Journal: Circ Arrhythm Electrophysiol

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Abstract

Catheter Ablation Versus Best Medical Therapy in Patients With Persistent Atrial Fibrillation and Congestive Heart Failure: The Randomized AMICA Trial.

Kuck KH, Merkely B, Zahn R, Arentz T, ... Kleemann T, Hindricks G
Background
Optimal treatment of patients with persistent atrial fibrillation (AF) and heart failure (HF) with reduced left ventricular ejection fraction (LVEF) and an indication for internal defibrillator therapy is controversial.
Methods
Patients with persistent/longstanding persistent AF and LVEF ≤35% were randomly allocated to catheter ablation of AF or best medical therapy (BMT). The primary study end point was the absolute increase in LVEF from baseline at 1 year. Secondary end points included 6-minute walk test, quality-of-life, and NT-proBNP (N-terminal pro-brain natriuretic peptide). Pulmonary vein isolation was the primary ablation approach; BMT comprised rate or rhythm control. All patients were discharged after index hospitalization with a cardioverter-defibrillator or cardiac resynchronization therapy defibrillator implanted. The study was terminated early for futility.
Results
Of 140 patients (65±8 years, 126 [90%] men) available for the end point analysis, 68 and 72 patients were assigned to ablation and BMT, respectively. At 1 year, LVEF had increased in ablation patients by 8.8% (95% CI, 5.8%-11.9%) and in BMT patients by 7.3% (4.3%-10.3%; =0.36). Sinus rhythm was recorded on 12-lead electrocardiograms at 1 year in 61/83 ablation patients (73.5%) and 42/84 BMT patients (50%). Device-recorded AF burden at 1 year was 0% or maximally 5% of the time in 28/39 ablation patients (72%) and 16/36 BMT patients (44%). There was no difference in secondary end point outcome between ablation patients and BMT patients.
Conclusions
The AMICA trial (Atrial Fibrillation Management in Congestive Heart Failure With Ablation) did not reveal any benefit of catheter ablation in patients with AF and advanced HF. This was mainly because of the fact that at 1 year, LVEF increased in ablation patients to a similar extent as in BMT patients. The effect of catheter ablation of AF in patients with HF may be affected by the extent of HF at baseline, with a rather limited ablation benefit in patients with seriously advanced HF.
Clinical trial registration
URL: https://www.clinicaltrials.gov. Unique identifier: NCT00652522.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007731
Kuck KH, Merkely B, Zahn R, Arentz T, ... Kleemann T, Hindricks G
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007731 | PMID: 31760819
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Abstract

Does Ventricular Tachycardia Ablation Targeting Local Abnormal Ventricular Activity Elimination Reduce Ventricular Fibrillation Incidence?

Kitamura T, Maury P, Lam A, Sacher F, ... Haissaguerre M, Jais P
Background
Various strategies for ablation of ventricular tachycardia (VT) have been described, but their impact on ventricular fibrillation (VF) is largely unknown. The aim of our study was to assess the effect of substrate-based VT ablation targeting local abnormal ventricular activity (LAVA) on recurrent VF events in patients with structural heart disease.
Methods
A retrospective 2-center study was performed on patients with structural heart disease and both VT and VF, with incident VT ablation procedures targeting LAVAs. Generalized estimating equations with a Poisson loglinear model were used to assess the impact of catheter ablation on VF episodes. The change in VF events before and after catheter ablation was compared with matched controls without ablation.
Results
From a total of 686 patients with an incident VT ablation procedure targeting LAVAs, 21 patients (age, 57±14 years; left ventricular ejection fraction, 30±10%) had both VT and VF and met inclusion criteria. A total of 80 VF events were recorded in the implantable cardioverter-defibrillator logs the 6 months preceding ablation. Complete and partial LAVA elimination was achieved in 11 (52%) and 10 (48%) patients, respectively. Catheter ablation was associated with a highly significant reduction in VF recurrences (<0.0001), which were limited to 3 (14%) patients at 6 months. The total number of VF events thereby decreased from 80 to 3, from a median of 1.0 (range, 1-29) to 0.0 (range, 0-1) in the 6 months before and after ablation, respectively. The reduction in VF events was significantly greater in patients with catheter ablation compared with 21 matched controls during 6-month periods following and preceding a baseline assessment (Poisson β-coefficient, 1.39; =0.0003).
Conclusions
Substrate-guided VT ablation targeting LAVAs may be associated with a significant reduction in recurrent VF, suggesting that VT and VF share overlapping arrhythmogenic substrates in patients with structural heart disease.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e006857
Kitamura T, Maury P, Lam A, Sacher F, ... Haissaguerre M, Jais P
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e006857 | PMID: 31760821
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Abstract

Avoidance of Vagal Response During Circumferential Pulmonary Vein Isolation: Effect of Initiating Isolation From Right Anterior Ganglionated Plexi.

Hu F, Zheng L, Liu S, Shen L, ... Fan X, Yao Y
Background
Circumferential pulmonary vein isolation (CPVI) often cause unavoidable vagal reflexes during procedure due to the coincidental modification of ganglionated plexus which are located on pulmonary vein (PV) antrum. The right anterior ganglionated plexi (RAGP) which located at superoanterior area of right superior PV antrum is an essential station to regulate the cardiac autonomic nerve activities and is easily coincidentally ablated during CPVI. The aim of this study is to assess the effect of RAGP ablation on vagal response (VR) during CPVI.
Methods
A total of 80 patients with paroxysmal atrial fibrillation who underwent the first time CPVI were prospectively enrolled and randomly assigned to 2 groups: group A (n=40), CPVI started with right PVs at RAGP site; group B (n=40): CPVI started with left PVs first, and the last ablation site is RAGP. Electrophysiological parameters include basal cycle length, A-H interval, H-V interval, sinus node recovery time, and atrioventricular node Wenckebach point were recorded before and after CPVI procedure.
Results
During CPVI, the positive VR were only observed on 1 patient in group A and 25 patients in group B (<0.001). A total of 21 patients with positive VR in group B needed for temporary ventricular pacing during procedure, while the only patient with positive VR in group A did not need for temporary ventricular pacing (<0.001). Compared with baseline, basal cycle length, sinus node recovery time, and atrioventricular node Wenckebach point were decreased significantly after CPVI procedure in both groups (all <0.05) and without differences between 2 groups.
Conclusions
Circumferential PV isolation initiated from RAGP could effectively inhibit VR occurrence and significantly increase heart rate during procedure.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007811
Hu F, Zheng L, Liu S, Shen L, ... Fan X, Yao Y
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007811 | PMID: 31760820
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Abstract

Impact of Bariatric Surgery on Atrial Fibrillation Type.

