncture a decapolar catheter was placed in the coronary sinus, a tetrapolar catheter in the His bundle region (with no clear His deflection recorded thorough the EP study) and a 4mm-tip irrigated ablation catheter initially at the RV apex. Programmed atrial extrastimuli from the coronary sinus reproducibly induced nonsustained and sustained episodes of an irregular narrow QRS tachycardia with apparent atrioventricular dissociation in the surface ECG (figure 1). Intracardiac recording during ongoing tachycardia are also shown (figures 2 and 3). What is the involved mechanism? This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 08 Sep 2014; epub ahead of print
Matía R, Hernández-Madrid A, Sánchez I, Lumia G, ... Zamorano JL, Moreno J
J Cardiovasc Electrophysiol: 08 Sep 2014; epub ahead of print | PMID: 25199432
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Oral Anticoagulant Use Around the Time of Atrial Fibrillation Ablation: A Review of the Current Evidence of Individual Oral Anticoagulant Use for Periprocedural Atrial Fibrillation Ablation Thromboembolic Prophylaxis.

Garton AB, Dudzinski J, Kowey PR
Atrial fibrillation is the most common arrhythmia and ablation is becoming more prevalent as a treatment option. Appropriate treatment of atrial fibrillation mandates thromboembolic prophylaxis, and atrial fibrillation ablation periprocedural management of oral anticoagulation is paramount because of the unique susceptibility for thromboembolism that exists for a patient undergoing ablation. Uninterrupted warfarin therapy is the current standard approach for periprocedural atrial fibrillation anticoagulation. Novel oral anticoagulants, including direct thrombin and factor Xa inhibitors, are being used more frequently for thromboembolic prophylaxis in atrial fibrillation patients, but the best strategy for using novel oral anticoagulants in periprocedural anticoagulation is unknown. Optimal periprocedural anticoagulation management strategies with oral anticoagulants, limitations of using novel oral anticoagulants, and future directions in this field are discussed. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 11 Sep 2014; epub ahead of print
Garton AB, Dudzinski J, Kowey PR
J Cardiovasc Electrophysiol: 11 Sep 2014; epub ahead of print | PMID: 25216104
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How Can We Best Describe the Cardiac Components?

Anderson RH, Mori S
In the current issue of the Journal, Wang and colleagues, from Jilin in China, show the advantages now to be gained when cardiac anatomy is assessed using multi-detector computed tomography.(1) One of us stated recently,(2) when commentating on a publication published in the Journal by his current co-author and colleagaues,(3) that such clinical investigation was likely to become the gold standard for assessment of cardiac anatomy. The investigation of the inferior pyramidal space(3) showed that the features could be demonstrated with as much accuracy, if not more, than that provided by the prosector holding the heart in his or her hands in the dissecting room. The investigation now reported by the Chinese investigators(1) continues this trend, showing that such subtle features as the location of the phrenic nerves could be demonstrated in up to nine-tenth of patients, albeit that the course of the right phenic nerve was shown in only half the cohort. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 18 May 2016; epub ahead of print
Anderson RH, Mori S
J Cardiovasc Electrophysiol: 18 May 2016; epub ahead of print | PMID: 27196365
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Congestive Heart Failure After Extensive Catheter Ablation for Atrial Fibrillation: Prevalence, Characterization, and Outcome.

