An unprecedented cause of cardiac resynchronization with defibrillator (CRT-D) malfunction \"A beheaded generator assembly\".

Prasitlumkum N, Ding K, Doyle K, Pai RG, Lo R
Cardiac resynchronization with defibrillator (CRT-D) malfunction can be due to various reasons, including wire injury, insulation break, battery problems, or patient factors. Undesired outcomes can be dramatically elevated in those settings, prompting early detection and proper troubleshooting. To diagnose, clinical correlation and device interrogation are vital. However, it is not uncommon to find general troubleshooting options insufficient, as highlighted in this case report. Here, we presented an unusual \"head assembly separation,\" as the main reason for abnormal device parameters.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 31 Mar 2022; 33:769-772

Outcomes of leadless pacemaker implantation in patients with mechanical heart valves.

Loughlin G, Pachón M, Martínez-Sande JL, Ibáñez JL, ... Cuesta J, Arias MA
Introduction
Device infections constitute a major complication of transvenous pacemakers. Mechanical heart valves (MHV) increase the risk of infective endocarditis (IE) and pacemaker infection, requiring lifelong vitamin K-antagonists (VKA), which may affect patient management. Leadless pacemakers (LP) are associated with low infection rates, posing an attractive option in MHV patients requiring permanent pacing. This study describes outcomes following LP implantation in patients with MHV.
Methods
This is a multicenter, observational, retrospective study including consecutive patients implanted with an LP at 5 centers between June 2015 and January 2020. Procedural outcomes, antithrombotic management, complications, performance during follow-up and episodes of bacteremia and IE were compared between patients with and without an MHV (MHV and non-MHV groups).
Results
Four hundred fifty-nine patients were included (74 in the MHV group, 16.1%, and 385 in the non-MHV group, 83.9%). Procedural outcomes and acute electrical performance were comparable between groups. Vascular complications and cardiac perforation occurred in 2.7 versus 2.3% (p = 1) and 0% versus 0.8% (p = 1) in the MHV group and non-MHV group. One case of IE occurred in the MHV group and 2 in the non-MHV group. In MHV patients, uninterrupted VKA was used in 83.8%, whereas 16.2% were heparin-bridged. Vascular complication or tamponade occurred in 1 (8.3%) MHV heparin-bridged patient versus 1 (1.6%) MHV uninterrupted VKA patient (p = .3).
Conclusion
LP implantation outcomes in MHV patients are comparable to the general LP population. Device-related infections are rare following LP implantation, including in patients with MHV. In the MHV group, periprocedural anticoagulation management was not associated with significantly different rates of tamponade or vascular complication.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Apr 2022; 33:997-1004

Vein of Marshall alcohol ablation for dormant pulmonary vein conduction: A case report.

Janga C, Madhavan M, Siontis KC, Killu AM
We report a case of alcohol ablation into a vein of Marshall for recurrent dormant conduction into the pulmonary veins with adenosine testing in a patient where two prior ablation attempts failed to isolate the left vein.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Apr 2022; 33:1070-1071

Reply to \"Pro-arrhythmia with Anti-arrhythmic Drugs in Patients with Idiopathic Ventricular Arrhythmia: A Common Problem with Vague Definitions and Complex Interactions\".

Tang JKK, Deyell MW
Drs. Hasdemir and Payzin have cogently brought up one of the primary challenges in studying patients with frequent premature ventricular complexes (PVCs) and evaluating the impact of therapy. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 20 Apr 2022; epub ahead of print

Response to Letter to the Editor regarding \'Characteristics and outcomes of ventricular tachycardia and premature ventricular contractions ablation in patients with prior mitral valve surgery\'.

Khalil F, Killu AM
We would like to thank the authors for their letter and interest in our manuscript. We appreciate their valuable comments. The authors have raised the following important points: 1. The heterogenicity of our cohort with mitral valve surgery (MVS) 2. Elucidating the characteristics and causes of ventricular arrhythmias (VA) in patients with primary versus secondary mitral disease as well as in those with ischemic versus non-ischemic heart disease 3. The paucity of cardiac magnetic resonance imaging (MRI) as a limitation of the study 4. The need for careful evaluation of patients prior to ablation since most arrhythmias did not originate from the perimitral area. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Apr 2022; epub ahead of print

Calculated Parameters of Luminal Esophageal Temperatures predict Esophageal Injury following Conventional and High-Power Short-Duration Radiofrequency Pulmonary Vein Isolation.

Meininghaus DG, Freund R, Kleemann T, Christoph Geller J
Background
Luminal esophageal temperature (LET) monitoring is not associated with reduced esophageal injury following pulmonary vein isolation (PVI).
Objective
Detailed analysis of (the temporal and spatial gradients of) LET measurements may better predict the risk for esophageal injury.
Methods
Between January 2020 and December 2021, LET maxima, duration of LET rise above baseline, and area under the LET curve (AUC) were calculated offline and correlated with (endoscopy and endoscopic ultrasound detected) esophageal injury (i.e., mucosal esophageal lesions [ELs], periesophageal edema, and gastric motility disorders) following PVI using moderate-power moderate-duration (MPMD [25-30 W/25-30s]) and high-power short-duration (HPSD [50 W/13s]) radiofrequency (RF) settings.
Results
63 patients (69±9 years old, 32 male, 51 MPMD and 12 HPSD) were studied. Esophageal injury was frequent (40% in both groups), mucosal ELs were more common with MPMD, edema was frequently observed following HPSD. RF-duration, total RF-energy at the left atrial (LA) posterior wall, and distance between LA and esophagus were not different between patients with/without esophageal injury. In contrast to LET and LET duration above baseline, AUC was the best predictor and significantly increased in patients with esophageal injury (3,422 vs. 2,444 K^. s).
Conclusion
For both ablation strategies, AUC of the LET curves best predicted esophageal injury. HPSD is associated with similar rates of esophageal injury when (mostly subclinical) periesophageal alterations (that are of unclear clinical relevance) are included. Whether integration of these calculated LET parameters is useful to prevent esophageal injury remains to be seen. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 20 Apr 2022; epub ahead of print

Grid-mapping catheters versus PentaRay catheters for left atrial mapping on Ensite Precision mapping system.

Saito J, Yamashita K, Numajiri T, Gibo Y, ... Isomura N, Ochiai M
Introduction
Areas displaying reduced bipolar voltage are defined as low-voltage areas (LVAs). Moreover, left atrial (LA) LVAs after pulmonary vein isolation (PVI) have been reported as a predictor of recurrent atrial fibrillation (AF). In this study, we compared grid mapping catheter (GMC) with PentaRay catheter (PC) for LA voltage mapping on Ensite Precision mapping system.
Methods
Twenty-six consecutive patients with LVAs and border zone within the LA were enrolled. After achieving PVI, voltage mapping under high right atrial pacing for 600msec was performed twice using each catheter type (GMC first, PC next). Furthermore, LVA was defined as a region with a bipolar voltage of <0.50, and border zone was defined as a region with a bipolar voltage of <1.0, or <1.5 mV.
Results
Compared with PC, using GMC, voltage mapping contained more mapping points (20242［15859, 26013］ vs 5589［4088,7649］; P < .0001), and more mapping points per minute(1428［1275, 1803］ vs 558［372,783］; P < .0001). In addition, LVA and border zone size using GMC was significantly less than that reported using PC: <1.0 mV (5.9 cm² ［2.9, 20.2］ vs. 13.9 cm² ［6.3, 24.1］, P = 0.018) and <1.5mV voltage cutoff (10.6 cm² ［6.6, 27.2］ vs. 21.6 cm² ［12.6, 35.0］, P = 0.005).
Conclusion
Bipolar voltage amplitude estimated by GMC was significantly larger than that estimated by PC on Ensite Precision mapping system. GMC may be able to find highly selective identification of LVAs with lower prevalence and smaller LVA and border zone size. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Apr 2022; epub ahead of print

Insurance Lesions: Does a Second Lesion Make a Difference?

Toloczko A, Buchan S, John M, Post A, Razavi M
Introduction
In radiofrequency ablation procedures for cardiac arrhythmia, the efficacy of creating repeated lesions at the same location (\"insurance lesions\") remains poorly studied. We assessed the effect of type of tissue, power, and time on the resulting lesion geometry during such multiple ablation procedures.
Methods and results
A custom ex vivo ablation model was used to assess lesion formation. An ablation catheter was oriented perpendicular to the tissue and used to create lesions that varied by type of tissue (atrial or ventricular free wall), power (30 or 50 W), and time (30, 40, or 50 s for standard ablations and 5, 10, or 15 s for high-power, short-duration [HPSD] ablations). Lesion dimensions were recorded and then analyzed. Radiofrequency ablations were performed on 57 atrial tissue samples (28 HPSD, 29 standard) and 28 ventricular tissue samples (all standard). With ablation parameters held constant, performing multiple ablations significantly increased lesion depth in ventricular tissue when ablations were performed at 30 W for 50 seconds. No other set of ablation parameters was shown to affect the width or depth of the resulting lesions in either tissue type.
Conclusion
Multiple ablations created with the same power and time, delivered within 30 seconds of each other at the same exact location, offer no meaningful benefit in lesion depth or width over single ablations, with the exception of ventricular ablation at 30 W for 50 s. Given the risks associated with excessive ablation, our results suggest that this practice should be re-evaluated by clinical electrophysiologists. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Apr 2022; epub ahead of print

The Hybrid Convergent Procedure for Persistent and Long-Standing Persistent Atrial Fibrillation From an Electrophysiologist\'s Perspective.

DeLurgio DB
In atrial fibrillation (AF), the pulmonary veins (PV) are central to arrhythmogenicity and are targeted by PV isolation (PVI). As AF progresses, triggers become more prevalent in non-PV areas including the left atrial posterior wall (LAPW). Reported benefits of LAPW isolation in Cox-maze IV led to exploration of ablation strategies using endocardial catheters. However, no single approach to endocardial LAPW isolation exists. Relative success in comparison to PVI alone has been mixed. The hybrid convergent procedure was developed to combine minimally invasive surgical and electrophysiology techniques to accomplish effective PVI and LAPW isolation. Epicardial LAPW isolation is performed by a cardiothoracic surgeon followed by endocardial ablation by an electrophysiologist who ensures PVI completion and targets any remaining gaps. Safety and effectiveness of hybrid convergent was evaluated in the prospective, multi-center, randomized controlled trial, Convergence of Epicardial and Endocardial Ablation for the Treatment of Symptomatic Persistent AF (CONVERGE). CONVERGE compared the effectiveness of the hybrid convergent procedure to endocardial catheter ablation for treatment of drug-refractory persistent and longstanding persistent AF and demonstrated primary effectiveness of higher freedom from atrial arrhythmias absent new/increased dose previously failed/intolerant anti-arrhythmic drugs through 12 months compared to endocardial catheter ablation. Greater freedom from AF and proportion of patients experiencing ≥90% burden reduction with hybrid convergent ablation were seen through 18 months follow-up. Improved electrophysiology lab efficiency was demonstrated by the reduction in endocardial ablation time with addition of epicardial ablation. This multi-disciplinary heart team procedure may improve outcomes in difficult-to-treat patients with advanced AF. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 14 Apr 2022; epub ahead of print

Radiofrequency ablation- to insure or not to insure is the question.

Sanghai S, Henrikson CA
Radiofrequency (RF) remains the most used energy source for cardiac ablation since its initial clinical use in 1985 mainly because of its ability to create targeted, discrete areas of irreversible coagulation necrosis while maintain safety and patient comfort This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Apr 2022; epub ahead of print

Efficacy and safety of High Power Short Duration atrial fibrillation ablation in elderly patients.

Müller J, Nentwich K, Berkovitz A, Ene E, ... Akin I, Deneke T
Background
Data about atrial fibrillation (AF) ablation using high power short duration (HPSD) radiofrequency ablation in the elderly population is still scarce. The aim of our study was to investigate the efficacy and safety of HPSD ablation in patients over 75 years compared to younger patients.
Methods
Consecutive patients older than 75 years with paroxysmal or persistent AF undergoing a first time AF ablation using 50W HPSD ablation approach were analysed in this retrospective observational analysis and compared to a control group <75 years. Short-term endpoints included intraprocedural reconnection of at least one PV, intrahospital and AF recurrence during 3 months blanking period as well as long-term endpoint of freedom from atrial arrhythmias of antiarrhythmic drugs after 12 months.
Results
A total of 540 patients underwent a first AF ablation with HPSD (66 ± 10 years; 58% male; 47% paroxysmal AF). Mean age was 78 ± 2.4 years and 63 ± 6.3 years (p<0.001), respectively. Elderly patients were significantly more often women (p<0.001). Procedure, fluoroscopy and ablation were comparable. Elderly patients revealed significantly more often extra-PV low voltage areas requiring additional left atrial ablations (p<0.001). Overall complication rates were low, however elderly patients revealed higher major complication rates mainly due to unmasking sick sinus syndrome (p=0.003). Freedom from arrhythmia recurrences was comparable (68% vs. 76%, log-rank p=0.087). Only in the subgroup of paroxysmal AF AF recurrences were more common after 12 months (69% vs. 82%; log-rank p=0.040; HR 1.462, p=0.044) in the elderly patients. In multivariable Cox regression analysis of the whole cohort persistent AF, female gender, diabetes mellitus and presence of LA low-voltage areas, but not age > 75 years were associated with AF recurrences.
Conclusions
HPSD AF ablation of patients >75 years in experienced centres is safe and effective. Therefore, age alone should not be the reason to withhold AF ablation from vital elderly patients due to only slightly worse outcome and safety profile. In paroxysmal AF elderly patients have more recurrences compared to the younger control group. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Apr 2022; epub ahead of print

Low-voltage areas identified with new mapping catheters and technologies.

Miyazaki S
The development of the electroanatomic mapping technology has allowed us to precisely localize the mapping catheter and recorded electroanatomic information in a 3-dimensional (3D) field. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Apr 2022; epub ahead of print

Step by Step: How to perform a fluoroless cryoballoon ablation for atrial fibrillation.

Alyesh D, Frederick J, Choe W, Sundaram S
Pulmonary vein isolation (PVI) is the cornerstone of ablation of atrial fibrillation. With widespread use of 3D Electroanatomic Mapping Systems and advances in Intracardiac Echo (ICE) imaging, fluoroless ablation has been possible. Fluoroless ablation with cryoballoon (CB), however, has not been widely performed because of the need to prove occlusion of the vein with contrast dye and fluoroscopy. In this step-by-step guide, the authors will show how a CB ablation can be performed without the use of fluoroscopy. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Apr 2022; epub ahead of print

Case Volume and Procedural Outcomes in Ablation for Atrial Fibrillation: Practice Makes Perfect?