Donnellan E, Wazni O, Elshazly M, Kanj M, ... Jaber W, Saliba W

- Obesity is an independent risk factor for atrial fibrillation (AF) and is associated with a higher AF burden. Recently, weight loss has been found to be associated with a significant reversal in AF type. Bariatric surgery (BS) is associated with reductions in inflammation, left atrial and ventricular remodeling, sleep apnea, blood pressure and improved glycemic control, all of which may reduce AF burden. In this study we sought to determine the impact of BS on AF type.- We studied AF type prior to and following BS in 220 morbidly obese patients (BMI Ȧ5; 40 kg/m). All patients underwent extended outpatient cardiac rhythm monitoring within 12 months of BS and at least 1 year after BS.- There was a significant reduction in BMI following BS from 49.7±9 to 37.2±9 kg/m. Weight loss was greatest in the gastric bypass group with a mean % weight loss of 25% compared to 19% in patients who underwent sleeve gastrectomy and 16% following gastric banding (p<0.0001). Significant reductions in CRP, NT-proBNP, HbA1C and systolic blood pressure were observed in all 3 groups. Reversal of AF type occurred in 71% of patients following gastric bypass, 56% of patients who underwent sleeve gastrectomy and 50% of patients following gastric banding (p=0.004). On Cox proportional hazards analyses, % weight loss was significantly associated with AF reversal (p=0.0002).- Bariatric surgery is associated with significant reductions in weight, inflammatory markers, blood pressure and AF type and the beneficial effects appear to be greatest in those undergoing gastric bypass surgery. This study further exemplifies the importance of weight loss and risk factor modification in AF management.



Circ Arrhythm Electrophysiol: 14 Jan 2020; epub ahead of print
Donnellan E, Wazni O, Elshazly M, Kanj M, ... Jaber W, Saliba W
Circ Arrhythm Electrophysiol: 14 Jan 2020; epub ahead of print | PMID: 31940441
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Abstract

Physiological Left Bundle Branch Pacing Validated by Ultra-high Density Ventricular Mapping in a Swine Model.

Qian Z, Hou X, Wang Y, Jiang H, ... Wang B, Zou J

Left bundle branch (LBB) pacing was first reported by Huang et al in 2017 and following studies demonstrated that LBB pacing could provide favorable left ventricular (LV) electrical and mechanical synchrony. However, the mechanism of LV activation during LBB pacing is not fully understood. This study aimed to elucidate the detailed LV endocardial activation during LBB pacing in a swine model using an ultra-high density electroanatomic mapping system.



Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print
Qian Z, Hou X, Wang Y, Jiang H, ... Wang B, Zou J
Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print | PMID: 31935122
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Abstract

Protein Biomarkers and Risk of Atrial Fibrillation: The Framingham Heart Study.

Staerk L, Preis SR, Lin H, Lubitz SA, ... Benjamin EJ, Trinquart L

- Identification of protein biomarkers associated with incident atrial fibrillation (AF) may improve the understanding of the pathophysiology, risk prediction, and development of new therapeutics for AF. We examined the associations between 85 protein biomarkers and incident AF.- We included participants Ȧ5;50 years of age from the Framingham Heart Study Offspring and Third Generation cohorts, who had 85 fasting plasma proteins measured using Luminex xMAP platform. Hazard ratios (per 1 standard deviation increment of rank normalized biomarker [HR]) and 95% confidence intervals (CI) for incident AF were calculated using Cox regression models adjusted for age, sex, height, weight, current smoking, systolic blood pressure, diastolic blood pressure, hypertension treatment, diabetes, valvular heart disease, prevalent myocardial infarction, and prevalent heart failure. We used the False Discovery Rate to account for multiple testing.- The study sample comprised 3378 participants (54% women), with mean (SD) age of 61.5 (8.4) years. In total, 401 developed AF over a mean follow-up of 12.3±3.8 years. We observed lower hazard of incident AF associated with higher mean levels of insulin-like growth factor 1 (IGF1) (HR per 1 standard deviation increment in protein level = 0.84; 95% CI, 0.76-0.93), and higher hazard of incident AF associated with higher mean levels of both insulin-like growth factor-binding protein 1 (IGFBP1) (HR = 1.24; 95% CI, 1.1-1.39) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) (HR = 1.73; 95% CI, 1.52-1.96).- Decreased levels of IGF1 and increased levels of IGFBP1 and NT-proBNP were associated with higher risk of incident AF.



Circ Arrhythm Electrophysiol: 14 Jan 2020; epub ahead of print
Staerk L, Preis SR, Lin H, Lubitz SA, ... Benjamin EJ, Trinquart L
Circ Arrhythm Electrophysiol: 14 Jan 2020; epub ahead of print | PMID: 31941368
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Abstract

Association of Left Atrial High-Resolution Late Gadolinium Enhancement on Cardiac Magnetic Resonance with Electrogram Abnormalities Beyond Voltage in Patients with Atrial Fibrillation.

Kuo L, Zado E, Frankel D, Santangeli P, ... Nazarian S, Desjardins B

- Conflicting data have been reported on the association of left atrial (LA) late gadolinium enhancement (LGE) with atrial voltage in patients with atrial fibrillation. The association of LGE with electrogram (EGM) fractionation and delay remains to be examined. We sought to examine the association between LA LGE on cardiac magnetic resonance (CMR) and EGM abnormalities in patients with atrial fibrillation (AF).- High-resolution LGE CMR was performed prior to EGM mapping and ablation in AF patients. CMR features were quantified using LA myocardial signal intensity z-score (SI-Z), a continuous normalized variable, as well as a dichotomous LGE variable based upon previously validated methodology. EGM mapping was performed pre-ablation during sinus rhythm or LA pacing, and EGM locations were co-registered with CMR images. Analyses were performed using multi-level patient-clustered mixed effects regression models.- In the 40 AF patients (age 63.2 ± 9.2 years, 1312.3 ± 767.3 EGM points per patient), lower bipolar voltage was associated with higher SI-Z in patients who had undergone previous ablation (coefficient=-0.049, p<0.001), but not in ablation-naïve patients (coefficient=-0.004, p=0.7). LA EGM activation delay was associated with SI-Z in patients with previous ablation (SI-Z: coefficient=0.004, p<0.001; LGE: coefficient=0.04, p<0.001) but not in ablation-naïve patients. In contrast, increased LA EGM fractionation was associated with SI-Z (coefficient=0.012, p=0.03) and LGE (coefficient=0.035, P<0.001) only in ablation-naïve patients.- The association of LA LGE with voltage is modified by ablation. Importantly, in ablation naïve patients, atrial LGE is associated with EGM fractionation even in the absence of voltage abnormalities.