Tan HW, Wang XH, Shi HF, Sun YM, ... Yang GS, Liu X
Congestive Heart Failure After Catheter Ablation for AF. Introduction: This study sought to describe a new complication of catheter ablation for atrial fibrillation (AF): new onset congestive heart failure (CHF) after extensive ablation for AF. Methods and results: Data from 12 patients developing CHF after ablation were prospectively collected. All patients underwent extensive ablation for AF including circumferential pulmonary venous ablation and complex fractionated atrial electrograms guided ablation. CHF was diagnosed using the following criteria: symptoms or signs of heart failure, elevated BNP, and echocardiographic evidence of left ventricular diastolic dysfunction. Twelve patients (5 persistent and 7 permanent AF) had CHF after extensive ablation out of 484 consecutive AF patients who underwent catheter ablation (prevalence 2.5%). None of these 12 patients had CHF prior to the procedure. The mean onset of the symptoms was 39 ± 14 hours after the index procedure. Dyspnea and pulmonary rales were the most observed symptoms or signs. White blood cell count, serum CRP, BNP, and echocardiographic parameters of left ventricular diastolic dysfunction (E/A, E/E\') were significantly increased after the onset of symptoms. All patients had complete recovery with supportive therapy within 3 days of the onset of symptoms. Conclusions: In this single-center experience, CHF after extensive ablation for AF was a well-recognized complication with a relatively high incidence of 2.5%. Measurement of BNP, CRP, and E/A, E/E\' is useful in managing these patients. (J Cardiovasc Electrophysiol, Vol. pp. 1-6).

J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print
Tan HW, Wang XH, Shi HF, Sun YM, ... Yang GS, Liu X
J Cardiovasc Electrophysiol: 17 Jan 2011; epub ahead of print | PMID: 21235663
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Randomized Comparison of Cavotricuspid Isthmus Ablation for Atrial Flutter Using an Open Irrigation-Tip versus a Large-Tip Radiofrequency Ablation Catheter.

Ilg KJ, Kühne M, Crawford T, Chugh A, ... Morady F, Oral H
Ablation of Typical Atrial Flutte. Background: Large-tip (10 mm) catheters (LTCs) and open-irrigation-tip catheters (OITCs), both capable of creating large lesions, are more effective than conventional catheters for cavotricuspid isthmus (CTI) ablation. However, it is not clear whether complete CTI block can be achieved more efficiently using an LTC or an OITC. The purpose of this study was to compare the efficiency of radiofrequency catheter ablation (RFA) of the CTI using LTC versus OITC to eliminate atrial flutter (AFL). Methods and results: Sixty consecutive patients (age = 62 ± 10 years) with typical AFL were randomized to undergo RFA of CTI using an LTC (10 mm) or an OITC. If complete CTI block was not achieved by ≤30 minutes of RFA, patients were allowed to cross over to ablation with the other catheter. A 3-dimensional electroanatomical mapping system was used for catheter navigation only with the OITC. The mean duration of RFA to achieve CTI block in 50% of the patients was 6.8 ± 2.2 minutes with an LTC and 11.7 ± 2.7 minutes with an OITC (P = 0.001). After 30 minutes of RFA, CTI block was achieved in 26/30 (87%) and 25/30 patients (83%) using an LTC and an OITC, respectively (P = 1.0). After crossover, CTI block was achieved in 4/5 (80%) and in 4/4 patients (100%) with an LTC and OITC, respectively (P = 1.0). LTC was associated with a lower volume of intravenous fluid administration (388 ± 365 mL versus 865 ± 451 mL, P = 0.0001) and a trend for shorter procedure duration (95 ± 31 minutes versus 114 ± 50 minutes, P = 0.09) than the OITC. At 6 ± 3 months, 30/30 patients (100%) in the LTC and 27/30 patients (90%) in the OITC groups remained free from AFL, respectively (P = 0.24). Except for one inconsequential steam-pop during RFA with the OITC, there were no complications. Conclusions: Complete CTI block is achieved more rapidly using an LTC than an OITC, and with a similar clinical efficacy. (J Cardiovasc Electrophysiol, Vol, pp. 1-6).

J Cardiovasc Electrophysiol: 01 Apr 2011; epub ahead of print
Ilg KJ, Kühne M, Crawford T, Chugh A, ... Morady F, Oral H
J Cardiovasc Electrophysiol: 01 Apr 2011; epub ahead of print | PMID: 21453368
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Catheter Ablation of Ventricular Arrhythmias Arising from the Right Ventricular Septum Close to the His Bundle: Features of the Local Electrogram at the Optimal Ablation Site.