Muthalaly RG, John RM
Ablation for atrial fibrillation (AF) is an established therapy that continues to grow in scope and indication This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Apr 2022; epub ahead of print

Pro-arrhythmia with Anti-arrhythmic Drugs in Patients with Idiopathic Ventricular Arrhythmia: A Common Problem with Vague Definitions and Complex Interactions.

Hasdemir C, Payzin S
Universally accepted, well-described definitions for therapeutic efficacy and pro-arrhythmia with AADs among patients with IVAs are lacking. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 21 Apr 2022; epub ahead of print

Influence of respiration and tissue contact on ventricular substrate identification during high density mapping: results from an ovine infarct model.

Campbell T, Bennett RG, Anderson RD, Turnbull S, Kumar S
Introduction
Multi-electrode mapping (MEM) and automated point collection are important enhancements to substrate mapping in ventricular tachycardia ablation. The effects of tissue contact and respiration on electrogram voltage with differing depolarisation wavefronts with MEM catheters are unclear.
Methods
Bipolar and unipolar voltages were collected from control (n=5) and infarcted (n=7) animals with a multi-spline MEM catheter. Electro-anatomic maps were created in sinus rhythm, and right and left ventricular pacing. Analysis was performed across three collection settings: standard (SS), respiratory-phase gating (RG), and electrode-tissue proximity (TP). Comparison was made to scar detected by cardiac MRI (cMRI).
Results
Compared to SS and RG acquisition, median bipolar and unipolar voltages were higher using TP, regardless of the depolarization wavefront. In infarct animals, bipolar voltages were 30.7-50.5% higher for bipolar and 8.7-13.8% higher on unipolar voltages with TP, compared to SS. The effect of RG on bipolar and unipolar voltages was minimal. Percentage of local abnormal ventricular activities was not impacted by acquisition settings or wavefront direction in infarct animals. Compared with cMRI defined scar, all three acquisition settings overestimated scar area using standard voltage-based cutoffs. RG improved the low voltage area concordance with MRI by 1.6-5.1% whereas TP improved by 5.9-8.4%.
Conclusions
High density voltage mapping with a MEM catheter is influenced by point collection settings. Tissue contact filters reduced low voltage areas and improved agreement with cMRI fibrosis in infarcted ovine hearts. These findings have critical implications for optimising filter settings for high density substrate mapping in the left ventricle. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 07 Apr 2022; epub ahead of print

Systematic review of electrophysiology procedures in patients with obstruction of the inferior vena cava.

Al-Sinan A, Dip Cardiac G, Chan KH, Young GD, ... Sepahpour A, Sy RW
Aims
The objective of the study was to conduct a systematic review to describe and compare the different approaches for performing cardiac electrophysiology (EP) procedures in patients with interrupted inferior vena cava (IVC) or equivalent entities causing IVC obstruction.
Methods
We conducted a structured search to identify manuscripts reporting electrophysiology (EP) procedures with interrupted IVC or IVC obstruction of any aetiology published up until August 2020. No restrictions were applied in the search strategy. We also included 7 local cases that met inclusion criteria.
Results
The analysis included 142 patients (mean age 48.9y; 48% female) undergoing 143 procedures. Obstruction of the IVC was not known before the index procedure in 54% of patients. Congenital interruption of IVC was the most frequent cause (80%); and, associated congenital heart disease (CHD) was observed in 43% of patients in this setting. The superior approach for ablation was the most frequently used strategy (52%), followed by inferior approach via the azygos or hemiazygos vein (24%), transhepatic approach (14%), and retroaortic approach (10%). Electroanatomical mapping (58%), use of long sheaths (41%), intracardiac echocardiography (19%), transesophageal echocardiography (15%) and remote controlled magnetic navigation (13%) were used as adjuncts to aid performance. Ablation was successful in 135 of 140 procedures in which outcomes were reported. Major complications were only reported in patients undergoing AF ablation, including two patients with pericardial effusion, one of whom required surgical repair, and another patient who died after inadvertent entry into an undiagnosed atrioesophageal fistula from a previous procedure.
Conclusion
The superior approach is most frequent approach for performing EP procedures in the setting of obstructed IVC. Transhepatic approach is a feasible alternative, and may provide a \'familiar approach\' for transseptal access when it is required. Adjunctive use of long sheaths, intravascular echocardiography, electro-anatomical mapping and remote magnetic navigation may be helpful, especially if there is associated complex CHD. With careful planning, EP procedures can usually be successfully performed with a low risk of complications. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 20 Apr 2022; epub ahead of print

Ripple Mapping: A precise tool for atrioventricular nodal reentrant tachycardia ablation.

Howard TS, Valdes SO, Zobeck MC, Lam WW, ... Dan Pham T, Kim JJ
Introduction
Ablation for atrioventricular nodal reentrant tachycardia (AVNRT) classically utilizes evaluation of signal morphology within the anatomic region of the slow pathway (SP), which involves subjectivity. Ripple Mapping (RM) (CARTO-3© Biosense Webster Inc, Irvine, CA) displays each electrogram at its 3-dimensional coordinate as a bar changing in length according to its voltage-time relationship. This allows prolonged, low-amplitude signals to be displayed in their entirety, helping identify propagation in low-voltage areas. We set out to evaluate the ability of RM to locate the anatomic site of the slow pathway and assess its use in guiding ablation for AVNRT.
Methods
Patients ≤18 yrs with AVNRT in the EP laboratory between 2017 and 2021 were evaluated. RM was performed to define region of SP conduction in patients from 2019-2021, whereas standard electro-anatomical mapping was used from 2017-2019. All ablations were performed using cryo-therapy. Demographics, outcomes and analysis of variance in number of test lesions until success were compared between groups.
Results
A total 115 patients underwent AVRNT ablation during the study; 46 patients were in the RM group and 69 were in the control group. There were no demographic differences between groups. All procedures, in both groups, were acutely successful. In RM group, 89% of first successful lesions were within 4mm of the predicted site. There was significantly reduced variability in number of test lesions until success in the RM group (p=0.01).
Conclusions
RM is a novel technique that can help identify slow pathway location, allowing for successful ablation of AVNRT with decreased variability. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 13 Apr 2022; epub ahead of print

The Impact of Hospital Case Volume on the Outcomes after Catheter Ablation for Atrial Fibrillation according to the Ablation Technology.

Kanaoka K, Nishida T, Nishioka Y, Myojin T, ... Imamura T, Saito Y
Introduction
The appropriate hospital case volume for catheter ablation (CA) in patients with atrial fibrillation (AF) according to the ablation technology has not been fully examined. This study aimed to investigate the association between the hospital case volume for AF and peri-procedural complications and AF recurrence.
Methods
In this retrospective cohort study, we used data from the National Database of Health Insurance Claims and Specific Health Checkups, which covers almost all healthcare insurance claims data in Japan. We included patients with AF who underwent first-time CA from April 2014 to March 2020. Using mixed-effect logistic regression, we analyzed the effect of the annual case volume for AF ablation on acute periprocedural complications and one-year success rate off antiarrhythmic drugs according to the ablation technology (radiofrequency ablation or cryoballoon ablation).
Results
Among 270,116 patients, 207,839 (77%) patients underwent radiofrequency ablation and 56,648 (21%) patients underwent cryoballoon ablation. Of all patients, acute complications occurred in 5,411 (2.0%) patients, and the recurrence at 1 year was 71,511 (27%). In the radiofrequency ablation group, acute complications and one-year AF recurrence according to case volume decreased as the annual case volume increased to up to 150-200 cases/year. However, in the cryoballoon ablation group, these outcomes were similar regardless of the case volumes.
Conclusion
The case-volume effect was noted in the radiofrequency ablation group, but not in the cryoballoon ablation group. Our results may affect the selection of ablation technology, especially in smaller case-volume hospitals. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 Apr 2022; epub ahead of print

Early repolarization syndrome, epilepsy, and atrial fibrillation in a young girl with novel KCND3 mutation managed with quinidine.

Choubey M, Bansal R, Siddharthan D, Naik N, Sharma G, Saxena A
A 6-year-old girl presented with a difficult to control epilepsy syndrome. On evaluation, additional presyncope episodes associated with polymorphic ventricular tachycardia were also noted. A diagnosis of early repolarization syndrome (ERS) was made with an early repolarization pattern on electrocardiogram, documented VT episodes, and clinical presyncope (proposed Shanghai score 7). Paroxysmal atrial fibrillation (AF) was also noted on 24-h Holter recordings. The child was stabilized with isoprenaline infusion and was later discharged with arrhythmia control on quinidine and cilostazol. The genetic evaluation revealed a potassium channel KCND3 gene missense mutation. The case highlights the association of epilepsy syndrome and AF with ERS; the possible association of KCND3 gene mutation with a malignant phenotype; and management issues in a small child.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 07 Apr 2022; epub ahead of print

Cardioneuroablation for vasovagal syncope and atrioventricular block: A step-by-step guide.

Aksu T, Gupta D, D\'Avila A, Morillo CA
Catheter-based cardioneuroablation is increasingly being utilized to improve outcomes in patients with vasovagal syncope and atrioventricular block due to vagal hyperactivity. There is now increasing convergence among enthusiasts on its various aspects, including patient selection, technical steps, and procedural end-points. This pragmatic review aims to take the reader through a step-by-step approach to cardioneuroablation: we begin with a brief overview of the anatomy of intrinsic cardiac autonomic nervous system, before focusing on the indications, preprocedure and postprocedure management, necessary equipment, and its potential limitations.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 01 Apr 2022; epub ahead of print

Ventricular tachycardia targeted in the aortic sinuses of Valsalva in patients with prior myocardial infarction.

Siontis KC, Njeim M, Dabbagh GS, Yokokawa M, Morady F, Bogun F
Introduction
Ventricular tachycardia (VT) in structurally normal hearts or nonischemic cardiomyopathy can originate from the aortic sinuses of Valsalva (SoV). It is unknown whether VT can originate from the SoVs in patients with prior myocardial infarction (MI).
Objective
To evaluate the prevalence, arrhythmogenic substrate, and ablation outcomes of postinfarction VT originating from the SoVs.
Methods
Among 217 consecutive patients with postinfarction VT undergoing ablation, we identified 13 (6%) patients who had ≥1 VT mapped in a SoV. Control groups of 13 patients with idiopathic SoV VT and 13 postinfarction patients without SoV VT were included.
Results
In the study group, 17 VTs were mapped in a SoV (right n = 5, left-right commissure n = 6, left n = 6). SoV VT target sites had low bipolar voltage during sinus rhythm [median 0.42 (IQR: 0.16-0.53) mV] which was significantly lower than target sites in patients with idiopathic SoV VTs [median 1.02 (IQR: 0.89-1.52) mV; p < .001]. An area of endocardial low voltage was found below the aortic valve in all patients with postinfarction SoV VTs compared to 9 (69%) of the patients in the postinfarction control group without SoV VT (p = .02). Morphology characteristics of postinfarction SoV VTs differed from idiopathic SoV VTs. None of the postinfarction SoV VTs were inducible after ablation and none recurred after a median follow-up of 14 months.
Conclusion
In patients with prior MI, VT can be targeted in an aortic SoV. The SoVs should be routinely investigated in postinfarction patients with inferior axis VT and an area of low voltage below the aortic valve.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 06 Apr 2022; epub ahead of print

Mexiletine effectively prevented refractory Torsades de Pointes and ventricular fibrillation in a patient with congenital type 2 long QT syndrome.

Nakashima R, Takase S, Kai K, Sakamoto K, Tsutsui H
We report a 28-year-old female patient with congenital type 2 long QT syndrome (LQTS) in which mexiletine shortened QTc and effectively prevented refractory Torsade de Pointes (TdP) and ventricular fibrillation (VF). She developed TdP and VF, and was subsequently diagnosed as congenital type 2 LQTS type 2. She had refractory TdP and VF every day despite medical therapy including β-blocker. They were completely suppressed after the initiation of mexiletine with shorting of QTc interval. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 Apr 2022; epub ahead of print

Computed tomography imaging-identified location and electrocardiographic characteristics of left bundle branch area pacing in bradycardia patients.

Chen K, Liu XB, Hou X, Qiu Y, ... Cheng A, Zou J
Introduction
Left bundle branch area pacing (LBBAP) is a novel physiological pacing modality. The relationship between the pacing lead tip location and paced electrocardiographic (ECG) characteristics remains unclear. The objectives are to determine the lead tip location within the interventricular septum (IVS) and assess the location-based ECG QRS duration (QRSd) and left ventricular activation time (LVAT).
Methods
This multi-center study enrolled 50 consecutive bradycardia patients who met pacemaker therapy guidelines and received LBBAP implantation via the trans-ventricular septal approach. After at least 3 months post implant, 12-lead ECGs and pacing parameters were obtained. Cardiac computed tomography (CT) imaging was performed to assess the LBBAP lead tip distance from the LV blood pool.
Results
Among the 50 patients, analyzable CT images were obtained in 42. In 23 of the 42 patients, the lead tips were within 2 mm to the LV blood pool (the LV subendocardial (LVSE) group), 13 between 2 mm and 4 mm (the Near-LVSE group), and the remaining 6 beyond 4 mm (the mid-LV septal (Mid-LVS) group). No significant differences in paced QRSd were found among the 3 groups (LVSE, 107±15 ms; Near-LVSE, 106±13 ms; Mid-LVS, 104±15 ms; P=0.87). LVAT in the LVSE (64±7 ms) was significantly shorter than in the Mid-LVS (72±8 ms; P<0.05), but not significantly different from that in the Near-LVSE (69±8 ms; P>0.05).
Conclusion
In routine LBBAP practice, paced narrow QRSd and fast LVAT, indicative of physiological pacing, was consistently achieved for lead tip location in the LV subendocardial or near LV subendocardial region. This article is protected by copyright. All rights reserved.

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J Cardiovasc Electrophysiol: 13 Apr 2022; epub ahead of print

Predictors of appropriate implantable cardiac defibrillator therapy in cardiac sarcoidosis.