Circ Arrhythm Electrophysiol: 14 Jan 2020; epub ahead of print
Kuo L, Zado E, Frankel D, Santangeli P, ... Nazarian S, Desjardins B
Circ Arrhythm Electrophysiol: 14 Jan 2020; epub ahead of print | PMID: 31940244
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Abstract

Evaluation of ECG Imaging to Map Haemodynamically Stable and Unstable Ventricular Arrhythmias.

Graham AJ, Orini M, Zacur E, Dhillon G, ... Schilling RJ, Lambiase PD

- ECG Imaging (ECGI) has been used to guide treatment of ventricular ectopy and arrhythmias. However, the accuracy of ECGI in localizing the origin of arrhythmias during catheter ablation of ventricular tachycardia (VT) in structurally abnormal hearts remains to be fully validated.- During catheter ablation of VT, simultaneous mapping was performed using electro-anatomical mapping (EAM) (CARTO, Biosense-Webster) and ECGI (CardioInsight™, Medtronic) in 18 patients. Sites of entrainment, pace-mapping and termination during ablation were used to define the VT site of origin (SoO). Distance between SoO and the site of earliest activation on ECGI were measured using co-registered geometries from both systems. The accuracy of ECGI vs a 12-lead surface ECG algorithm was compared.- A total of 29 VTs were available for comparison. Distance between SoO and sites of earliest activation in ECGI was 22.6, 13.9-36.2 mm (median, first-third quartile). ECGI mapped VT sites of origin onto the correct AHA segment with higher accuracy than a validated 12-lead ECG algorithm (83.3% vs 38.9%, P=0.015).- This simultaneous assessment demonstrates that CardioInsight™ localizes VT circuits with sufficient accuracy to provide a region of interest for targeting mapping for ablation. Resolution is not sufficient to guide discrete radiofrequency lesion delivery via catheter ablation without concomitant use of an electro-anatomical mapping system, but may be sufficient for segmental ablation with radiotherapy.



Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print
Graham AJ, Orini M, Zacur E, Dhillon G, ... Schilling RJ, Lambiase PD
Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print | PMID: 31934784
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Abstract

Differences by Race/Ethnicity in the Prevalence of Clinically-detected and Monitor-detected Atrial Fibrillation: The Multi-Ethnic Study of Atherosclerosis.

Heckbert SR, Austin TR, Jensen PN, Chen LY, ... Kronmal RA, Psaty BM

- African Americans are consistently found to have a lower prevalence of clinically-detected atrial fibrillation (AF) than whites, despite a higher prevalence of major AF risk factors and higher risk of ischemic stroke. Long-term ambulatory electrocardiographic (ECG) monitors provide the opportunity for unbiased AF detection. We determined differences by race/ethnicity in the prevalence of clinically-detected AF and in the proportion with monitor-detected AF.- We conducted a cross-sectional analysis in the Multi-Ethnic Study of Atherosclerosis (MESA), a community-based cohort study that enrolled 6814 Americans free of clinically-recognized cardiovascular disease in 2000-2002. At the 2016-2018 examination, 1556 individuals participated in an ancillary study involving ambulatory ECG monitoring and had follow-up for clinically-detected AF since cohort entry.- Among 1556 participants, 41% were white, 25% African American, 21% Hispanic, and 14% Chinese; 51% were women; and the mean age was 74 years. The prevalence of clinically-detected AF after 14.4 years\' follow-up was 11.3% in whites, 6.6% in African Americans, 7.8% in Hispanics, and 9.9% in Chinese, and was significantly lower in African Americans than in whites, in both unadjusted and risk factor-adjusted analyses (adjusted rate difference, -6.6%, 95% CI -10.1, -3.1%, P < 0.001). By contrast, in the same individuals, the proportion with monitor-detected AF using a 14-day ambulatory ECG monitor was similar in the four race/ethnic groups: 7.1%, 6.4%, 6.9%, and 5.2%, respectively (compared with whites, all P > 0.5).- The prevalence of clinically-detected AF was substantially lower in African American than in white participants, without or with adjustment for AF risk factors. However, unbiased AF detection by ambulatory monitoring in the same individuals revealed little difference in the proportion with AF by race/ethnicity. These findings provide support for the hypothesis of differential detection by race/ethnicity in the clinical recognition of AF, which may have important implications for stroke prevention.



Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print
Heckbert SR, Austin TR, Jensen PN, Chen LY, ... Kronmal RA, Psaty BM
Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print | PMID: 31934795
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Abstract

Epicardial Connections Involving Pulmonary Veins: The Prevalence, Predic-tors and Implications for Ablation Outcome.

Barrio-López MT, Sanchez-Quintana D, Garcia Martinez J, Betancur A, ... Garcia F, Almendral J

- The presence of epicardial connections (ECs) between pulmonary veins (PVs) and other anatomical structures may hinder PV isolation. In this study we analyzed their prevalence, location, associated factors and clinical implications.- Five hundred and thirty-four consecutive patients with atrial fibrillation (AF) undergoing radiofrequency ablation were included. We considered that an EC was present if: 1) the first pass around the PV antrum did not produce PV isolation and 2) subsequent atrial activation during PV pacing showed that the earliest site was located away from the ablation line and later activation sites were observed near the ablation line. Clinical, and electrophysological variables were collected from all patients. Patients were followed during 12.9±9.4 months and any documented atrial tachyarrhythmia after the 3-month blanking period was classified as a recurrence.- Out of the 534 patients included, 72 (13.5%) were found to have 81 ECs. There was a significant association between the presence ECs and structural heart disease (SHD) (15.3% in patients without ECs vs. 36.5% in patient with ECs; p<0.001) and patent foramen ovale (PFO) (4.6% vs. 13.5%; p=0.002). The presence of a left common trunk was significantly associated with the absence of ECs (29.6% in patients without ECs vs 16.2% in patients with ECs; p=0.014). Patients with ECs had lower acute success in PV isolation compared with patients without ECs (99.1% vs. 86.1%; p<0.001). After adjusting for age, sex, type of AF, LA area, hypertension, SHD, presence of left common trunk, patent foramen ovale and time for AF diagnosis to the ablation we found a significantly higher risk of atrial tachyarrhythmia recurrences in patients with ECs compared with patients without ECs (hazard ratio: 1.7; 95% confidence inter-val: 1.1-2.9; p=0.04).- ECs between PVs and other adjacent structures are frequent in patient with AF (prevalence: 13.5%). SHD and a PFO are strongly associated with the presence of ECs. ECs reduce the acute and chronic success of PV isolation.