Komatsu Y, Otomo K, Taniguchi H, Kakita K, ... Fujiwara H, Iesaka Y
Ablation of Para-Hisian Ventricular Arrhythmias. Introduction: The characteristics of the local electrogram at the optimal ablation site of ventricular arrhythmias (VAs) originating from the right ventricle close to the His bundle (HB) region have rarely been described. Methods and results: Among 190 consecutive patients with idiopathic VAs with left bundle branch block morphology and inferior-axis deviation, 16 were found to have successful ablation site in the right ventricle close to the HB region (para-Hisian group). The electrophysiologic data were compared between the patients in the para-Hisian group and those with VAs arising from the right ventricular (RV) outflow tract (RVOT group). The distal bipolar electrogram at the successful ablation sites in the para-Hisian group exhibited a significantly greater R-wave duration, lower R-wave amplitude, and slower upright deflection of the initial R wave than did those in the RVOT group (all P < 0.001). In the para-Hisian group, a total of 56 radiofrequency (RF) energy applications were delivered, of which the local electrograms at 16 successful and 40 unsuccessful ablation sites were reviewed. High-frequency R-wave potentials of the bipolar electrogram were present in 14 (88%) of the successful ablation sites. An R-wave duration of greater than 34 ms had a discriminatory power for indicating the site of a successful ablation (area under the receiver-operator characteristics curve 0.90, sensitivity 94%, specificity 80%). Conclusions: The successful ablation site of the para-Hisian VAs had distinctive local electrogram characteristics. A longer R-wave duration of the bipolar electrogram with high-frequency potentials could be a novel predictor of a successful ablation. (J Cardiovasc Electrophysiol, Vol. pp. 1-8).

J Cardiovasc Electrophysiol: 21 Feb 2011; epub ahead of print
Komatsu Y, Otomo K, Taniguchi H, Kakita K, ... Fujiwara H, Iesaka Y
J Cardiovasc Electrophysiol: 21 Feb 2011; epub ahead of print | PMID: 21332864
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Approach to the Catheter Ablation Technique of Paroxysmal and Persistent Atrial Fibrillation: A Meta-Analysis of the Randomized Controlled Trials.

Parkash R, Tang AS, Sapp JL, Wells G
Review of the Catheter Ablation Technique in AF. Background: Several randomized controlled trials (RCTs) have been published to investigate the optimal techniques for atrial fibrillation (AF) ablation. Many of these are small in number and include both paroxysmal and persistent AF; however, the techniques for each of these types of AF may differ. Method and Results: We searched MEDLINE, EMBASE, and the Cochrane Controlled Trials Register for RCTs evaluating AF ablation for either paroxysmal or persistent AF. The primary endpoint was freedom from AF after a single procedure. A total of 35 unique randomized controlled trials were found to fulfill the criteria. A significant degree of heterogeneity was present given the differing sample sizes, populations studied, and outcomes. Radiofrequency ablation (RFA) was found to be favorable in prevention of AF over antiarrhythmic drugs (AADs) in either paroxysmal (5 studies, RR 2.26; 95% CI 1.74, 2.94) or persistent AF (5 studies, RR 3.20; 95% CI 1.29, 8.41). When comparing specific techniques, wide-area PVI appeared to offer the most benefit for both paroxysmal (6 studies, RR 0.78; 95% CI 0.63, 0.97) and persistent AF (3 studies, RR 0.64; 95% CI 0.43, 0.94). CFE ablation provided only benefit for persistent AF when combined with antral PVI (4 studies, RR 0.55; 95% CI 0.34, 0.87). Conclusions: Despite significant methodological limitations, it appears that additional ablations beyond PVI are necessary for persistent AF but not proven for paroxysmal AF. The optimal technique for persistent AF, however, deserves a further study, in the setting of a large, randomized controlled trial. >(J Cardiovasc Electrophysiol, Vol. pp. 1-10).