Mathijssen H, Bakker ALM, Balt JC, Akdim F, ... Grutters JC, Post MC
Background
Cardiac sarcoidosis (CS) is associated with an increased risk for sudden cardiac death. An implantable cardiac defibrillator (ICD) is recommended in a subgroup of CS patients. However, the recommendations for primary prevention differ between guidelines. The purpose of the study was to evaluate the efficacy and safety of ICDs in CS and to identify predictors of appropriate therapy.
Methods
A retrospective cohort study was performed in CS patients with an ICD implantation between 2010 and 2019. Primary outcome was appropriate ICD therapy. Independent predictors were calculated using Cox proportional hazard analysis.
Results
105 patients were included. An ICD was implanted for primary prevention in 79%. During a median follow-up of 2.8 years, 34 patients (32.4%) received appropriate ICD therapy of whom 24 (22.9%) received an appropriate shock. Three patients (2.9%) received an inappropriate shock due to atrial fibrillation. Independent predictors of appropriate therapy included prior ventricular arrhythmias (hazard ratio [HR]: 10.5 [95% confidence interval (CI): 5.0-21.9]) and right ventricular late gadolinium enhancement (LGE) (HR: 3.6 [95% CI: 1.7-7.6]). Within the primary prevention group, right ventricular LGE (HR: 5.7 [95% CI: 1.6-20.7]) was the only independent predictor of appropriate therapy. Left ventricular ejection fraction did not differ between patients with and without appropriate therapy (44.4% vs. 45.6%, p = .70).
Conclusion
In CS patients with an ICD, a high rate of appropriate therapy was observed and a low rate of inappropriate shocks. Prior ventricular arrhythmias and right ventricular LGE were independent predictors of appropriate therapy.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 11 Apr 2022; epub ahead of print

The role of cardiac surgeon in transvenous lead extraction: experience from 3462 procedures.

Tułecki Ł, Czajkowski M, Targońska S, Polewczyk A, ... Nowosielecka D, Kutarski A
Introduction
The professional society guidelines recommend that transvenous lead extraction (TLE) operating teams collaborate closely with cardiac surgeons in the management of life-threatening complications.
Methods and results
We assessed the role of cardiac surgeons participating in 3462 TLE procedures at a high-volume center between 2006 and 2021. The roles for cardiac surgery in TLE can be categorized into five areas: emergency surgical interventions for the management of cardiac laceration and severe bleeding (1.184%), cardiac surgery complementing partially successful TLE or vegetation removal (0.693%), delayed surgical treatment of TLE-related tricuspid valve dysfunction (0.751%), epicardial pacemaker implantation through sternotomy during emergency, complementing or delayed surgical interventions (0.607%) and delayed epicardial lead implantation (0.491%). Isolated damage to the wall of the right atrium was the most common cause of cardiac tamponade (53.66% of emergency surgeries) followed by injury to the right ventricle and vena cava (both 7.317%).
Conclusions
Emergency cardiac surgery for the management of severe hemorrhagic complications is still the most common treatment option. The remaining areas include surgery complementing partially successful TLE: repair of tricuspid valve or epicardial ventricular lead placement to achieve permanent cardiac resynchronization. The experience at a single high-volume TLE center indicates the necessity of close collaboration with the cardiac surgeons whose roles appear broader than the mere surgical standby. Mortality in patients who survived cardiac surgery during transvenous lead extraction does not differ from the survival of other patients after TLE without complications requiring surgical intervention. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 27 Apr 2022; epub ahead of print

Impact of body mass index on cryoablation of atrial fibrillation: Patient characteristics, procedural data, and long-term outcomes.

Urbanek L, Bordignon S, Chen S, Bologna F, ... Schmidt B, Chun KJ
Introduction
Ablation of atrial fibrillation in the context of obesity can be challenging. We sought to evaluate the role of cryoballoon pulmonary vein isolation (CB-PVI) in obese patients with symptomatic atrial fibrillation (AF).
Methods
Patients with a BMI ≥ 25 kg/m² and symptomatic AF who underwent CB-PVI were retrospectively enrolled. Three groups were defined (G1: BMI of 25-29 kg/m² ; G2: BMI of 30-34 kg/m² ; G3: BMI ≥ 35 kg/m² ).
Results
600 patients were included (59% male; 66 ± 11 years old); 337, 149, and 114 were assigned to G1, G2, and G3, respectively. Acute procedural success was recorded in 99.7% of patients. Procedural and fluoroscopy time were comparable but the radiation dose was significantly higher in G3. Procedural complications were 3% in G1, 5.4% in G2, and 8.8% in G3 (p = .01). The overall freedom from AF after 1-year was 77%. G3 had a significantly worse 1-year success rate compared to G1 and G2 (G3: 66.5% vs. G1: 78.4%; p = .015 and vs. G2: 82.5%; p = .008) with reduced 1-year success in paroxysmal AF (G1: 84.0%; G2: 86.3%; and G3: 69.6%) but not in persistent AF (G1: 68.7%; G2: 77.4%; and G3: 62.1%). G3 showed similar success rates irrespective of AF form (PAF: 69.6% vs. persAF 62.1%; p = .501).
Conclusion
Cryoballoon ablation in obese patients can be effective with an acceptable safety profile, 77% of patients were in stable SR at 1 year. Severe obese patients (BMI ≥ 35) showed reduced procedural safety and 1-year success rate. In association with life style modification, CB ablation may represent a strategy to enhance rhythm control in the context of obesity.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 30 Mar 2022; epub ahead of print

Chest computer tomography is safe without additional interrogation or monitoring for modern cardiac implantable electrical devices.

Tsutsui K, Kato R, Mori H, Kawano D, ... Muramatsu T, Matsumoto K
Introduction
Whether diagnostic computed tomography (CT) scans to cardiac implantable electronic devices (CIED) is safe in recent models remains unknown.
Methods
A two-centers observational study. Over 14 years, consecutive 2362 chest CT scans (1666 pacemakers [PMs], 145 cardiac resynchronization therapy PM, 316 implantable cardioverter-defibrillator, and 233 cardiac resynchronization therapy defibrillator) were interrogated and monitored upon imaging.
Results
Electromagnetic interference occurred only in a few old models: InSync 8040 (n = 14), InSync III Marquis (n = 1), and Kappa (n = 4), which resulted no adverse events.
Conclusion
CIEDs, especially recent ones, are confirmed safe on chest CT.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 28 Mar 2022; epub ahead of print

Longitudinal QT stability and impact of baseline cardiac rhythm on discharge dose in dofetilide-treated patients.

Khan ZA, LaBreck ME, Luli J, Roberts C, ... Amin AK, Chopra N
Introduction
Dofetilide suppresses atrial fibrillation (AF) in a dose-dependent fashion. The protective effect of AF against QT_c prolongation induced torsades de pointe and transient post-cardioversion QT_c prolongation may result in dofetilide under-dosing during initiation. Thus, the optimal timing of cardioversion for AF patients undergoing dofetilide initiation to optimize discharge dose remains unknown as does the longitudinal stability of QT_c . The purpose of this study was to evaluate the impact of baseline rhythm on dofetilide dosing during initiation and assess the longitudinal stability of QT_c-all (Bazzett, Fridericia, Framingham, and Hodges) over time.
Methods
Medical records of patients who underwent preplanned dofetilide loading at a tertiary care center between January 2016 and 2019 were reviewed.
Results
A total of 198 patients (66 ± 10 years, 32% female, CHADS₂ -Vasc 3 [2-4]) presented for dofetilide loading in either AF (59%) or sinus rhythm (SR) (41%). Neither presenting rhythm, nor spontaneous conversion to SR impacted discharge dose. The cumulative dofetilide dose before cardioversion moderately correlated (r = .36; p = .0001) with discharge dose. Postcardioversion QT_c-all prolongation (p < .0001) prompted discharge dose reduction (890 ± 224 mcg vs. 552 ± 199 mcg; p < .0001) in 30% patients. QT_c-all in SR prolonged significantly during loading (p < .0001). All patients displayed QT_c-all reduction (p < .0001) from discharge to short-term (46 [34-65] days) that continued at long-term (360 [296-414] days) follow-ups. The extent of QT_c-all reduction over time moderately correlated with discharge QT_c-all (r = .54-0.65; p < .0001).
Conclusion
Dofetilide initiation before cardioversion is equivalent to initiation during SR. Significant QT_c reduction proportional to discharge QT_c is seen over time in all dofetilide-treated patients. QT_c returns to preloading baseline during follow-up in patients initiated in SR.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 01 Apr 2022; epub ahead of print

Strategy for repeat procedures in patients with persistent atrial fibrillation: Systematic linear ablation with adjunctive ethanol infusion into the vein of Marshall versus electrophysiology-guided ablation.

Nakashima T, Pambrun T, Vlachos K, Goujeau C, ... Jaïs P, Derval N
Introduction
The optimal strategy after a failed ablation for persistent atrial fibrillation (perAF) is unknown. This study evaluated the value of an anatomically guided strategy using a systematic set of linear lesions with adjunctive ethanol infusion into the vein of Marshall (Et-VOM) in patients referred for second perAF ablation procedures.
Methods and results
Patients with perAF who underwent a second procedure were grouped according to the two strategies. The first strategy was an anatomically guided approach using systematic linear ablation with adjunctive Et-VOM, with bidirectional blocks at the posterior mitral isthmus (MI), roof, and cavotricuspid isthmus (CTI) as the procedural endpoint (Group I). The second one was an electrophysiology-guided strategy, with atrial tachyarrhythmia termination as the procedural endpoint (Group II). Arrhythmia behavior during the procedure guided the ablation strategy. Groups I and II consisted of 96 patients (65 ± 9 years; 71 men) and 102 patients (63 ± 10 years; 83 men), respectively. Baseline characteristics were comparable. In Group I, Et-VOM was successfully performed in 91/96 (95%), and procedural endpoint (bidirectional block across all three anatomical lines) was achieved in 89/96 (93%). In Group II, procedural endpoint (atrial tachyarrhythmia termination) was achieved in 80/102 (78%). One-year follow-up demonstrated Group I (21/96 [22%]) experienced less recurrence compared to Group II (38/102 [37%], Log-rank p = .01). This was driven by lower AT recurrence in Group I (Group I: 10/96 [10%] vs. Group II: 29/102 [28%]; p = .002).
Conclusion
Anatomically guided strategy with adjunctive Et-VOM is superior to an electrophysiology-guided strategy for second procedures in patients with perAF at 1-year follow-up.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 28 Mar 2022; epub ahead of print

Is prophylactic ablation of the cavotricuspid and peri-incisional isthmus justified in patients with postoperative atrial flutter after right atriotomy?

Benak A, Kupo P, Bencsik G, Makai A, Saghy L, Pap R
Background
The two most common postoperative atrial flutter (AFL) circuits after right atriotomy are the cavotricuspid isthmus (CTI) dependent and the lateral, peri-incisional. We investigated whether radiofrequency ablation (RFA) of both circuits results in more favorable long-term outcomes.
Methods
Single-center retrospective cohort study of consecutive patients who underwent RFA of AFL after open-heart surgery. The effect of surgery type and RFA strategy on AFL recurrence was evaluated.
Results
One hundred and forty-two patients (mean age 64.5 ± 12.7 years, 65.% male) were enrolled. Patients with right atrial (RA) flutter (n = 124) were divided into two groups based on the index RFA procedure: only one RA circuit was ablated (Group 1, n = 84, 67.7%) or both the CTI and the peri-incisional circuit ablated (Group 2, n = 40, 32.3%). The previous open-heart surgery was categorized based on the extension of the RA incision: limited (Type A) or extended (Type B) atriotomy. After a mean follow-up of 36 ± 28 months, flutter recurrence was not different among patients with limited RA atriotomy (25% vs. 22% in Groups 1A and 2A, respectively, p = 1.0). However, after type B surgery, ablation of both AFL circuits was associated with a reduced recurrence rate (63% vs. 26% in Groups 1B and 2B, respectively, p = .002).
Conclusions
In patients with postoperative RA flutter after extended right atriotomy, ablation of both the CTI and the peri-incisional isthmus significantly reduces the AFL recurrence rate. Prophylactic ablation of both isthmi, even if not proven to support reentry, is reasonable in this population.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 31 Mar 2022; epub ahead of print

Clinical Outcomes Of Left Bundle Branch Area Pacing Compared To His Bundle Pacing.

Vijayaraman P, Rajakumar C, Naperkowski AM, Subzposh FA
Background
His bundle pacing (HBP) is the most physiologic form of pacing and has been associated with reduced risk for heart failure hospitalization (HFH) and mortality compared to right ventricular pacing. Left bundle branch area pacing (LBBAP) is a safe and effective alternative option for patients needing ventricular pacing.
Objective
The aim of this study was to compare the clinical outcomes between LBBAP and HBP among a large cohort of patients undergoing permanent pacemaker implantation.
Methods
This observational registry included consecutive patients with AV block/AV node ablation who underwent de novo permanent pacemaker implantations with successful LBBAP or HBP between April 2018 to October 2020. The primary outcome was the composite endpoint of time to death from any cause or HFH. Secondary outcomes included the composite endpoint among patients with prespecified ventricular pacing burden and individual outcomes.
Results
The study population included 359 patients who met the inclusion criteria (163 in the HBP and 196 in the LBBAP group). Paced QRSd during LBBAP was similar to HBP (125 ± 20.2 vs 126 ± 23.5 ms, p=0.643). There were no statistically significant differences in the primary composite outcome in LBBAP (17.3%) compared to HBP (24.5%) (HR 1.15, CI 0.72-1.82, p = 0.552). Secondary outcomes of death (10 vs 17%; HR 1.3, CI 0.73-2.33, p=0.38) and HFH (10 vs 12%; HR 1.02,CI 0.54-1.94, p=0.94) were not different among both groups.
Conclusions
There were no statistically significant differences in the clinical outcomes of death or HFH in LBBAP when compared to HBP. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 Apr 2022; epub ahead of print

A case series of very slow atrioventricular nodal reentrant tachycardia resembling junctional tachycardia.