Circ Arrhythm Electrophysiol: 14 Jan 2020; epub ahead of print
Barrio-López MT, Sanchez-Quintana D, Garcia Martinez J, Betancur A, ... Garcia F, Almendral J
Circ Arrhythm Electrophysiol: 14 Jan 2020; epub ahead of print | PMID: 31940223
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Abstract

Mechanism of Recurrence of AT: Comparison between First Vs. Redo Procedures in a High-resolution Mapping System.

Takigawa M, Derval N, Martin CA, Vlachos K, ... Haïssaguerre M, Jaïs P

- Atrial fibrillation (AF) ablation related atrial tachycardia (AFA-rAT) is complex, and may demonstrate several forms: anatomical macroreenrant AT (AMAT), Non-AMAT, and focal AT. We aimed to elucidate the recurrence rate and mechanisms of AFA-rAT recurrence.- Among 147 patients with ATs treated with the Rhythmia™-system, 68 (46.3%) had recurrence at mean 4.2[2.9-11.6] months and 44 patients received a redo procedure. AT circuits in the first procedure were compared to those in the redo procedure.- Although mappable ATs were not observed in 7 patients, 68 ATs were observed in 37 patients during the first procedure: peri-mitral flutter (PMF) in 26 patients, roof-dependent macroreentrant-AT (RMAT) in 18, peri-tricuspid flutter (PTF) in 10, Non-AMAT in 14, and focal AT in 3. During the redo AT ablation procedure, 54 ATs were observed in 41 patients: PMF in 24, RMAT in 14, PTF in 1, Non-AMAT in 14, and focal AT in 1. Recurrence of PMF and RMAT was observed in 15/26 (57.7%) and 8/18 (44.4%) respectively, while PTF did not recur. Neither the same focal AT nor the same Non-AMAT were observed except in one case with septal scar related biatrial-AT. Epicardial structure-related ATs were involved in 18/24 (75.0%) in PMF, 4/14 (28.6%) in RMAT, and 4/14 (28.6%) in Non-AMAT. Out of 21 patients with a circuit including epicardial structures, 6 patients treated with ethanol-infusion in the vein of Marshall (VOM) did not show any AT-recurrence, though 8/15 (53.3%) treated with RF showed AT-recurrence (P=0.04).- Although high-resolution mapping may lead to correct diagnosis and appropriate ablation in the first procedure, the recurrence rate is still high. The main mechanism of AFA-rAT is the recurrence of PMF and RMAT, or Non-AMAT different from the first procedure. Epicardial structures (e.g. coronary sinus/VOM system) are often involved, and ethanol-infusion in the VOM may be an additional treatment.



Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print
Takigawa M, Derval N, Martin CA, Vlachos K, ... Haïssaguerre M, Jaïs P
Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print | PMID: 31937120
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Abstract

Higher Incidence of Asymptomatic Cerebral Emboli after Atrial Fibrillation Ablation Found with High-resolution Diffusion-weighted MRI.

Yu Y, Wang X, Li X, Zhou X, ... Yang B, Chen M

- Asymptomatic cerebral emboli (ACE) are commonly seen on cerebral MRI after atrial fibrillation (AF) ablation, but the incidence in previous studies varies widely. No data exists to compare the effects of different diffusion-weighted imaging (DWI) settings on detecting ablation-related ACE. This self-control study sought to compare the incidence and characteristics of ablation-related ACE between high-resolution DWI (hDWI) and conventional DWI (cDWI).- A total of 55 consecutive patients referred for AF ablation between December 2017 and September 2018 were enrolled. Patients underwent hDWI one day prior to ablation and repeated hDWI and cDWI within 48 hours post-ablation. The incidence, number, size, and location of ACE were compared between two DWI settings in the same patients.The hDWI revealed a higher incidence of acute ACE compared to cDWI (67.3% vs. 41.8% of patients, P <0.001) and significantly more ACE (106 vs. 45 lesions, P = 0.001). For ACE seen on both scans, the size measured by hDWI was larger (5.42 vs. 4.21 mm, P <0.001). No patients had any impaired neurocognitive performance during follow-up. Impaired left ventricular ejection fraction (LVEF) (P = 0.012) and low intraoperative activated clotting time (ACT) (P = 0.009) level were associated with the occurrence of ACE in a multivariate analysis.- High-resolution DWI revealed a higher incidence and greater details of post-ablation ACE in AF patients. MRI settings significantly impact the detection of ACE and should be considered when comparing incidence rates of ACE amongst different studies.- ClinicalTrials.gov; Unique Identifier: NCT01761188.



Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print
Yu Y, Wang X, Li X, Zhou X, ... Yang B, Chen M
Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print | PMID: 31937118
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Abstract

Differentiating Atrioventricular Reentry Tachycardia and AV Node Reentry Tachycardia Using Premature His Bundle Complexes.

Padanilam BJ, Ahmed AS, Clark BA, Gilge JL, ... Prystowsky EN, Steinberg LA

- Current maneuvers for differentiation of AV node reentry tachycardia (AVNRT) and atrioventricular reentry tachycardia (AVRT) lack sensitivity and specificity for AVRT circuits located away from the site of pacing. We hypothesized that a premature His complex (PHC) will always perturb AVRT because the His bundle is obligatory to the circuit. Further, AVNRT could not be perturbed by a late PHC (Ȧ4; 20 ms ahead of the His) due to the retrograde His conduction time. Earlier PHCs can advance the AVNRT circuit but only by a quantity less than the prematurity of the PHC.- High output pacing at the distal His location delivered PHCs. AVRT was predicted when late PHCs perturbed tachycardia or when earlier PHCs led to atrial advancement by an amount equal or greater than the degree of PHC prematurity.- Among the 73 SVTs, the test accurately predicted AVRT (n=29) and AVNRT (n=44) in all cases. Late PHC advanced the circuit in all 29 AVRTs and none of the AVNRTs (sensitivity and specificity 100%). With earlier PHCs, the degree of atrial advancement was equal or greater than the PHC prematurity in 26/29 AVRTs and none of the AVNRTs (90% sensitivity and 100% specificity). The mean prematurity of the PHC required to perturb AVNRT was 48 ms (range 28-70 ms) and the advancement less than the prematurity of the PHC (mean 32 ms; range 18-54 ms).- The responses to PHCs distinguished AVRT and AVNRT with 100% specificity and sensitivity.



Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print
Padanilam BJ, Ahmed AS, Clark BA, Gilge JL, ... Prystowsky EN, Steinberg LA
Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print | PMID: 31934781
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Abstract

Can the Durability of Pulmonary Vein Isolation be Predicted by the Time-to-Isolation in Second-generation Cryoballoon Ablation? Insight from the Results of Repeat Procedures.

Miyazaki S, Kajiyama T, Watanabe T, Nakamura H, ... Tada H, Iesaka Y

Second-generation cryoballoons (2-CBs) are widely used in atrial fibrillation (AF) ablation, however, the optimal freeze dose is still under debate. Recently, the time-to-isolation (TTI), which is the time until an acute pulmonary vein isolation (PVI), is noted based on clinical and experimental studies, and a TTI-guided strategy has been proposed. However, in real-world human CB procedures, the direct association between the TTI and PVI durability has not been well examined. We sought to investigate whether the TTI plus >120 second freezes, when the TTI is <60 seconds, accurately predicts a durable 2-CB ablation PVI.



Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print
Miyazaki S, Kajiyama T, Watanabe T, Nakamura H, ... Tada H, Iesaka Y
Circ Arrhythm Electrophysiol: 13 Jan 2020; epub ahead of print | PMID: 31935121
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Abstract

Myocarditis Causing Premature Ventricular Contractions: Insights From the MAVERIC Registry.

Lakkireddy D, Turagam MK, Yarlagadda B, Dar T, ... Gopinathannair R, Natale A
Background
Premature ventricular contractions are a common clinical presentation that drives further diagnostic workup. We hypothesize the presence of underlying inflammation is often unrecognized in these patients with a potential for continued disease progression if not diagnosed and treated early in the disease course.
Methods
This is a single-center, prospective study including 107 patients with frequent symptomatic premature ventricular contractions (>5000/24 h) and no known ischemic heart disease. Patients underwent a combination of laboratory testing, 18F-fluorodeoxyglucose positron emission tomography scan, cardiac magnetic resonance imaging, and biopsy. Patients were diagnosed with myocarditis based on a multidisciplinary approach and treated with immunosuppressive therapy.
Results
The mean age of the cohort was 57±15 years, 41% were males, and left ventricular ejection fraction was 47±11.8%. Positive positron emission tomography scan was seen in 51% (55/107), of which 51% (28/55) had preserved left ventricle function. Based on clinical profile, 18F-fluorodeoxyglucose-positron emission tomography imaging, cardiac magnetic resonance, and histological data 58% patients (32/55) received immunosuppressive therapy alone and 25.4% (14/55) received immunosuppressive therapy and catheter ablation. Optimal response was seen in 67% (31/46) over a mean follow-up of 6±3 months. In patients with left ventricle systolic dysfunction, 37% (10/27) showed an improvement in mean left ventricular ejection fraction of 13±6%.
Conclusions
Approximately 51% of patients presenting with frequent premature ventricular contractions have underlying myocardial inflammation in this cohort. 18F-fluorodeoxyglucose-positron emission tomography scan can be a useful modality for early diagnosis and treatment with immunosuppressive therapy in selected patients can improve clinical outcomes.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007520
Lakkireddy D, Turagam MK, Yarlagadda B, Dar T, ... Gopinathannair R, Natale A
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007520 | PMID: 31838913
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Abstract

Major Adverse Cardiovascular Events Associated with Post-Operative Atrial Fibrillation after Non-Cardiac Surgery: A Systematic Review and Meta-analysis.

AlTurki A, Marafi M, Proietti R, Cardinale D, ... Healey JS, Huynh T

- Post-operative atrial fibrillation (POAF) is a frequent occurrence after non-cardiac surgery. It remains unclear whether POAF is associated with an increased risk of major adverse events. We aimed to elucidate the risk of stroke, myocardial infarction and death associated with POAF following non-cardiac surgery by a meta-analysis of randomized controlled studies and observational studies.- We searched electronic databases from inception up to August 1st, 2019 for all studies that reported stroke or myocardial infarction in adult patients who developed POAF following non-cardiac surgery. We used random-effects models to summarize the studies.- The final analyses included 28 studies enrolling 2,612,816 patients. At one-month (ten studies), POAF was associated with an approximately three-fold increase in the risk of stroke (weighted mean 2.1% vs 0.7%) [odds ratio (OR) 2.82 (95% Confidence intervals (CI): 2.15-3.70); p< 0.001]. POAF was associated with approximately four-fold increase in the long-term risk of stroke with (weighted mean 2.0% vs 0.6%) (OR 4.12, 95% CI: 3.32-5.11; pȦ4;0.001) in eight studies with Ȧ5;12-month follow-up. There was a significant overall increase in the risk of stroke and myocardial infarction associated with POAF (weighted mean 2.5% vs 0.9%) (OR 3.44,95% CI: 2.38-4.98; p<0.001) and (weighted mean 12.6% vs 2.7%) (OR 4.02, 95% CI: 3.08-5.24; p<0.001) respectively. Furthermore, POAF was associated with a three-fold increase in all-cause mortality at 30 days (weighted mean 15.0% vs 5.4%) (OR: 3.36; 95% CI: 2.13-5.31; p<0.001).- POAF was associated with markedly higher risk of stroke, myocardial infarction and all-cause mortality following non-cardiac surgery. Future studies are needed to evaluate the impact of optimal cardiovascular pharmacotherapies to prevent POAF and to decrease the risk of major adverse events in these high-risk patients.



Circ Arrhythm Electrophysiol: 15 Jan 2020; epub ahead of print
AlTurki A, Marafi M, Proietti R, Cardinale D, ... Healey JS, Huynh T
Circ Arrhythm Electrophysiol: 15 Jan 2020; epub ahead of print | PMID: 31944855
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Abstract

Importance of Diastolic Function for the Prediction of Arrhythmic Death: A Prospective, Observer Blinded, Long-term Study.