J Cardiovasc Electrophysiol: 21 Feb 2011; epub ahead of print
Parkash R, Tang AS, Sapp JL, Wells G
J Cardiovasc Electrophysiol: 21 Feb 2011; epub ahead of print | PMID: 21332861
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Localized Reentry within a Previous Mitral Isthmus Line Ablation.

Hooks DA, Sacher F, Haissaguerre M, Derval N
A 60-year-old woman presented for radiofrequency ablation of persistent atrial tachycardia (AT) one year after pulmonary vein isolation and mitral isthmus linear ablation for atrial fibrillation. The AT (CL 288ms) was mapped using the Orion(TM) multipolar basket catheter and Rhythmia(TM) mapping system (Boston Scientific, MA, USA). Mapping points (n = 12,385) were obtained from the basket catheter (64 electrodes of 0.4mm(2) area; 2.5mm spacing) using continuous (automated) acquisition over 16 minutes, with standard beat acceptance criteria: (i) variation of CL < 13 ms, (ii) variation of activation time difference between coronary sinus (CS) electrograms < 5ms, (iii) respiration phase gated to within 13.6 μV, (iv) catheter motion < 1.7 mm per beat, and (v) catheter tracking uncertainty < 3 mm. The activation map (figure panel A) revealed localized counter-clockwise reentry within the previous mitral isthmus ablation line, appreciated in more detail in the accompanying cine frames (panel A) and Online Movie. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 21 Sep 2015; epub ahead of print
Hooks DA, Sacher F, Haissaguerre M, Derval N
J Cardiovasc Electrophysiol: 21 Sep 2015; epub ahead of print | PMID: 26391632
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Early Procedure-related Adverse Events by Gender in MADIT-CRT.

Jamerson D, McNitt S, Polonsky S, Zareba W, Moss A, Tompkins C
Whether gender differences exist in procedure-related adverse events following CRT-D implantation is unknown. We investigated the type and frequency of procedure-related adverse events among those enrolled in MADIT-CRT and identified clinical predictors for gender-specific events. We compared differences in the rate of procedure-related adverse events by gender (444 females and 1,346 males) that occurred ≤ 30 days after the index procedure in the ICD and CRT-D groups. Eight types of major adverse events were identified, defined as procedure-related complications deemed potentially life-threatening. Best subset regression analysis (p<0.10) was performed to identify baseline clinical factors associated with procedure-related adverse events that differed by gender. Women randomized to CRT-D received a greater reduction in the risk of heart failure or death versus men (p<0.001). Women were twice as likely as men to experience a major procedure-related adverse event (6.3% vs. 2.7%; p<0.001), including pneumothorax/ hemothorax (3% vs. 1%; p<0.001). Women were more likely to experience a major adverse event related to CRT-D than ICD implantation (7.7% vs. 2.9%; p = 0.018). Clinical predictors of major adverse events in females were smaller body mass index (BMI), elevated blood urea nitrogen, and elevated creatinine. The main predictor for pneumothorax/ hemothorax was reduced BMI for women and men. Women demonstrate greater clinical benefit from CRT than men but are more likely to experience adverse procedure-related events within the first 30 days after device implantation. A smaller BMI seems to be a major factor associated with pneumothorax/hemothorax in both females and males. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 23 Apr 2014; epub ahead of print
Jamerson D, McNitt S, Polonsky S, Zareba W, Moss A, Tompkins C
J Cardiovasc Electrophysiol: 23 Apr 2014; epub ahead of print | PMID: 24758374
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Repeated Radiofrequency Ablation of Atrial Tachycardia in Restrictive Cardiomyopathy Secondary to Myofibrillar Myopathy.