Higuchi K, Higuchi S, Baranowski B, Wazni O, Scheinman MM, Tchou P
Introduction
The surface electrocardiography of typical atrioventricular nodal reentrant tachycardia (AVNRT) shows simultaneous ventricular-atrial (RP) activation with pseudo R\' in V1 and typical heart rates ranging from 150 to 220/min. Slower rates are suspicious for junctional tachycardia (JT). However, occasionally we encounter typical AVNRT with slow ventricular rates. We describe a series of typical AVNRT cases with heart rates under 110/min.
Methods
A total of 1972 patients with AVNRT who underwent slow pathway ablation were analyzed. Typical AVNRT was diagnosed when; (1) evidence of dual atrioventricular nodal conduction, (2) tachycardia initiation by atrial drive train with atrial-His-atrial response, (3) short septal ventriculoatrial time, and (4) ventricular-atrial-ventricular (V-A-V) response to ventricular overdrive (VOD) pacing with corrected post pacing interval-tachycardia cycle length (cPPI-TCL) > 110 ms. JT was excluded by either termination or advancement of tachycardia by atrial extrastimuli (AES) or atrial overdrive (AOD) pacing.
Results
We found 11 patients (age 20-78 years old, six female) who met the above-mentioned criteria. The TCL ranged from 560 to 782 ms. Except for one patient showing tachycardia termination, all patients demonstrated a V-A-V response and cPPI-TCL over 110 ms with VOD. AES or AOD pacing successfully excluded JT by either advancing the tachycardia in 10 patients or by tachycardia termination in one patient. Slow pathway was successfully ablated, and tachycardia was not inducible in all patients.
Conclusions
This case series describes patients with typical AVNRT with slow ventricular rate (less than 110/min) who may mimic JT. We emphasize the importance of using pacing maneuvers to exclude JT.

© 2022 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 29 Mar 2022; epub ahead of print

Optimal ablation strategy for arrhythmia recurrence following persistent atrial fibrillation ablation; anatomy or electrophysiology?

Choudhury M, Mahida S
The optimal strategy for ablation of persistent atrial fibrillation (PsAF) remains to be defined. Established substrate-based ablation techniques, particularly techniques targeting complex electrograms, with complementary linear ablation for organized atrial tachycardias, have been associated with modest success rates. Recently, the development of VoM ethanol ablation (Et-VoM) has facilitated ablation of previously inaccessible arrhythmogenic substrate. This has allowed comparison of a standardized anatomically-guided protocol with Et-VOM to a traditional electrophysiology-guided approach for PsAF ablation.

© 2022 Wiley Periodicals LLC.

J Cardiovasc Electrophysiol: 28 Mar 2022; epub ahead of print

Initial clinical experience of pulmonary vein isolation using the ultra-low temperature cryoablation catheter for patients with atrial fibrillation.

Tohoku S, Schmidt B, Bordignon S, Chen S, Bologna F, Julian Chun KR
Background
The iCLAS ultra-low temperature cryoablation (ULTC) system has recently brought to the market. A combination of a newly exploited cryogen and interchangeable stylet enables flexible and continuous lesion creation in atrial fibrillation (AF) ablation. The use of an esophageal warming balloon is recommended when using the system to reduce the potential for collateral esophageal injury.
Objective
To describe the initial clinical experience when using ULTC in the AF treatment without general anesthesia (GA).
Methods
Consecutive patients undergoing AF ablation using ULTC under deep sedation without GA were enrolled. We assessed the procedural data focusing on \"single-shot isolation\" defined as successful pulmonary vein (PV) isolation after the first application. Esophagogastroduodenoscopy was systematically performed the day after ablation.
Results
A total of 27 AF patients (67% paroxysmal AF) were analyzed. One-hundred-four out of 106 PVs (98.1%) were isolated solely using ULTC. The mean procedure time was 79 ± 30 min. The mean number of applications per PV was 2.6 ± 1.0. Single-shot isolation was achieved in 57 PVs (54%) varying across PVs from left superior- to inferior PVs (40-64%). Single procedure six-month recurrence free rate was 84%. No major complication (cerebrovascular event, pericardial effusion/tamponade, esophageal damage on esophagogastroduodenoscopy) occurred. A single transient phrenic nerve palsy occurred during the right superior PV ablation which had recovered by the 3-month follow up appointment.
Conclusions
AF ablation using the novel ULTC system seemed feasible without GA and enabled >50% single-shot isolation rate. The promising safety profile has to be confirmed in large-scaled studies. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 Apr 2022; epub ahead of print

A frozen decade: Ten years outcome after cryoballoon pulmonary vein isolation.

Rottner L, Metzner A
Cryoballoon (CB) ablation has emerged as an established gold standard for PVI. Since its introduction into clinical practice, more than one million patients worldwide suffering from symptomatic AF have been treated with different versions of this first real single-shot device. High acute and midterm clinical success, a very beneficial safety profile, short learning curves and high procedural reproducibility are strongly associated with CB guided PVI. Though there is a great amount of data on acute efficacy and short- as well as midterm clinical outcome available, studies reporting on long-term arrhythmia-free survival and on long-term safety of CB-PVI is lacking. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 Apr 2022; epub ahead of print

Frozen, Gone in 60 Seconds!

Saouma S, Kowalski M
The field of electrophysiology has seen the development of a novel ultralow temperature cryoablation (ULTC) system. The data presented in this manuscript shows that the ULTC system is feasible, safe, and effective in acute PVI under sedation and by using angiography only This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 Apr 2022; epub ahead of print

The Development of the Extravascular Defibrillator with Substernal Lead Placement: A New Frontier for Device-Based Treatment of Sudden Cardiac Arrest.

Thompson AE, Atwater B, Boersma L, Crozier I, ... Kuschyk J, DeGroot P
Introduction
The extravascular ICD (EV ICD) system with substernal lead placement is a novel non-transvenous alternative to current commercially available ICD systems. The EV ICD provides defibrillation and pacing therapies without the potential long-term complications of endovascular lead placement but requires a new procedure for implantation with a safety profile under evaluation.
Methods
This paper summarizes the development of the EV ICD, including the pre-clinical and clinical evaluations that have contributed to system and procedural refinements to date.
Results
Extensive pre-clinical research evaluations and 4 human clinical studies with >140 combined acute and chronic implants have enabled the development and refinement of the EV ICD system, currently in worldwide pivotal study.
Conclusion
The EV ICD may represent a clinically valuable solution in protecting patients from sudden cardiac death while avoiding the long-term consequences of transvenous hardware. The EV ICD offers advantages over transvenous and subcutaneous systems by avoiding placement in the heart and vasculature; relative to subcutaneous systems, EV ICD requires less energy for defibrillation, enabling a smaller device, and provides pacing features such as anti-tachycardia and asystole pacing in a single system. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 28 Apr 2022; epub ahead of print

Preliminary study on left bundle branch area pacing in children:clinical observation of 12 cases.

Wenlong D, Baojing G, Chencheng D, Jianzeng D
Objective
To explore the safety and feasibility of left bundle branch area pacing (LBBAP) in children.
Methods
This study observed 12 children attempted LBBAP from January 2019 to January 2021 in the department of pediatric cardiology of Anzhen Hospital prospectively.Clinical data, pacing parameters, electrocardiograms, intracardiac electrograms, echocardiographic measurements and complications were recorded at implant and during follow-up.
Results
The 12 patients aged between 3 and 14 years old and weighted from 13 to 48kg. Eleven patients were diagnosed with third-degree atrioventricular block and 1 patient (case 4) suffered from cardiac dysfunction due to right ventricular apical pacing (RVAP). Left bundle branch area pacing was successfully achieved in all patients with narrow QRS complexes and V₁ lead showed changes like right bundle branch block in the pacing electrocardiogram. Left ventricular ejection fraction in case 4 recovered on the 3rd day after LBBAP. The median of left ventricular end diastolic diameter Z score of the 12 patients decreased from 1.75 to1.05 3 months after implantation (p<0.05). The median of paced QRS duration was 103ms. The median of pacing threshold, R-wave amplitude and impedance were 0.85V, 15mV and 717Ω respectively and remained stable during follow-up. No complications such as loss of capture, lead dislodgement or septal perforation occurred.
Conclusions
Left bundle branch area pacing can be performed safely in children with narrow QRS duration and stable pacing parameters. Cardiac dysfunction caused by long-term RVAP can be corrected by LBBAP quickly. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 04 May 2022; epub ahead of print

Esophago-gastric Complications in Radiofrequency and Cryoballoon Catheter Ablation of Atrial Fibrillation.

Oikawa J, Fukaya H, Wada T, Kishihara J, ... Kusano C, Ako J
Background
Direct comparison studies about the incidence of esophago-gastric complications between radiofrequency (RF) and cryoballoon (CB) catheter ablation (CA) for atrial fibrillation (AF) have been scarce. We sought to elucidate the relationship between the pulmonary vein isolation (PVI) modalities and esophago-gastric complications.
Methods
The study population consisted of 254 patients who underwent CA for AF from November 2017 to October 2018. Finally, 160 patients were enrolled and divided into the RF and CB groups. Esophageal ulcers, gastric hypomotility, and exfoliative esophagitis detected by esophago-gastro-duodenoscopy were defined as esophago-gastric complications in this study.
Results
The median age was 68 years old, with 34% being females. Esophago-gastric complications were observed in 42.5% of patients who underwent CA. According to the detailed esophago-gastric complications, the RF group had a higher prevalence of esophageal ulcers than the CB group (19% vs. 0%, p <0.0001). There was no significant difference between the two groups regarding gastric hypomotility and exfoliative esophagitis (18% vs. 28%; p = 0.15, 16% vs. 21%; p = 0.42, respectively).
Conclusions
Asymptomatic esophago-gastric complications were common in catheter ablation for atrial fibrillation. The incidence of esophageal ulcers was higher in the radiofrequency group than cryoballoon group, whereas the other esophago-gastric complications did not significantly differ. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 Apr 2022; epub ahead of print

Use of extendable helix leads for conduction system pacing: differences in lead handling and performance: Conclusion.

Tan ES, Lee JY, Boey E, Soh R, ... Seow SC, Kojodjojo P
Introduction
Pacing leads with extendable-retractable helix (EHL) are alternatives to fixed-helix leads (FHL) for conduction system pacing (CSP), but data on handling characteristics are limited. This study evaluated a dual-center experience of lead handling and performance during CSP.
Methods and results
Consecutive patients with His-bundle pacing (HBP) or left bundle branch pacing (LBBP) were evaluated for the primary outcome of lead failure, defined as structural damage to the lead necessitating lead replacement. Differences in pacing characteristics were compared. Among 280 patients (mean age 74±11 years, 44% male, 50% LBBP), 246 (88%) received FHL and 34 (12%) received EHL. Of 299 leads used, lead failure occurred more frequently among patients with EHL than FHL (29% vs 2%, p<0.001), regardless of CSP modality. Majority of damaged leads (89%) in the form of helix deformation were successfully removed, with failure occurring in only 2 patients, both EHL, leading to helix fracture and retention within the septal myocardium. EHL, compared to FHL, was associated with 25-fold increased odds of lead failure (odds ratio 25.21, 95% confidence interval 7.35-86.51), and persisted after adjustment in turn for age, pacing modality and indication. CSP implant success rates did not differ by lead design (FHL 80% vs EHL 71%, p=0.18), with similar pacing thresholds at implant and follow-up. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 06 May 2022; epub ahead of print

Association between implantable defibrillator-detected sleep apnea and atrial fibrillation: the DASAP-HF study.

Boriani G, Diemberger I, Pisanò EC, Pieragnoli P, ... Ricci RP, D\'Onofrio A
Aim
The Respiratory Disturbance Index (RDI) computed by an implantable cardioverter defibrillator (ICD) algorithm accurately identifies severe sleep apnea (SA). In the present analysis we tested the hypothesis that RDI could also predict AF burden.
Methods
Patients with ejection fraction ≤35% implanted with an ICD were enrolled and followed-up for 24 months. One month after implantation, patients underwent a polysomnographic study. The weekly mean RDI value was considered, as calculated during the entire follow-up period and over a 1-week period preceding the sleep study. The endpoints were: daily AF burden of ≥5 minutes, ≥6 hours, ≥23 hours.
Results
164 patients had usable RDI values during the entire follow-up period. Severe SA (RDI≥30 episodes/h) was diagnosed in 92 (56%) patients at the time of the sleep study. During follow-up, AF burden ≥5 minutes/day was documented in 70 (43%), ≥6 hours/day in 48 (29%), and ≥23 hours/day in 33 (20%) patients. Device-detected RDI≥30 episodes/h at the time of the polygraphy, as well as the polygraphy-measured apnea hypopnea index ≥30 episodes/h, were not associated with the occurrence of the endpoints, using a Cox regression model. However, using a time-dependent model, continuously measured weekly mean RDI≥30episodes/h was independently associated with AF burden ≥5 minutes/day (HR:2.13, 95%CI:1.24-3.65, p=0.006), ≥6 hours/day (HR:2.75, 95%CI:1.37-5.49, p=0.004), and ≥23 hours/day (HR:2.26, 95%CI:1.05-4.86, p=0.037).
Conclusions
In heart failure patients, ICD-diagnosed severe SA on follow-up data review identifies patients who are from two- to three-fold more likely to experience an AF episode, according to various thresholds of daily AF burden. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 02 May 2022; epub ahead of print

Targeted ablation of residual pulmonary vein potentials in atrial fibrillation ablation through ultra-high-density mapping: insights from the CHARISMA registry.

Solimene F, Stabile G, Segreti L, Malacrida M, ... De Simone A, Garcia-Bolao I
Introduction
Low-voltage activity beyond pulmonary veins (PVs) may contribute to the failure of ablation of atrial fibrillation (AF) in the long term. We aimed to assess the presence of gaps (PVG) and residual potential (RAP) within the antral scar by means of an ultra-high density mapping (UHDM) system.
Methods
We studied consecutive patients from the CHARISMA registry who were undergoing AF ablation and had complete characterization of residual PV antral activity. The Lumipoint^TM (Boston Scientific) map-analysis tool was used sequentially on each PV component. The ablation endpoint was PV isolation (PVI) and electrical quiescence in the antral region.
Results
Fifty-eight cases of AF ablation were analyzed. A total of 86 PVGs in 34 (58.6%) patients and 44 RAPs in 34 patients (58.6%) were found. In 16 (27.6%) cases, we found at least one RAP in patients with complete absence of PV conduction. RAPs showed a lower mean voltage than PVG (0.3±0.2mV vs 0.7±0.5mV, p<0.0001), whereas the mean number of EGM peaks was higher (8.4±1.4 vs 3.2±1.5, p<0.0001). The percentage of patients in whom RAPs were detected through Lumipoint^TM was higher than through propagation map analysis (58.6% vs 36.2%, p=0.025). Acute procedural success was 100%, with all PVs successfully isolated and RAPs completely abolished in all study patients. During a mean follow-up of 453±133 days, 6 patients (10.3%) suffered an AF/AT recurrence.
Conclusion
Local vulnerabilities in antral lesion sets were easily discernible by means of the UHDM system in both de novo and redo patients when no PV conduction was present.
Clinical trial registration
Catheter Ablation of Arrhythmias with a High-Density Mapping System in Real-World Practice (CHARISMA). URL: http://clinicaltrials.gov/Identifier: NCT03793998 This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 06 May 2022; epub ahead of print

Pulsed-Field Ablation: What Are the Unknowns and When Will They Cease to Concern Us?