Pezawas T, Burger AL, Binder T, Diedrich A

- Patients with ischemic or dilated cardiomyopathy and reduced left ventricular ejection fraction (LVEF) face a high risk for ventricular arrhythmias. Exact grading of diastolic function might improve risk stratification for arrhythmic death.- We prospectively enrolled 120 patients with ischemic, 60 patients with dilated cardiomyopathy and 30 patients with normal LVEF. Diastolic function was graded normal (N) or dysfunction grade I-III. Primary outcome parameter was arrhythmic death (AD) or resuscitated cardiac arrest (RCA).- Normal diastolic function was found in 23 (11%) patients, dysfunction grade I in 107 (51%), grade II in 31 (14.8%) and grade III in 49 (23.3%) patients, respectively. After an average follow-up of 7.0±2.6 years, AD or RCA was observed in 28 (13.3%) and 33 (15.7%) patients, respectively. Non-arrhythmic death was found in 41 (19.5%) patients. On Kaplan-Meier analysis, patients with dysfunction grade III had the highest risk for AD or RCA (p<0.001). This finding was independent from the degree of LVEF dysfunction and was observed in patients with LVEFȦ4;35% (p=0.001) and with LVEF>35% (p=0.014). Non-arrhythmic mortality was highest in patients with dysfunction grade III. This was true for patients with LVEFȦ4;35% (p=0.009) or >35% (p<0.001). In an adjusted model for relevant confounding factors, grade III dysfunction was associated with a 3.5-fold increased risk for AD or RCA in the overall study population (HR=3.52, p<0.001).- Diastolic dysfunction is associated with a high risk for AD or RCA regardless if LVEF is Ȧ4;35% or >35%. Diastolic function grading might improve risk stratification for AD.



Circ Arrhythm Electrophysiol: 15 Jan 2020; epub ahead of print
Pezawas T, Burger AL, Binder T, Diedrich A
Circ Arrhythm Electrophysiol: 15 Jan 2020; epub ahead of print | PMID: 31944144
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Abstract

Real-time Electrogram Analysis for Drivers of AtRial Fibrillation (RADAR): A Multi-Center FDA-IDE Clinical Trial of Persistent AF.

Choudry S, Mansour M, Sundaram S, Nguyen DT, ... Kessman P, Reddy VY

- Pulmonary vein isolation (PVI) is insufficient to treat all patients with persistent atrial fibrillation (AF), and effective adjunctive ablation strategies are needed. Ablation of AF drivers holds promise, but current technologies to identify drivers are limited by spatial resolution. In a single-arm, first-in-human, investigator-initiated FDA IDE study, we employed a novel system for real-time, high-resolution identification of AF drivers in persistent AF.- Persistent or longstanding persistent AF patients underwent ablation using the RADAR system in conjunction with a standard electroanatomical mapping system. After PVI, electrogram and spatial information was streamed and analyzed to identify driver domains to target for ablation.- Across 4 centers, 64 subjects were enrolled: 73% male, age 64.7±9.5 years, BMI 31.7±6.0 kg/m, LA size 54±10 mm, with persistent/longstanding persistent AF in 53 (83%) / 11 (17%), prior AF ablation (re-do group) in 26 (41%). After 12.6 ±} 0.8 months follow-up, 68% remained AF-free off all antiarrhythmics; 74% remained AF-free and 66% remained AF/AT/AFL-free on or off antiarrhythmic drugs. AF terminated with ablation in 35 patients (55%) overall and in 23/38 (61%) of de novo ablation patients. For patients with AF termination during ablation, 82% remained AF-free and 74% AF/AT/AFL free during follow-up on or off antiarrhythmic drugs. Patients undergoing first-time ablation generally had higher rates of freedom from AF than the re-do group.- This novel technology for panoramic mapping of AF drivers showed promising results in a persistent/long-standing persistent AF population. These data provide the scientific basis for a randomized trial.- clinicaltrials.org; Unique Identifier: NCT03263702; IDE#G170049.



Circ Arrhythm Electrophysiol: 15 Jan 2020; epub ahead of print
Choudry S, Mansour M, Sundaram S, Nguyen DT, ... Kessman P, Reddy VY
Circ Arrhythm Electrophysiol: 15 Jan 2020; epub ahead of print | PMID: 31944826
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Abstract

When Sinus Tachycardia Becomes Too Much: Negative Effects of Excessive Upright Tachycardia on Cardiac Output in Vasovagal Syncope, Postural Tachycardia Syndrome, and Inappropriate Sinus Tachycardia.

Stewart JM, Medow MS, Visintainer P, Sutton R

- Upright posture reduces venous return, stroke volume and cardiac output (CO) while causing reflex sinus rate (HR) increase. Yet, in inappropriate sinus tachycardia (IST), postural tachycardia syndrome (POTS), and vasovagal syncope (VVS) symptomatic excessive HR occurs. We hypothesized CO reaches maximum as function of HR in all.- We recruited 12 healthy controls, 9 IST, 30 VVS and 30 POTS patients (13-23years) selected randomly by disorder not by HR, each fulfilled appropriate diagnostic criteria. Subjects were instrumented for electrocardiography, beat-to-beat blood pressure, respiratory rate, CO-Modelflow algorithm, and central blood volume (CBV) from impedance cardiography; 10min data was collected supine; subjects were tilted head-up for =/<10min. We computed phase differences, ΔΦ, between fluctuations of HR (ΔHR) and CO (ΔCO) tabulating data when phases were synchronized, determined by a squared nonlinear phase synchronization index (PhSI) >0.5, describing extent/validity of CO/HR coupling. We graphed results supine, 1min-post-tilt-up, mid-tilt, and pre-tilt-down using polar coordinates (HR - radius, ΔΦ - angle) plotting cos(ΔΦ) vs HR to determine if transition HR exists at which in-phase shifts to anti-phase above which CO decreases when HR further increases.- At baseline HR, diastolic and mean arterial pressure in IST and POTS were higher vs controls. Upright HR increased most in POTS then IST and VVS, with diverse changes in CO, SVR, and CBV. Each patient grouping was separately and collectively analyzed for HR change showing transition from in-phase to anti-phase (ΔΦ) as HR increased: HR =115±6(IST),123±8(POTS),124±7(VVS), p=ns. Controls never reached transitional HR.- Excessive HR independently and equivalently reduces upright CO, in IST, POTS and VVS.



Circ Arrhythm Electrophysiol: 14 Jan 2020; epub ahead of print
Stewart JM, Medow MS, Visintainer P, Sutton R
Circ Arrhythm Electrophysiol: 14 Jan 2020; epub ahead of print | PMID: 31941353
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Abstract

Characterization of Structural Changes in Arrhythmogenic Right Ventricular Cardiomyopathy with Recurrent Ventricular Tachycardia after Ablation: Insights from Repeat Electroanatomic Voltage Mapping.