Stöllberger C, Gatterer E, Finsterer J, Kuck KH, Tilz RR
Myofibrillar myopathy is characterized by non-hyaline and hyaline lesions due to mutations in nuclear genes encoding for extra-myofibrillar or myofibrillar proteins. Cardiac involvement in myofibrillar myopathy may be phenotypically expressed as dilated, hypertrophic or restrictive cardiomyopathy. Radiofrequency ablation of atrial fibrillation and flutter has so far not been reported in myofibrillar myopathy. We report the case of a young female with myofibrillar myopathy and deteriorating heart failure due to restrictive cardiomyopathy and recurrent atrial fibrillation and atrial tachycardias intolerant to pharmacotherapy. Cardiac arrhythmias were successfully treated with repeat radiofrequency ablations and resulted in regression of heart failure, thus postponing the necessity for cardiac transplantation. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 23 Apr 2014; epub ahead of print
Stöllberger C, Gatterer E, Finsterer J, Kuck KH, Tilz RR
J Cardiovasc Electrophysiol: 23 Apr 2014; epub ahead of print | PMID: 24758315
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Antitachycardia Pacing Therapy for the Successful Treatment of Lead Fracture.

Bhimani AA, Deeprasertkul P, Nannapaneni N, Carayannopoulos GN
A 35-year-old man with non-ischemic cardiomyopathy underwent a single chamber implantable cardioverter defibrillator (ICD) implant with a St. Jude Medical Fortify VR pulse generator and an active fixation ventricular lead (St. Jude Durata model 7121, 65 cm) for the primary prevention of sudden cardiac arrest. Twenty months after device implant, he presented to our clinic for evaluation of a "funny sensation" in his chest. Device evaluation revealed ventricular sensing amplitude 2.4 mV, lead impedance 1500 ohms, and pacing capture threshold was 2.0 V @ 0.5 msec, which were all stable over the prior 6 months. The tachycardia detections were set for two zones: ventricular tachycardia (VT), 181-221 beats per minute (bpm), and ventricular fibrillation (VF), greater than 221 bpm. Antitachycardia pacing (ATP) therapies were programmed in both zones. In addition to several nonsustained VF events, there were two episodes of tachycardia in the VF zone, occurring on different days, for which ATP was delivered and noted to be successful (Figure 1). The figure shows electrical noise on the bipolar signal that was not seen on the far-field signal and did not correlate with any causes of external noise according to the patient. Interestingly, the noise disappeared instantly after ATP on both occasions. Though this phenomenon has been reported after some ICD shocks, the reasons have not been clarified. Polarization of the conductor allowing normal signal transmission is a possibility or a new position of the lead or patient as a result of the ICD therapy may explain the loss of lead noise. As a result, Figure 1 shows what appears to be effective therapy for lead fracture noise using ATP. Nonetheless, due to the diagnosis of lead fracture (without conductor externalization), he underwent successful right ventricular lead replacement. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 29 Oct 2014; epub ahead of print
Bhimani AA, Deeprasertkul P, Nannapaneni N, Carayannopoulos GN
J Cardiovasc Electrophysiol: 29 Oct 2014; epub ahead of print | PMID: 25354719
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Abstract

Primary versus secondary atrial fibrillation: Is it time for a different classification of atrial fibrillation?

Laish-Farkash A, Suleiman M
The phenotypic classification of atrial fibrillation (AF) into paroxysmal, persistent, longstanding persistent, and permanent AF (1) is clinically useful and is employed to communicate its persistence, to select appropriate therapies, and to define inclusion criteria in clinical studies. However, this classification poorly reflects objective AF temporal persistence,(2) is influenced by clinical patient characteristics,(2) and does not reflect the underlying pathophysiology and substrate characteristics of the atria. The landmark concept underlying the phenotypic classification is that "AF begets AF",(3) where AF is the only driver of the disease in a self-perpetuating process of "first and second factors" that form a substrate capable of maintaining AF over time.(4,5) This paradigm might not be the underlying mechanism in all AF cases. There are AF patients in whom AF is secondary to structural heart disease and there are AF patients in whom AF is a manifestation of a primary fibrotic disease of the atria. This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 21 Sep 2015; epub ahead of print
Laish-Farkash A, Suleiman M
J Cardiovasc Electrophysiol: 21 Sep 2015; epub ahead of print | PMID: 26391544
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This program is still in alpha version.