Steiger NA, Romero JE
Catheter ablation (CA) is the mainstay therapy for the maintenance of sinus rhythm in patients with paroxysmal and persistent atrial fibrillation (AF). This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 05 May 2022; epub ahead of print

In-vivo porcine characterization of atrial lesion safety and efficacy utilizing a circular pulsed-field ablation catheter including assessment of collateral damage to adjacent tissue in supratherapeutic ablation applications.

Hsu JC, Gibson D, Banker R, Doshi SK, ... Govari A, Natale A
Introduction
Pulsed field ablation (PFA), an ablative method that causes cell death by irreversible electroporation, has potential safety advantages over radiofrequency ablation and cryoablation. Pulmonary vein (PV) isolation was performed in a porcine model to characterize safety and performance of a novel, fully-integrated biphasic PFA system comprising a multi-channel generator, variable loop circular catheter, and integrated PFA mapping software module.
Methods
Eight healthy porcine subjects were included. To evaluate safety, multiple ablations were performed, including sites not generally targeted for therapeutic ablation, such as the right inferior PV lumen, right superior PV ostium, and adjacent to the esophagus and phrenic nerve. To evaluate efficacy, animals were recovered, followed for 30(±3) days, then re-mapped. Gross pathological and histopathological examinations assessed procedural injuries, chronic thrombosis, tissue ablation, penetration depth, healing, and inflammatory response.
Results
All 8 animals survived follow-up. PV narrowing was not observed acutely nor at follow-up, even when ablation was performed deep to the PV ostium. No injury was seen grossly or histologically in adjacent structures. All PVs were durably isolated, confirmed by bidirectional block at re-map procedure. Histological examination showed complete, transmural necrosis around the circumference of the ablated section of right PVs.
Conclusion
This pre-clinical evaluation of a fully-integrated PFA system demonstrated effective and durable ablation of cardiac tissue and PV isolation without collateral damage to adjacent structures, even when ablation was performed in more extreme settings than those used therapeutically. Histological staining confirmed complete transmural cell necrosis around the circumference of the PV ostium at 30 days. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 05 May 2022; epub ahead of print

A frozen decade: Ten years outcome of atrial fibrillation ablation using a single shot device for pulmonary vein isolation.

Bergau L, Sciacca V, Nesapiragasan V, Rubarth K, ... Sommer P, Christian Sohns MD
Aims
Cryoballoon-guided pulmonary vein isolation (CB-PVI) for symptomatic atrial fibrillation (AF) has become an established treatment option with encouraging results in terms of safety and efficacy. Data reporting on long-term data beyond a follow-up (FU) period of five years is scarce. This prospective study aimed to evaluate very long-term outcome after CB-PVI for AF.
Methods
Data from consecutive patients treated with CB-PVI for symptomatic and drug refractory AF between 2005 and 2012 were analyzed. Patients with a FU of ≥9 years after index CB-PVI were included. All patients were continuously followed-up in our outpatient clinic. Arrhythmia recurrence was defined as AF or atrial tachycardia (AT) lasting >30s beyond a three-month blanking period.
Results
A total of 385 patients (71% male) were included. Mean age was 58±10 years and paroxysmal AF was present in 93% of patients. Mean FU duration was 124±24 months. At the end of the observational period, 73% of all patients were in stable sinus rhythm after a mean of 2±0.8 ablation procedures. Patients with AF/AT recurrence were older (60±8vs.57±10 years; p=0.019), had a higher CHA₂ DS₂ -Vasc Score (2.47±1.46vs.1.98±1.50; p=0.01) and presented with a larger LA-diameter (43±5.6vs40±5.1 mm; p=0.002). The LA-diameter was also a significant predictor for AF/AT recurrence after CB-PVI (Odds Ratio: 0.939,95% CI [0.886, 0.992], p=0.03).
Conclusions
CB-PVI as index procedure for AF ablation resulted in favorable long-term outcome in symptomatic AF. CB-PVI might be recommended as interventional therapy in patients with lower LA remodeling. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 03 May 2022; epub ahead of print

Transient changes in QRS morphology during a narrow complex tachycardia: What is the mechanism?

Kara M, Cetin EHO, Korkmaz A, Ozeke O, ... Aras D, Topaloglu S
The observation of electrograms and electrocardiograms recorded in sinus rhythm can offer important initial information about the mechanism of arrhythmia. Some patients may have both bundle branch aberrancy or a bystander pathway or multiple pathways, giving rise to varying degrees of QRS fusion. There is need to focus on any change in cycle length of the tachycardia and morphology of QRS during tachycardia. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 06 May 2022; epub ahead of print

Anatomical variations in Coronary Venous Drainage: Challenges and Solutions in Delivering Cardiac Resynchronisation Therapy.

Akhtar Z, Sohal M, Kontogiannis C, Harding I, ... Beeton I, Gallagher MM
Aims
To investigate the abnormalities of the coronary venous system in candidates for cardiac resynchronization therapy (CRT) and describe methods for circumventing the resulting difficulties.
Methods
From 4 implanting institutes, data of all CRT implants between October 2008-October 2020 were screened for abnormal cardiac venous anatomy, defined as an anatomical variation not conforming to the accepted \'normal\' anatomy. Patient demographics, procedural detail and subsequent left ventricle (LV) lead pacing indices were collected.
Results
From a total of 3548 CRT implants, 15 (0.42%) patients (80% male) of 72.2±10.6 years in age with a LV ejection fraction of 34±10.3% were identified to have had an abnormal cardiac venous anatomy over the study period. There were 13 cases of persistent left side superior vena cava (pLSVC), 5 of which had coronary sinus ostium atresia (CSOA) including 2 with an \'unroofed\' coronary sinus (CS); 1 patient had a unique anomalous origin of the CS and 1 patient had an isolated CSOA. In total 14 patients (60% repeat attempt) had successful percutaneous implant under general anaesthesia (46.7%) via the cephalic vein (59.1%), using the femoral approach (53.3%) for levophase venography and/or pull-through, including 1 case of endocardial LV implant. Pacing follow-up over 37.64±37.6 months demonstrated LV lead threshold between 0.62-2.9 volts (pulsewidth 0.4-1.5 milliseconds) in all cases; 5 patients died within 2.92±1.6 years of successful implant.
Conclusion
CRT devices can be implanted percutaneously even in the presence of substantial abnormalities of coronary venous anatomy. Alternative routes of venous access may be required. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 06 May 2022; epub ahead of print

Predictors of Conduction Disturbances after Transcatheter Aortic Valve Implantation with Balloon-expandable Valve for Bicuspid Aortic Valve Stenosis.

Miyashita H, Moriyama N, Yamanaka F, Saito S, ... Niemelä M, Laine M
Objective
Implantation depth and membranous septum (MS) length have been established as the predictors of new-onset conduction disturbance (CD) after transcatheter aortic valve replacement (TAVR) for tricuspid aortic valve (TAV) stenosis. However, little is known about the predictors with bicuspid aortic valve (BAV). This study investigated the role of MS length and implantation depth in predicting CD following TAVR with a balloon-expandable valve in patients with BAV.
Methods and results
This retrospective study analyzed 169 patients who underwent TAVR for BAV with balloon-expandable valve, and TAV cohort was established as a control group using propensity score (PS) matching. The primary endpoints were in-hospital new permanent pacemaker implantation (PPI) new-onset CD (the composite outcome of new-onset left bundle branch block and new PPI). PPI developed in 14 patients (8.3%) and new-onset CD in 37 patients (21.9%) in BAV cohort. Multivariate analysis revealed severe LVOT calcification (Odds ratio [OR]: 5.83, 95% confidence interval [CI]: 1.08 - 31.5, p = 0.0407) and implantation depth - MS length (OR: 1.30, 95% CI: 1.12 - 1.51, p = 0.0005) as the predictors of new-onset CD within the BAV cohort. The matched comparison between BAV and TAV groups showed similar MS length (3.0 vs 3.2mm, p = 0.5307), but valves were implanted more deeply in the BAV group than in the TAV group (3.9 vs 3.0mm, p < .0001). New-onset CD was more frequent in patients who had BAV (22.3% vs 13.9%, p = 0.0458).
Conclusion
The implantation depth - MS length, and severe LVOT calcification predicted new-onset CD following TAVR in BAV with balloon-expandable valve. Among BAV patients, THV were implanted more deeply compared to THV patients. High deployment technique could be considered to avoid new-onset CD in BAV anatomy. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 11 May 2022; epub ahead of print

Dielectric-based Tissue Thickness Measured During Radiofrequency Catheter Ablation.

Schillaci V, Stabile G, Arestia A, Shopova G, ... De Simone A, Solimene F
A new dielectric-based method (KODEX-EPD mapping system, EPD Solutions, a Philips company) for measuring tissue thickness at the catheter-tissue interface has recently been developed. We reported preliminary data on real-time catheter-based measuring myocardial wall thickness in vivo, during typical atrial flutter radiofrequency ablation. The atrial wall thickness was significantly higher close to the tricuspid annulus than close to the inferior vena cava (3.6±0.5 mm vs 2.4±0.3 mm, p<0.001) and a trend towards a progressive decrease of atrial wall thickness was observed moving the mapping catheter from the tricuspid valve to the inferior vena cava. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 12 May 2022; epub ahead of print

Dielectric concept: \"A Magnification Lens in EP Lab?\"

Tondo C
It is well recognized that radiofrequency (RF) energy effect, is dependent upon several variables that impact lesion size and transmurality including catheter stability, contact force, power output, temperature, duration of RF output, and tissue characteristics and thickness This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 12 May 2022; epub ahead of print

DURABILITY OF LEFT BUNDLE BRANCH AREA PACING.

Mehta NA, Saqi B, Sabzwari SRA, Gupta R, ... Freudenberger R, Bozorgnia B
Background
Left bundle branch area pacing (LBBAP) is a form of conduction system pacing. Long term data on the safety and performance of LBBAP one year post device implantation has not been well described.
Methods and results
Sixty-five patients (49% females) who received LBBAP for bradycardia indications using the SelectSecure 3830 lead (Medtronic, Minneapolis, MN) were retrospectively evaluated. Clinical variables were examined. Lead parameters were obtained at implant and during regular follow-up. Mean age of patients was 75.7±10.1 years with left ventricular ejection fraction 59.8±10.4%. Indications for pacing were atrioventricular block 55%, sinus node dysfunction 19%, tachy-brady syndrome 15%, atrioventricular node ablation 8%, and bail out CRT 3%. Mean baseline QRS measured 120±38ms, paced QRS duration was 138±22ms. Paced QRS narrowed by 24ms in those with preexisting left bundle branch block (BBB), increased by 1ms in those with preexisting right BBB, and increased by 42ms in those with no BBB. LBBAP threshold at implant was 0.521±0.153V @0.4ms, and increased to 0.654±0.186V at 3 months (+26%), 0.707±0.186 V at 6 months (+36%), and 0.772±0.220V at 12 months (+48%). Patients with left BBB showed the maximum benefit with QRS narrowing 24ms. Pacing impedance remained unchanged with no procedure related complications.
Conclusion
LBBAP is a durable form of conduction system pacing with pacing thresholds remaining relatively stable over 12 months post device implantation. Patients with left BBB display the narrowest paced QRS. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 18 May 2022; epub ahead of print

Lowering the Threshold for Left Bundle Branch Area Pacing.

Cerbin LP, Garg L
Cardiac pacing remains the mainstay of therapy for conduction system disease and irreversible bradyarrhythmias. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 16 May 2022; epub ahead of print

Novel Computed Tomography Angiography-Based Sizing Methodology for WATCHMAN FLX Device in Left Atrial Appendage Closure.

Dallan LAP, Arruda M, Yoon SH, Rana MA, ... Rajagopalan S, Filby SJ
Background
While there is recent data suggesting an advantage of Computed Tomography Angiography (CTA) over transesophageal echocardiography (TEE) for pre-procedural left atrial appendage closure (LAAC) planning, there is limited published experience for sizing strategies. Device sizing for LAAC may be challenging and non-invasive algorithms that improve this selection process are warranted.
Objectives
We sought to evaluate the safety and the feasibility for the implementation of a novel CTA-based sizing methodology for WATCHMAN^™ FLX device in a series of patients undergoing LAAC using the TruPlan™ software package.
Methods
A prospective analysis of 136 consecutive patients who underwent LAAC over a 12-month period in a single, large academic hospital in the United States was conducted. CTA-guided pre-procedural planning and intracardiac echocardiography (ICE) was performed in all. Procedural success, adverse events, length of procedure, number of devices used, and length of stay were evaluated.
Results
A total of 136 patients who underwent LAAC procedure with WATCHMAN^™ FLX platform between October 1, 2020 until September 30, 2021 were included. The pre-specified protocol using CTA and ICE was implemented in all patients (100%). Mean CHA₂ DS₂ VASc score was 4.4 ± 1.3 and the mean HAS-BLED score was 3.9 ± 0.8. ICE-guided 100% transseptal puncture success rate was 100% with 98.5% of overall procedural success rate. Pre-procedural CTA sizing strategy accurately predicted the implanted size in 91.1% of patients. Ten patients (7.4%) required another sized device and 2 cases were aborted. At 45-day follow-up, only 1 patient (0.7%) had significant peri-device leak (≥ 5mm) on TEE.
Conclusions
CTA-based pre-procedural sizing methodology for WATCHMAN^™ FLX in LAAC was safe, feasible and associated with excellent procedural outcomes. Further studies are warranted to confirm if the features specific to TruPlan^™ may reduce the number of deployment attempts, the number of devices utilized in the procedure, and the risk of complications. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 18 May 2022; epub ahead of print

Contact Force Guided Radiofrequency Current Application at Developing Myocardium: Summary and Conclusions.