Briceño DF, Liang JJ, Shirai Y, Markman TM, ... Callans DJ, Marchlinski FE

Background - Data characterizing structural changes of arrhythmogenic right ventricular cardiomyopathy (ARVC) are limited.
Methods - Patients presenting with left bundle branch block ventricular tachycardia (VT) in the setting of ARVC with procedures separated by at least 9 months were included.
Results - Nineteen consecutive patients (84% males; mean age 39{plus minus}15 years [range, 20 to 76 years]) were included. All 19 patients underwent two detailed sinus rhythm electroanatomic endocardial voltage maps (average 385{plus minus}177 points per map; range, 93 to 847 points). Time interval between the initial and repeat ablation procedures was mean 50 {plus minus} 37 months (range 9-162). No significant progression of voltage was observed (bipolar: 38 cm2 [IQR 25, 54] vs. 53 cm2 [IQR 25, 65], p=0.09; unipolar: 116 cm2 [IQR 61, 209] vs. 159 cm2 [IQR 73, 204], p=0.36) for the entire study group. There was a significant increase in RV volumes (percentage increase = 28%; 206 ml [IQR 170, 253] vs. 263 ml [IQR 204, 294], p<0.001) for the entire study population. Larger scars at baseline but not changes over time were associated with a significant increase in RV volume (bipolar: Spearman\'s rho, 0.6965, p=0.006; unipolar: Spearman\'s rho, 0.5743, p=0.03). Most patients with progressive RV dilatation (8/14, 57%) had moderate (2 patients) or severe (6 patients) tricuspid regurgitation recorded at either initial or repeat ablation procedure.
Conclusions - In patients with ARVC presenting with recurrent VT, >10% increase in RV endocardial surface area of bipolar voltage consistent with scar is uncommon during the intermediate term. Most recurrent VTs are localized to regions of prior defined scar. Voltage indexed scar area at baseline but not changes in scar over time is associated with progressive increase in RV size, and is consistent with adverse remodeling but not scar progression. Marked tricuspid regurgitation is frequently present in patients with ARVC who have progressive RV dilation.



Circ Arrhythm Electrophysiol: 09 Jan 2020; epub ahead of print
Briceño DF, Liang JJ, Shirai Y, Markman TM, ... Callans DJ, Marchlinski FE
Circ Arrhythm Electrophysiol: 09 Jan 2020; epub ahead of print | PMID: 31922914
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Abstract

Pulsed Field Ablation vs Radiofrequency Ablation: Esophageal Injury in a Novel Model.

Koruth JS, Kuroki K, Kawamura I, Brose R, ... Dukkipati SR, Reddy VY

- Pulsed field ablation (PFA) can be myocardium-selective, potentially sparing the esophagus during left atrial ablation. In an in vivo porcine esophageal injury model, we compared the effects of newer biphasic PFA with radiofrequency ablation (RFA).- In 10 animals, under general anesthesia, the lower esophagus was deflected towards the inferior vena cava (IVC) using an esophageal deviation balloon, and ablation was performed from within the IVC at areas of esophageal contact. Four discrete esophageal sites were targeted in each animal: 6 animals received 8 PFA applications/site (2 kV, multispline catheter), and 4 animals received 6 clusters of irrigated RFA applications (30W x 30 seconds, 3.5mm catheter). All animals were survived to 25 days, sacrificed and the esophagus submitted for pathological examination, including 10 discrete histological sections/esophagus.- The animals weight increased by 13.7±6.2 and 6.8±6.3 % (p=0.343) in the PFA and RFA cohorts, respectively. No PFA animals (0 of 6, 0%) developed abnormal in-life observations, but 1 of 4 RFA animals (25%) developed fever and dyspnea. On necropsy, no PFA animals (0 of 6, 0%) demonstrated esophageal lesions. In contrast, esophageal injury occurred in all RFA animals (4 of 4, 100%; p=0.005): a mean of 1.5 mucosal lesions/animal (length - 21.8±8.9 mm, width - 4.9±1.4 mm) were observed, including one esophago-pulmonary fistula, and deep esophageal ulcers in the other animals. Histological examination demonstrated tissue necrosis surrounded by acute and chronic inflammation and fibrosis. The necrotic RFA lesions involved multiple esophageal tissue layers with evidence of arteriolar medial thickening and fibrosis of peri-esophageal nerves. Abscess formation and full-thickness esophageal wall disruptions were seen in areas of perforation/fistula.- In this novel porcine model of esophageal injury, biphasic PFA induced no chronic histopathological esophageal changes, while RFA demonstrated a spectrum of esophageal lesions including fistula and deep esophageal ulcers and abscesses.



Circ Arrhythm Electrophysiol: 23 Jan 2020; epub ahead of print
Koruth JS, Kuroki K, Kawamura I, Brose R, ... Dukkipati SR, Reddy VY
Circ Arrhythm Electrophysiol: 23 Jan 2020; epub ahead of print | PMID: 31977250
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Abstract

Renewal Theory as a Universal Quantitative Framework to Characterize Phase Singularity Regeneration in Mammalian Cardiac Fibrillation.

Dharmaprani D, Schopp M, Kuklik P, Chapman D, ... McGavigan AD, Ganesan AN
Background
Despite a century of research, no clear quantitative framework exists to model the fundamental processes responsible for the continuous formation and destruction of phase singularities (PS) in cardiac fibrillation. We hypothesized PS formation/destruction in fibrillation could be modeled as self-regenerating Poisson renewal processes, producing exponential distributions of interevent times governed by constant rate parameters defined by the prevailing properties of each system.
Methods
PS formation/destruction were studied in 5 systems: (1) human persistent atrial fibrillation (n=20), (2) tachypaced sheep atrial fibrillation (n=5), (3) rat atrial fibrillation (n=4), (5) rat ventricular fibrillation (n=11), and (5) computer-simulated fibrillation. PS time-to-event data were fitted by exponential probability distribution functions computed using maximum entropy theory, and rates of PS formation and destruction (λ/λ) determined. A systematic review was conducted to cross-validate with source data from literature.
Results
In all systems, PS lifetime and interformation times were consistent with underlying Poisson renewal processes (human: λ, 4.2%/ms±1.1 [95% CI, 4.0-5.0], λ, 4.6%/ms±1.5 [95% CI, 4.3-4.9]; sheep: λ, 4.4%/ms [95% CI, 4.1-4.7], λ, 4.6%/ms±1.4 [95% CI, 4.3-4.8]; rat atrial fibrillation: λ, 33%/ms±8.8 [95% CI, 11-55], λ, 38%/ms [95% CI, 22-55]; rat ventricular fibrillation: λ, 38%/ms±24 [95% CI, 22-55], λ, 46%/ms±21 [95% CI, 31-60]; simulated fibrillation λ, 6.6-8.97%/ms [95% CI, 4.1-6.7]; ≥0.90 in all cases). All PS distributions identified through systematic review were also consistent with an underlying Poisson renewal process.
Conclusions
Poisson renewal theory provides an evolutionarily preserved universal framework to quantify formation and destruction of rotational events in cardiac fibrillation.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007569
Dharmaprani D, Schopp M, Kuklik P, Chapman D, ... McGavigan AD, Ganesan AN
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007569 | PMID: 31813270
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Abstract

The Left Atrial Appendage Morphology Improves Prediction of Stagnant Flow and Stroke Risk in Atrial Fibrillation.