Backhoff D, Müller MJ, Betz T, Arnold A, ... Paul T, Krause U
Background
Catheter contact is one key determinant for lesion size in radiofrequency catheter ablation (RFA). Monitoring of contact force (CF) during RFA has been shown to improve efficacy of RFA in experimental settings as well as in adult patients. Coronary artery narrowing after RFA has been described in experimental settings as well as in children and adults and may be dependent from catheter contact. Value of CF monitoring concerning these issues has not been systematically yet.
Objective
Value of high versus low CF during RFA in piglets was studied to assess lesion size and potential coronary artery involvement mimicking RFA in small children.
Animals and methods
RFA with continuous CF monitoring was performed in 24 piglets (median weight 18.5 kg) using a 7F TactiCath Quartz RF ablation catheter (Abbott, Illinois, USA). A total of 7 lesions were induced in each animal applying low (10-20 g) or high (40-60 g) CF. RF energy was delivered with a target temperature of 65 °C at 30 W for 30 seconds. Coronary angiography was performed prior and immediately after RF application. Animals were assigned to repeat coronary angiography followed by heart removal after 48 h (n=12) or 6 months (n=12). Lesions with surrounding myocardium were excised, fixated and stained. Lesion volumes were measured by microscopic planimetry.
Results
A total of 148 RF lesions were identified in the explanted hearts. Only in the subset of lesions at the AV annulus 6 month after ablation, lesion size and number of lesions exhibiting transmural extension were higher in the high CF group compared to low CF. In all other locations CF had no impact on lesion size and mural extension after 48 h as well as after 6 months. Additional parameters as Lesion Size Index and Force Time Integral were also not related to lesion size. Coronary artery damage was present in 2 animals after 48 h and in 1 after 6 months and was not related to CF. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 16 May 2022; epub ahead of print

AMEN and ALARA - Remembering the dangers of the (new) technology of lesion formation.

Alexander ME, O\'leary ET
Catheter ablation in children has evolved to become a highly effective and safe therapy. Each iterative improvement in ablation technology provides another opportunity to investigate how much incremental benefit can be made without sacrificing safety. Contact force sensing catheters represent an example of such technology that has become commonplace in adult ablation. Its capability in predicting lesion size and collateral damage to critical structures has not been meticulously explored. Backhoff and colleagues describe an animal ablation model where they quantitate lesion characteristics at the atrium, atrioventricular groove, and ventricle using low and high contact force targets, with a specific focus on assessing for coronary arterial injury. In this controlled experiment, chronic lesion characteristics were widely variable (~0-8 mm diameter) yet there was a statistically significant (albeit small) increase in lesion diameter for high (vs low) contact force lesions delivered to the atrioventricular groove. The risk of chronic sub-clinical coronary artery injury was 1-2%. The remarkably weak association between contact force and lesion size suggests that delivery of clinical lesions needs to have both principles of As much as effectively needed (AMEN) and as low as reasonably achievable (ALARA), mirroring radiation exposure This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 16 May 2022; epub ahead of print

Patient-reported Outcomes and Costs Associated with Vascular Closure and Same-Day Discharge following Atrial Fibrillation Ablation.

Steinberg BA, Woolley S, Li H, Crawford C, ... Zhang Y, Jared Bunch T
Background
We aimed to measure patient reported outcomes (PROs) and costs associated with same day discharge (SDD) for AF ablation and vascular closure device implantation in clinical practice.
Methods
PROs were prospectively measured in 50 AF ablation patients, comparing complete vascular device closure (n=25) versus manual compression hemostasis (n=25). Health-system costs for SDD patients receiving vascular device closure were compared to matched controls with one-night stays who did not receive any closure device.
Results
Prospectively-enrolled patients receiving vascular device closure for AF ablation had mean age of 65 years, 17% were female, with a mean CHA₂ DS₂ -VASc score 3. Mean number of venous sheaths was higher among patients receiving vascular device closure (3.8 vs. 3.1,p<0.001), and there was 1 case of re-bleeding in a patient receiving vascular closure device (no other complications). Same-day discharge rates (76% vs. 8.3%,p<0.001), patient satisfaction with bedrest time (8.5 vs. 6,p=0.004) and with pain (8 vs. 5.1,p=0.009) were significantly better among patients receiving vascular closure. In matched analyses of health-system costs, patients with vascular closure had mean age 66, 32% were female, and mean CHA₂ DS₂ -VASc score was 2 (p=NS vs. controls). SDD with vascular closure was associated with significantly lower facility, pharmacy, and disposable costs, but higher implant costs. Overall costs for ablation were not significantly different (mean difference 1.10%, 95% CI -3.03-5.42).
Conclusions
Vascular closure for AF ablation improves patient experience in routine care. Use of vascular closure and SDD after AF ablation reduces several components of healthcare system costs, without an overall increase. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 May 2022; epub ahead of print

Durable pulmonary vein isolation with diffuse posterior left atrial ablation using low-flow, median power, short-duration strategy.

Li DL, El-Harasis M, Montgomery JA, Richardson TD, ... John RM, Michaud GF
Introduction
To target posterior wall isolation (PWI) in atrial fibrillation (AF) ablation, diffuse ablation theoretically confers a lower risk of conduction recovery compared to box set. We sought to assess the safety and efficacy of diffuse PWI with low-flow, medium-power, and short-duration (LF-MPSD) ablation, and evaluate the PVI and PWI durability among patients undergoing repeat ablations.
Methods
We retrospectively studied patients undergoing LF-MPSD ablation for AF (PVI + diffuse PWI) between 8/2017 and 12/2019. Clinical characteristics were collected. Kaplan-Meier survival analysis was performed to study AF/atrial flutter (AFL) recurrence. Ablation data were analyzed in patients who underwent a repeat AF/AFL ablation.
Results
Of the 463 patients undergoing LF-MPSD AF ablation (PVI alone, or PVI + diffuse PWI), 137 patients had PVI + diffuse PWI. Acute PWI with complete electrocardiogram elimination was achieved in 134 (97.8%) patients. Among the 126 patients with consistent follow up, 38 (30.2%) patients had AF/AFL recurrence during a median duration of 14 months. Eighteen patients underwent a repeat AF/AFL ablation after PVI + diffuse PWI, and 16 (88.9%) patients had durable PVI, in contrast to 10 of 45 (23.9%) patients who had redo ablation after LF-MPSD PVI alone. Seven patients (38.9%) had durable PWI, while 11 patients had partial electrical recovery at the posterior wall. The median percentage of area without electrical activity at the posterior wall was 70.7%. Conduction block across the posterior wall was maintained in 16 (88.9%) patients.
Conclusion
There was a high rate of PVI durability in patients undergoing diffuse PWI and PVI. Partial posterior wall electrical recovery was common but conduction block across the posterior wall was maintained in most patients. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 May 2022; epub ahead of print

Characteristics of Successful Reactive Atrial-based Antitachycardia Pacing in Patients with Cardiac Implantable Electronic Devices: History of Catheter Ablation of Atrial Fibrillation as a Predictor of High Treatment Efficacy.

Nakagomi T, Inden Y, Yanagisawa S, Suzuki N, ... Shibata R, Murohara T
Introduction
Reactive atrial-based antitachycardia pacing (rATP) in patients with cardiac implantable electronic devices (CIEDs) suppresses the progression of atrial fibrillation (AF) to the persistent form. However, the clinical factors associated with successful rATP treatment are unknown. This study aimed to examine the predictors of high rATP efficacy in patients with CIEDs.
Methods
The data of 101,325 rATP-treated atrial tachyarrhythmia (AT/AF) episodes in 51 patients, obtained through remote monitoring and device interrogation, were analyzed. The study population was divided into the high and low efficacy groups based on the overall median success rate of rATP. Clinical characteristics were compared between the two groups.
Results
During a follow-up period of 28.6±8.6 months, the median success rate was 43.7% (31.5-64.9%). The prevalence of a history of catheter ablation of AF was significantly higher in the high efficacy group than in the low efficacy group (73.0% vs. 44.0%, p=0.048) and was the only independent predictor of high rATP efficacy (odds ratio, 3.45; p=0.038). The rATP success rate in patients with (n=30) and without (n=21) a history of catheter ablation was 53.9% (40.0-67.5%) and 36.4% (22.2-47.7%), respectively (p=0.012). The effect of rATP after ablation was more pronounced in patients with long cycle length episodes (≥75% of AT/AF sequences having a cycle length of 200-449 ms) (67.3% [46.0-73.6%] vs. 30.6% [18.1-60.3%], p=0.027). The high efficacy group had a significantly lower incidence of AT/AF lasting ≥1, ≥7, and ≥30 days than the low efficacy group.
Conclusion
rATP combined with catheter ablation therapy is effective in suppressing AT/AF. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 May 2022; epub ahead of print

Left Atrial Posterior Wall Isolation - The Conundrum of Safety versus Efficacy.

Calvert P, Gupta D
The study by Worck et al. raises interesting findings with regard to left atrial posterior wall ablation. The utility of ablation at the CRZ - which may represent epicardial connection via the septopulmonary bundle - warrants future research. Upcoming trials utilising existing technology, along with increased availability of pulsed field ablation, will advance our knowledge of the impact of left atrial posterior wall isolation. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 May 2022; epub ahead of print

Posterior Wall Isolation in Persistent Atrial Fibrillation Feasibility, Safety, Durability and Efficacy.

Worck R, Sørensen SK, Johannessen A, Ruwald M, Haugdal M, Hansen J
Introduction
Posterior wall isolation (PWI) added to pulmonary vein isolation (PVI) is increasingly used despite limited evidence of clinical benefit. We investigated the feasibility, durability, and efficacy of index-procedure PVI + PWI radio frequency ablation (RFA) in patients with persistent atrial fibrillation (PeAF).
Methods and results
Twenty-four patients with PeAF participated in the prospective PeAF-Box study and underwent RFA with wide area circumferential ablation (WACA), roof- and inferior lines to achieve PVI + PWI at index procedure. Follow-up included monitoring by an implantable cardiac monitor (ICM), esophagoscopy and mandated invasive lesion-reassessment at six months. PWI was achieved at minor procedural cost in all patients following PVI. In 33% of patients a median of three ablations in the narrow zone between the center of the posterior wall (PW) and the posterior right carina was pivotal for swift achievement of PWI. At the 6-months reassessment procedure 85% (95% CI: 77-92%) of pulmonary veins (PV´s) and 46% (95% CI: 26-67%) of PW´s remained durably isolated. AF recurred in 25% and was associated with PV-reconnection (P = 0.02) but not PW-reconnection (P = 0.27). AF-burden was 0% (IQR: 0% to 0%) overall and after recurrence 1% (IQR: 0 % - 7 %)
Conclusion:
Index procedure PVI + PWI for PeAF was feasible when recognizing that limited ablation in a PW center-to-right-carina zone was required in a subset of patients. Despite limited chronic PWI durability this strategy was followed by low AF-burden. A PVI + PWI strategy appears promising in ablation for PeAF. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 May 2022; epub ahead of print

Seize the day, …s(e)ize the device: the emerging imaging modality to improve left atrial appendage device sizing.

Tondo C
There is still uncertainity about the use of CT-scan for LAAO device sizing. The main reason for this disappointing position is likely to relate to the scarcity of robust data, since there is still difference among institutions with regards how to perform measurement of the devices. Dallan et al. (1) report their own experience on the use of a novel computed tomography angiography-based (CTA) for sizing the Watchman Flex device for left atrial appendage occlusion (LAAO). The authors through the TruPlan software package that a pre-procedural CTA sizing protocol can be applied successfully with ICE guidance and provide excellent procedural outcomes.The applied CTA protocol is safe and can provide high success rates with the WatchmanTM FLX device reducing the number of deployment attempts and reducing the risk of complications. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 18 May 2022; epub ahead of print

The wall of unintended consequences: is the main benefit of posterior LA wall isolation simply more durable pulmonary vein isolation?

Zei PC
Medicine is rife with therapies originally developed for a specific purpose, yet after some time, the true benefit is determined to lie elsewhere - examples of the \"law of unintended consequences\". This article is protected by copyright. All rights reserved.

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J Cardiovasc Electrophysiol: 19 May 2022; epub ahead of print

Catheter Ablation for Atrial Fibrillation in the Elderly > 75 Years old: Systematic Review and Meta-Analysis.

Prasitlumkum N, Tokavanich N, Trongtorsak A, Cheungpasitporn W, ... Jared Bunch T, Navaravong L
Introduction
Atrial fibrillation (AF) ablation is increasingly performed worldwide. As comfort with AF ablation increases, the procedure is increasingly used in patients that are older and in those with more comorbidities. However, it is not well established whether AF ablation in the elderly, especially those >75 years old, has comparable safety and efficacy to younger populations.
Objective
To compare the efficacy and safety profiles in patients older than 75years undergoing AF ablation with younger patients.
Methods
Databases from EMBASE, Medline, PubMed and Cochrane, were searched from inception through September 2021. Studies that compared the success rates in AF catheter ablation and all complications rates between patients who were older vs under 75 years were included. Effect estimates from the individual studies were extracted and combined using random effect, generic inverse variance method of DerSimonian and Laird.
Results
Twenty-seven observational studies were included in the analysis consisting of 363,542 patients who underwent AF ablation. Comparing patients older than 75 years old to younger patients, there was no difference in the success of ablation rates between elderly and younger patients (pooled OR 0.85: 95% CI:0.69 - 1.05, p=0.131). On the other hand, AF ablation in the elderly was associated with higher complication rates (pooled OR 1.43: 95% CI:1.21 - 1.68, p<0.001)
Conclusion:
As AF ablation is expanded to elderly populations, our study found that AF ablation success rates were similar in both elderly and younger patients. However, older patients experience higher rates of complications that should be considered when offering the procedure and as a means to improve outcomes with future innovations. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 19 May 2022; epub ahead of print

Can All Stakeholders Benefit from Same Day Discharge Following Catheter Ablation of Atrial Fibrillation?

Musat D, Mittal S
Same-day discharge after AF ablation procedure is becoming the preferred trend. Vascular closure devices use have shortened the post-procedural bedrest, associated with increased patient satisfaction. Although this approach comes with a cost, it might also beneficial to the healthcare system. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 May 2022; epub ahead of print

Initial experience of left bundle branch area pacing using stylet-driven pacing leads: a multicenter study.

De Pooter J, Ozpak E, Calle S, Peytchev P, ... Wauters A, le Polain de Waroux JB
Background
Left bundle branch area pacing (LBBAP) has been performed exclusively using lumen-less pacing leads (LLL) with fixed helix design. This registry study explores the safety and feasibility of LBBAP using stylet-driven leads (SDL) with extendable helix design in a multicenter patient population.
Methods
This study prospectively enrolled consecutive patients who underwent LBBAP for bradycardia pacing or heart failure indications at eight Belgian hospitals. LBBAP was attempted using SDL (Solia S60, Biotronik) delivered through dedicated delivery sheath (Selectra3D). Implant success, complications, procedural and pacing characteristics were recorded at implant and follow-up.
Results
The study enrolled 353 patients (mean age 76±39 years, 43% female). The mean number of implants per center was 25 (range 5-162). Overall, LBBAP with SDL was successful in 334/353 (94%), varying from 93 to 100% among centers. Pacing response was labeled as left bundle branch pacing in 73%, whereas 27% were labeled as myocardial capture. Mean paced QRS duration and stimulus to left ventricular activation time measured 126±21ms and 74±17. SDL LBBAP resulted in low pacing thresholds (0.6±0.4V at 0.4ms), which remained stable at 12 months follow-up (0.7±0.3, p=0.291). Lead revisions for SDL LBBAP occurred in 5(1.4%) patients occurred during a mean follow up of 9±5 months. Five (1.4%) septal coronary artery fistulas and 8(2%) septal perforations occurred, none of them causing persistent ventricular septal defects.
Conclusion
The use of SDL to achieve LBBAP is safe and feasible, characterized by high implant success in low and high volume centers, low complication rates, and stable low pacing thresholds. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 22 May 2022; epub ahead of print

Short-Term Natural Course of Esophageal Thermal Injury After Ablation for Atrial Fibrillation.

Ishidoya Y, Kwan E, Dosdall DJ, Macleod RS, ... Jared Bunch T, Ranjan R
Purpose
To provide insight into the short-term natural history of esophageal thermal injury (ETI) after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) by esophagogastroduodenoscopy (EGD).
Methods
We screened patients who underwent RFCA for AF and EGD based on esophageal late gadolinium enhancement (LGE) in post ablation MRI. Patients with ETI diagnosed with EGD were included. We defined severity of ETI according to Kansas City classification (KCC): type 1: erythema; type 2: ulcers (2a: superficial; 2b deep); type 3 perforation (3a: perforation; 3b: perforation with atrioesophageal fistula). Repeated EGD was performed within 1-14 days after the last EGD if recommended and possible until any certain healing signs (visible reduction in size without deepening of ETI or complete resolution) were observed.
Results
ETI was observed in 62 of 378 patients who underwent EGD after RFCA. Out of these 62 patients with ETI, 21% (13) were type 1, 50% (31) were type 2a and 29% (18) were type 2b at the initial EGD. All esophageal lesions, but one type 2b lesion that developed into an atrioesophageal fistula (AEF), showed signs of healing in repeated EGD studies within 14 days after the procedure. The one type 2b lesion developing into an AEF showed an increase in size and ulcer deepening in repeat EGD 8 days after the procedure.
Conclusion
We found that all ETI which didn\'t progress to AEF presented healing signs within 14 days after the procedure and that worsening ETI might be an early signal for developing esophageal perforation. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 23 May 2022; epub ahead of print

Stand-alone Focal Impulse and Rotor Modulation (FIRM) ablation versus second-generation cryoballoon pulmonary vein isolation for paroxysmal atrial fibrillation.

Tilz RR, Yalin K, Lyan E, Heeger CH, ... Eitel C, Vogler J
Introduction
Focal Impulse and Rotor Modulation (FIRM) guided catheter ablation aiming at stable rotors has been investigated as a treatment option in patients with atrial fibrillation (AF). The objective of this study was to compare the safety and efficacy of FIRM-guided ablation with second-generation cryoballoon pulmonary vein isolation (CB2-PVI) in paroxysmal AF.
Methods
Consecutive patients (n=22, mean age 60 ± 11 years, 59.1% of males) who were treated with a stand-alone FIRM-guided ablation were included in this retrospective single-center study. Procedural data and arrhythmia-free survival at 12 months were compared with n=86 consecutive patients (mean age 62 ± 13 years, 62.4% of males) who received de-novo CB2-PVI.
Results
Median procedure duration was significantly longer in the FIRM group than in the CB2-PVI group (152 [IQR 120;176] minutes versus 122 [110;145] minutes; p=0.031). One patient (1.2%) in the CB2-PVI group and 5 patients (22.7%) in the FIRM group had vascular access complications. Atrial tachyarrhythmias recurred in 15 patients in the FIRM group and 11 in the CB2-PVI group. Kaplan-Meier estimation of single-procedure arrhythmia-free survival at 12 months was 25% (95% CI 6-44%) in the FIRM group and 87% (95% CI 78-96%) in the CB2-PVI group (p<0.001). Repeat ablations were performed in 14/20 (70.0%) patients in the FIRM group and in 12/85 (14.1%) in the CB2-PVI group (p<0.001).
Conclusion
De novo ablation of AF using FIRM-guided AF ablation results in shorter arrhythmia-free survival after 12 months compared to CB2-PVI and a need for repeat ablation in the majority of patients to achieve stable sinus rhythm. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 26 May 2022; epub ahead of print

Simultaneous narrow and wide QRS complex tachycardia: Misdiagnosis or Missed diagnosis?

Aslan AO, Merovci I, Tunçez A, Oksuz F, ... Aras D, Topaloglu S
Tachycardia-induced tachycardia, or so-called double tachycardia, appears to be a relatively rare condition. Regardless of the mechanism, this case illustrates the importance of assessing the response to multiple different pacing maneuvers in determining the mechanism of narrow and wide QRS complex tachycardias, rather than relying upon a single maneuver, even one that is believed to be diagnostic. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 25 May 2022; epub ahead of print

Case report: Epicardial Ligation of the Left Atrial Appendage in a Patient with an inaccessible left atrial cavity.

Nentwich K, Ene E, Müller J, Berkowitz A, Kerber S, Deneke T
It has been shown that endocardial occlusion of the left atrial appendage (LAA) is equally effective in preventing embolic events compared to oral anticoagulation in patients with non-valvular atrial fibrillation An 82-year old female patient was admitted for LAA occlusion for repetitive GI bleeding. She had high CHADSVASC Score and HASBLED with long persistent atrial fibrillation with many comorbities. The preprocedural transesophageal echo revealed a great mass in the left atrium. (picture 1). Cardiac surgery was denied, we performed an epicardial only ligation for closing the LAA. For this approach we performed an epicardial puncture and contrast injection within the pericardial space to delineate the LAA. An epicardial wire with a suction mechanism at its distal end was attached to the anterior lobe of the left atrial appendage. Using this epicardial wire the snare could be advanced over the appendage and closed down. Complete exclusion of the LAA was achieved. There were no procedural complications and the patient is doing well after 3 month. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 25 May 2022; epub ahead of print

Evolution of tricuspid valve regurgitation after implantation of a leadless pacemaker - a single center experience, systematic review and meta-analysis.

Haeberlin A, Bartkowiak J, Brugger N, Tanner H, ... Noti F, Reichlin T
Introduction
Conventional transvenous pacemaker leads may interfere with the tricuspid valve leaflets, tendinous chords and papillary muscles, resulting in significant tricuspid valve regurgitation (TR). Leadless pacemakers (LLPMs) theoretically cause less mechanical interference with the tricuspid valve apparatus. However, data on TR after LLPM implantation are sparse and conflicting. Our goal was to investigate the prevalence of significant TR before and after LLPM implantation.
Methods
Patients who received a leadless LLPM (Micra™ TPS, Medtronic, US) between 05/2016 and 05/2021 at our center were included in this observational study if they had at least a pre- and postinterventional echocardiogram (TTE). The evolution of TR severity was assessed. Following a systematic literature review on TR evolution after implantation of a LLPM, data were pooled in a random-effects meta-analysis.
Results
We included 69 patients (median age 78 years [interquartile range (IQR) 72-84 years], 26% women). Follow-up duration between baseline and follow-up TTE was 11.4 months (IQR 3.5-20.1 months). At follow-up, overall TR severity was not different compared to baseline (p=0.49). Six patients (9%) had new significant TR during follow-up after LLPM implantation, whereas TR severity improved in seven patients (10%). In the systematic review, we identified seven additional articles that investigated the prevalence of significant TR after LLPM implantation. The meta-analysis based on 297 patients failed to show a difference in significant TR before and after LLPM implantation (risk ratio 1.22, 95%-CI 0.97-1.53, p=0.11).
Conclusion
To date, there is no substantial evidence for a significant change in TR after implantation of a LLPM. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 25 May 2022; epub ahead of print

The Coronary Sinus Marshall Structure: from an Anatomical Ligament to an Arrhythmogenic Vein.

Rostock T, Spittler R
The original Marshall Plan was a foreign aid program of the United States to prevent the economic deterioration of Western European countries after the second world war, with a particular focus on Western Germany. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

Assessment of the Need of a Waiting Period after Pulmonary Vein Isolation with the Ablation Index Software.

Sousa PA, Barra S, Adão L, Primo J, ... Gonçalves L, other members of the Study Group
Purpose
Since the widespread availability of contact-force sensing catheters, the need of a waiting period after pulmonary vein isolation (PVI) has not been reassessed. We aim to evaluate whether a waiting period is still necessary after PVI guided by the Ablation Index (AI).
Methods
Prospective, multicenter, randomized study of consecutive patients referred for paroxysmal atrial fibrillation (AF) ablation from May 2019 to February 2020. Patients were randomized in a 1:1 ratio to PVI with versus without a waiting period of 20 minutes. Acute pulmonary vein (PV) reconnection after adenosine challenge was the primary endpoint. A per-protocol analysis was designed to determine whether a strategy of dismissing the waiting period after PVI was noninferior to waiting 20minutes for identifying acute PV reconnection. PVI was guided by tailored AI values and an inter-lesion distance ≤6mm.
Results
During the enrollment period, 167 patients (56% males, mean age of 57±14 years) fulfilled the study inclusion criteria - 84 patients (308 PV) in the waiting period group (group A) and 83 patients (314 PV) in the group without a waiting period (group B). Acute PV reconnection was identified in 3.8% (95% CI, 1.7% to 5.9%) of PVs in the study group B compared to 2.9% (95% CI, 1.0% to 4.8%) of PVs in the group A (p=0.002 for non-inferiority). At 1-year follow-up there was no significant difference in arrhythmia recurrence between groups (9.5% in group A vs. 9.6% in group B, HR 1.03 [95% CI, 0.39-2.73], p=0.98).
Conclusions
In paroxysmal AF patients submitted to ablation, a tailored PVI guided by the Ablation Index rendered a 20-minute waiting period unnecessary. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

Time to say good bye? - the value of waiting period after pulmonary vein isolation.

Knecht S, Badertscher P
The study by Sousa et al. challenged the need of a waiting period of 20 min after radiofrequency pulmonary vein isolation (PVI) guided by Ablation index (AI). With their randomized controlled trial, they showed that in patients with paroxysmal atrial fibrillation, a waiting period was unnecessary for their tailored PVI guided by the AI. This can be explained by the continuous advances in RF technology, resulting in improved efficacy and effectiveness of PVI. However, the relevance of the performed adenosine testing is still not answered. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

A Comparison of Clinical Outcomes and Cost of Radiofrequency Catheter Ablation for Atrial Fibrillation with Monitored Anesthesia Care vs General Anesthesia.

Yokokawa M, Chugh A, Dubovoy A, Engoren M, ... Morady F, Oral H
Background
Monitored anesthesia care (MAC) or general anesthesia (GA) can be used during catheter ablation (CA) of atrial fibrillation (AF). However, each approach may have advantages and disadvantages with variability in operator preferences. The optimal approach has not been well established.
Objective
To compare procedural efficacy, safety, clinical outcomes, and cost of CA for AF performed with MAC vs GA.
Methods and results
The study population consisted of 810 consecutive patients (mean age: 63±10 years, paroxysmal AF: 48%) who underwent a first CA for AF. All patients completed a pre-procedural evaluation by the anesthesiologists. Among the 810 patients, MAC was used in 534 (66%) and GA in 276 (34%). Ten patients (1.5%) had to convert to GA during the CA. Although the total anesthesia care was longer with GA particularly in patients with persistent AF, CA was shorter by 5 min with GA than MAC (P<0.01). Prevalence of perioperative complications was similar between the 2 groups (4% vs 4%, P=0.89). There was no atrio-esophageal fistula with either approach. GA was associated with a small, ~7% increase in total charges due to longer anesthesia care. During 43±17 months of follow-up after a single ablation procedure, 271/534 patients (51%) in the MAC and 129/276 (47%) patients in the GA groups were in sinus rhythm without concomitant antiarrhythmic drug therapy (P=0.28).
Conclusion
With the participation of an anesthesiologist, and proper preoperative assessment, CA of AF using GA or MAC has similar efficacy and safety. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 02 Jun 2022; epub ahead of print

Distribution of Atrial Low Voltage Induced by Vein of Marshall Ethanol Infusion.

Kamakura T, André C, Duchateau J, Nakashima T, ... Derval N, Pambrun T
Introduction
Systematic and quantitative descriptions of vein of Marshall (VOM)-induced tissue ablation are lacking. We sought to characterize the distribution of low voltage observed in the left atrium (LA) after VOM ethanol infusion.
Methods and results
The distribution of ethanol-induced low voltage was evaluated by comparing high-density maps performed before and after VOM ethanol infusion in 114 patients referred for atrial fibrillation ablation. The two most frequently impacted segments were the inferior portion of the ridge (82.5%) and the first half of the mitral isthmus (pulmonary vein side) (92.1%). Low-voltage absence in these typical areas resulted from inadvertent ethanol infusion in the left atrial appendage vein (n=3), initial VOM dissection (n=3), or a \"no branches\" VOM morphology (n=1). Visible anastomosis of the VOM with roof or posterior veins more frequently resulted in low-voltage extension beyond typical areas, toward the entire left antrum (19.0% vs 1.9%, p = 0.0045) or the posterior LA (39.7% vs 3.8%, p < 0.001) but with a limited positive predictive value ranging from 29.4% to 43.5%. Ethanol-induced low voltage covered a median LA surface of 3.6% [1.9%-5.0%] and did not exceed 8% of the LA surface in 90% of patients.
Conclusion
VOM ethanol infusion typically locates at the inferior ridge and the adjacent half of the mitral isthmus. Low-voltage extensions can be anticipated but not guaranteed by the presence of visible anastomosis of the VOM with roof or posterior veins. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

Thoracoscopic Management of Iatrogenic Cardiac Perforations.

Langenaeken T, Van den Berg M, Kaya A, Yilmaz A
Aims
Iatrogenic cardiac perforation is an uncommon but potentially fatal complication of invasive cardiac procedures. When non-surgical management fails, urgent cardiac surgery is required. Standard surgical approach is usually through full sternotomy. However, we propose a less invasive and equally effective technique with video-assisted thoracoscopic surgery (VATS).
Methods
This single-centre retrospective study in a tertiary hospital identified all patients requiring surgical intervention due to iatrogenic cardiac perforation over a period of 5 years. Patients were grouped by surgical approach, being either sternotomy or VATS. Primary endpoints were operating time, length of ICU stay, hospital stay, 30-day mortality and all round mortality.
Results
25 patients were identified: 11 in the sternotomy-group and 14 in the VATS-group. Preoperative baseline characteristics were equal. Significant difference was found for 30-day mortality (p < 0.05). There was no difference for the other endpoints.
Conclusions
Video-assisted thoracoscopic surgery is a promising alternative to standard sternotomy for iatrogenic cardiac perforations after invasive cardiac procedures. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 31 May 2022; epub ahead of print

Bipolar Catheter Ablation Strategies for Outflow Tract Ventricular Arrhythmias Refractory to Unipolar Ablation.

Zhou B, Yu J, Ju W, Li X, ... Yang B, Chen M
Introduction
Conventional unipolar catheter ablation (UA) is generally effective for the treatment of outflow tract ventricular arrhythmias (OT-VAs). However, deep foci refractory to UA remains a clinical challenge. The present study evaluated the efficacy and safety of bipolar ablation (BA) in the treatment of OT-VAs refractory to UA.
Methods
A total of 1022 consecutive patients with anti-arrhythmic drugs resistant OT-VAs were screened for inclusion in this study, from 1643 VAs cases who underwent catheter ablation in two centers from October 2014 to May 2019. BA was performed after failed sequential UA. The pair of catheters used for BA was positioned on opposing surfaces of the earliest activation (EA) sites or on adjacent anatomical structures.
Results
Twelve patients (7 males, mean age 33.3 ± 16.2 years) who met the inclusion criteria were recruited: one patient suffered sustained monomorphic ventricular tachycardia (VT), six patients had frequent premature ventricular contractions (PVCs) and non-sustained VT (NSVT), and 5 patients had PVCs only. The 24-hr PVC/NSVT burden was 36.9 ± 21.7%. The mean distance between two ablation catheters during BA was 11.1 ± 4.3 mm (range 6.5-23.9 mm). The \"rS\" morphology of the unipolar electrogram was recorded simultaneously in both EA regions in seven cases (58.3%). Acute eradication of VAs was obtained in 10 (83.3%) cases. At a median follow-up of 58 months, 10 patients (83.3%) remained free from VAs.
Conclusion
BA was highly effective and safe for the treatment of OT-VAs refractory to UA. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

Change in atrial activation pattern during ventricular pacing - What is the mechanism?

Mukherjee SS, Bera D, Kumar D, Majumder S
A 46-year-old lady presented to out-patient department with recurrent episodic palpitations having preexcitation on ECG. She was advised electrophysiology study (EPS) and radiofrequency ablation (RFA) This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

Entrainment of ventricular tachycardia with V-shaped diastolic activation pattern: Is the pacing site in or out?

Tuncez A, Aslan AO, Merovci I, Oksuz F, ... Aras D, Topaloglu S
The use and interpretation of entrainment mapping, or continuous resetting, of a reentrant ventricular tachycardia, has been regarded as the gold standard for delineation of the components of a reentrant circuit. However, there are both inherent limitations and interpretative pitfalls to entrainment mapping. Beyond the far-field (FF) signals, the multiple near-field (NF) components may also be recorded at a given site and pacing typically interacts and captures only one component of the local activation. In the evaluation of the entrainment response, it is crucial to distinguish the NF electrogram captured from FF or other NF components to accurately measure the post-pacing interval, particularly in the presence of multiple NF signals This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

Long-term follow-up of patients with a quadripolar active fixation left ventricular lead. An Italian multicenter experience.

De Regibus V, Biffi M, Infusino T, Savastano S, ... Urraro F, Ziacchi M
Introduction
Left ventricular (LV) lead optimal positioning is one of the most important determinant of cardiac resynchronization therapy (CRT) success. LV quadripolar active fixation (QAF) leads have been designed to ensure stable LV pacing in the target area and reduce the likelihood of phrenic nerve stimulation (PNS). The aim of this analysis is to compare performances, safety and clinical outcomes of QAF with those of quadripolar passive fixation (QPL) and bipolar active fixation (BAF) leads in a real-world cohort of CRT patients.
Methods and results
This retrospective analysis compared procedure and follow-up data of 117 QAF included in the One Hospital ClinicalService project from 9 Italian hospitals with two historical cohorts of 261 BAF and 124 QPL. QAF enabled basal pacing more frequently than QPL (24.1% vs. 6.5%, p<0.001) but not differently from BAF (p=0.981). At implant, mean QAF LV myocardial threshold (LVMT) was 1.21±0.8V at 0.4 ms, not different from that of BAF (p=0.346) and QPL (p=0.333). At a median follow-up of 22 months, LVMT was 1.37±0.90 V (p=0.036 vs. implant). Acute LV lead dislodgment occurrence was low in all cohorts: 1 (0.9%) in QAF, 4 in BAF (1.5%) and none (0.0%) in QPL. During follow-up, total LV-related complication rate was lower in QAF (0.5/100 patient-years) than in BAF (4.2/100 patient-years, p=0.014) and QPL (3.6/100 patient/years, p=0.055). QAF, BAF and QPL annual rate of heart failure hospitalization were respectively 6.1/100 patient-years, 2.5/100 patient-years (p=0.081) and 3.6/100 patient-years (p=0.346). CRT responders\' rate in QAF was 69.9%, with no difference in comparison to BAF (p=0.998) and QPL (p=0.509). During follow-up, mean LVEF of QAF increased from 31.8 ± 10.1% to 40.3 ± 10.7% (p<0.001). The average degree of echocardiographic response (ΔLVEF) did not differ between QAF and other cohorts; however, LVEF CRT responder\'s distribution of QAF differs from those of BAF (p=0.003) and QPL (p=0.022), due to a higher percentage of super-responders.
Conclusions
QAF with short inter-electrode spacing resulted in noninferior clinical outcome and CRT responders\' rate in comparison to BAF and QPL, while reducing complication rate during follow-up and increasing the possibilities of electronic repositioning to manage PNS or to optimize resynchronization therapy. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

Implementation of supervised physical training to reduce vasovagal syncope recurrence: a randomized controlled trial.

Aghajani F, Tavolinejad H, Sadeghian S, Bozorgi A, ... Poopak A, Tajdini M
Background
Physical techniques used for prevention of vasovagal syncope have limited evidence for efficacy. We aimed to evaluate multimodal supervised physical training as a treatment approach.
Methods
In this 1:1 randomized trial patients with ≥2 episodes of clinically diagnosed vasovagal syncope were included. On top of standard care, the intervention arm performed supervised tilt training and aerobic exercise in six sessions at a cardiac rehabilitation center (three sessions during the first month, and then at three-month intervals), plus home tilt training. The control arm received standard care with a similar protocol of home tilt training. The primary outcome was time to first syncopal recurrence during one year of follow-up.
Results
Fifty participants were randomized (mean age: 34.5±14.8 years; 64% female). The rate of syncopal recurrence was 28% and 64% within the intervention and control arms, respectively, with significantly higher syncope-free survival at one year in the intervention arm (Log-rank P=0.003). The frequency of recurrent syncopal events was significantly lower with physical training (P=0.017). Participants in the intervention arm reported a significantly higher adherence to home tilt training program (80% versus 52%; P=0.037).
Conclusion
Among patients with recurrent vasovagal syncope, a supervised program of tilt training and aerobic exercise reduced syncopal recurrence. Future trials are warranted to further investigate multimodal supervised physical techniques as a therapeutic approach in treating vasovagal syncope. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

Bipolar Ablation for Outflow Tract Ventricular Arrhythmias: When the Going gets Tough, Two Catheters may be Better than One.

Huntrakul A, Liang JJ
Radiofrequency catheter ablation (RFCA) is an effective treatment strategy for patients with symptomatic ventricular arrhythmias (VAs) This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

Treating Syncope Without Drugs: Standing Still, Exercising Hard, or Simply the \"Expert\'s Touch\"?

Sheldon RS, Raj SR
Vasovagal syncope has been with humanity for countless millennia but has only been a target of active clinical research since the first seminal reports on tilt testing This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 30 May 2022; epub ahead of print

Left Atrial Appendage Emptying Velocity As a Predictor of Recurrence of Post-Ablation Atrial Fibrillation.

Ezzeddine FM, DeSimone CV
One of the major problems facing both patients and electrophysiologists in catheter ablation (CA) of atrial fibrillation (AF) is the limited objective data to determine abnormal atrial substrate pre-procedurally. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 02 Jun 2022; epub ahead of print

Holding Still for AF Ablation.

Sanders DJ, Wasserlauf J
Appropriate procedural sedation is imperative to successful catheter ablation (CA) for atrial fibrillation (AF). This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 02 Jun 2022; epub ahead of print

Low Left Atrial Appendage Emptying Velocity is a Predictor of Atrial Fibrillation Recurrence After Catheter Ablation.

Thotamgari SR, Sheth AR, Ahmad J, Bawa D, ... Amorn A, Dominic P
Background
Recurrence of atrial fibrillation (AF) after catheter ablation (CA) remains common and studies have shown about 5%-9% annual recurrence rate after CA. We sought to assess the echocardiogram derived left atrial appendage (LAA) emptying velocity as a predictor of AF recurrence after CA.
Objective
To determine if LAA emptying is a marker of recurrence of AF post-CA
Methods:
A total of 303 consecutive patients who underwent CA for AF between 2014 and 2020 were included. Baseline clinical characteristics and echocardiographic data of the patients were obtained by chart review. LAA emptying velocities were obtained from TEE. LA voltage was obtained during the mapping for CA. Chi-square test and nominal logistic regression were used for statistical analysis. An ROC curve was used to determine LAA velocity cut-off.
Results
Mean patient age was 61.7±10.5; 32% were female. Mean LAA emptying velocity was 47.5±20.2. A total of 103 (40%) patients had recurrence after CA. In the multivariable model, after adjusting for potential confounders, LAA emptying velocity of ≥52.3 was associated with decreased AF recurrence post-ablation (OR 0.55; 95% CI: 0.31-0.97; p = 0.03*). There were 190 (73%) patients in normal sinus rhythm during TEE and CA, and sensitivity analysis of these patients showed that LAA velocity ≥52.3 remained associated with decreased AF recurrence (OR 0.35; 95% CI 0.15-0.82; p = 0.01*).
Conclusion
LAA emptying velocity measured during pre-procedural TEE can serve as a predictor of AF recurrence in patients undergoing CA. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 02 Jun 2022; epub ahead of print

Shorter Distance Between The Esophagus And The Left Atrium Is Associated With Higher Rates Of Esophageal Thermal Injury After Radiofrequency Ablation.

Ishidoya Y, Kwan E, Dosdall DJ, Macleod RS, ... Jared Bunch T, Ranjan R
Background
Esophageal thermal injury (ETI) is a known and potentially serious complication of catheter ablation for atrial fibrillation. We intended to evaluate the distance between the esophagus and the left atrium posterior wall (LAPW) and its association with esophageal thermal injury.
Methods
A retrospective analysis of 73 patients who underwent esophagogastroduodenoscopy (EGD) after LA radiofrequency catheter ablation for symptomatic atrial fibrillation and pre-ablation magnetic resonance imaging (MRI) was used to identify the minimum distance between the inner lumen of the esophagus and the ablated atrial endocardium (pre-ablation atrial esophageal distance; pre-AED) and occurrence of ETI. Parameters of ablation index (AI, Visitag Surpoint) were collected in 30 patients from the CARTO3 system and compared to assess if ablation strategies and AI further impacted risk of ETI.
Results
Pre-AED was significantly larger in patients without ETI than those with ETI (5.23 ± 0.96 mm vs 4.31 ± 0.75 mm, p < 0.001). Pre-AED showed high accuracy for predicting ETI with the best cutoff value of 4.37 mm. AI was statistically comparable between Visitag lesion markers with and without associated esophageal late gadolinium enhancement (LGE) detected by post-ablation MRI in the low-power long-duration ablation group (LPLD, 25-40W for 10 to 30 s, 393.16 [308.62, 408.86] versus 406.58 [364.38, 451.22], p = 0.16) and high-power short-duration group (HPSD, 50W for 5-10 s, 336.14 [299.66, 380.11] versus 330.54 [286.21, 384.71], p = 0.53), respectively.
Conclusion
Measuring the distance between the LA and the esophagus in pre-ablation LGE-MRI could be helpful in predicting ETI after LAPW ablation. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 28 May 2022; epub ahead of print

How to use pace mapping for ventricular tachycardia ablation in post-infarct patients.

Guenancia C, Supple G, Sellal JM, Magnin-Poull I, ... Marchlinski F, de Chillou C
We aim to describe the technical aspects of pace mapping (PM), as well as the two typical patterns of pacing correlation maps during ventricular tachycardia (VT) ablation. The first main pattern is focal, with a gradual and eccentric decrease of the QRS correlation from the area with the best PM correlation. This focal pattern may be associated with two clinical situations: With some endocardial points showing a good correlation compared to VT morphology : true endocardial exit of VT or endocardial breakthrough of either an intramural or an epicardial circuit Without any endocardial points showing a good correlation compared to VT morphology: the VT may originate from the other ventricle, but the presence of an intramural or an epicardial circuit should be considered in patients with a structural heart disease. The second pattern is the presence of PM points exhibiting a good correlation close to other PM points showing a poor correlation compared to VT morphology: this abrupt change in paced QRS morphology over a short distance indicates a divergence of activation wavefronts between these sites and suggests the presence of a slow conduction channel: the VT isthmus. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 06 Jun 2022; epub ahead of print

High Density Pace-Mapping for Scar-related Ventricular Tachycardia Ablation.

Richardson TD, Stevenson WG
Despite advances in medical and interventional therapies, ventricular tachycardia (VT) due to reentrant activity within complex regions of myocardial scar remains a common late complication of myocardial infarction This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

J Cardiovasc Electrophysiol: 06 Jun 2022; epub ahead of print