Yaghi S, Chang A, Ignacio G, Scher E, ... Atalay M, Song C

The left atrial appendage (LAA) is the most common site of thrombus formation in patients with atrial fibrillation. Therefore, better knowledge of the morphology, physiology, and function of the LAA may provide a better estimate of stroke risk. The LAA morphology is currently classified into 4 categories: chicken-wing (CW), windsock, cauliflower, and cactus. Chicken-wing is the most common and carries lower risk. This classification system, however, lacks consistent inter-rater reliability and correlation with stroke risk.



Circ Arrhythm Electrophysiol: 26 Jan 2020; epub ahead of print
Yaghi S, Chang A, Ignacio G, Scher E, ... Atalay M, Song C
Circ Arrhythm Electrophysiol: 26 Jan 2020; epub ahead of print | PMID: 31986073
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Abstract

Preclinical Evaluation of Pulsed Field Ablation: Electrophysiological and Histological Assessment of Thoracic Vein Isolation.

Koruth J, Kuroki K, Iwasawa J, Enomoto Y, ... Dukkipati SR, Reddy VY
Background
Pulsed field ablation (PFA) is a uniquely tissue-selective, nonthermal cardiac ablation modality. Delivery parameters such as the electrical waveform composition and device design are critical to PFA\'s efficacy and safety, particularly tissue specificity. In a series of preclinical studies, we sought to examine the electrophysiological and histological effects of PFA and compare the safety and feasibility of durable pulmonary vein and superior vena cava (SVC) isolation between radiofrequency ablation and PFA waveforms.
Methods
A femoral venous approach was used to gain right and left atrial access under general anesthesia in healthy swine. Baseline potentials in right superior pulmonary and inferior common vein and in SVC were assessed. Bipolar PFA was performed with monophasic (PFA) and biphasic (PFA) waveforms in 7 and 7 swine sequentially and irrigated radiofrequency ablation in 3 swine. Vein potentials were then assessed acutely, and at ≈10 weeks; histology was obtained.
Results
All targeted veins (n=46) were successfully isolated on the first attempt in all cohorts. The PFA waveform induced significantly less skeletal muscle engagement. Pulmonary vein isolation durability was assessed in 28 veins: including the SVC, durability was significantly higher in the PFA group (18/18 PFA, 10/18 PFA, 3/6 radiofrequency, =0.002). Transmurality rates were similar across groups with evidence of nerve damage only with radiofrequency. Pulmonary vein narrowing was noted only in the radiofrequency cohort. The phrenic nerve was spared in all cohorts but at the expense of incomplete SVC encirclement with radiofrequency.
Conclusions
In this chronic porcine study, PFA-based pulmonary vein and SVC isolation were safe and efficacious with demonstrable sparing of nerves and venous tissue. This preclinical study provided the scientific basis for the first-in-human endocardial PFA studies.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007781
Koruth J, Kuroki K, Iwasawa J, Enomoto Y, ... Dukkipati SR, Reddy VY
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007781 | PMID: 31826647
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Abstract

Impedance in the Diagnosis of Lead Malfunction.

Swerdlow CD, Koneru JN, Gunderson B, Kroll MW, Ploux S, Ellenbogen KA

Impedance is the ratio of voltage to current in an electrical circuit. Cardiac implantable electronic devices measure impedance to assess the structural integrity electrical performance of leads, typically using subthreshold pulses. We review determinants of impedance, how it is measured, variation in clinically-measured pacing and high-voltage impedance, and impedance trends as a diagnostic for lead failure and lead-device connection problems. We consider the differential diagnosis of abnormal impedance and the approach to the challenging problem of a single, abnormal impedance measurement. Present impedance provides a specific but insensitive diagnostic. For pacing circuits, we review the complementary roles of impedance and more sensitive oversensing diagnostics. Shock circuits lack a sensitive diagnostic. This deficiency is particularly important for insulation breaches, which may go undetected and present with short circuits during therapeutic shocks. We consider new methods for measuring impedance that may increase sensitivity for insulation breaches.



Circ Arrhythm Electrophysiol: 26 Jan 2020; epub ahead of print
Swerdlow CD, Koneru JN, Gunderson B, Kroll MW, Ploux S, Ellenbogen KA
Circ Arrhythm Electrophysiol: 26 Jan 2020; epub ahead of print | PMID: 31985260
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Abstract

Atrial Fibrillation-Mediated Cardiomyopathy.

Qin D, Mansour MC, Ruskin JN, Heist EK

AF-mediated cardiomyopathy (AMC) is an important reversible cause of heart failure that is likely underdiagnosed in today\'s clinical practice. AMC describes AF either as the sole cause for ventricular dysfunction or exacerbating ventricular dysfunction in patients with existing cardiomyopathy or heart failure. Studies suggest that irreversible ventricular and atrial remodeling can occur in AMC, making timely diagnosis and intervention critical to optimize clinical outcome. Clinical correlation between AF onset/burden and progression of cardiomyopathy/heart failure symptoms provides strong evidence for the diagnosis of AMC. Cardiac MRI, continuous cardiac monitoring, and biomarkers are important diagnostic tools. From the therapeutic standpoint, early data suggest that AF ablation may improve long-term outcomes in AMC patients compared with medical rate and rhythm control. Patients with more AF burden and less severe underlying structural heart disease are more likely to experience left ventricle function recovery with successful AF ablation. Despite recent advances, significant knowledge gaps exist in our understanding of the epidemiology, mechanisms, diagnosis, management strategies, and prognosis of AMC.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007809
Qin D, Mansour MC, Ruskin JN, Heist EK
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007809 | PMID: 31826649
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Abstract

Persistent Asthma is Associated with Increased Risk for Incident Atrial Fibrillation in the Multi-Ethnic Study of Atherosclerosis (MESA).

Tattersall MC, Dasiewicz AS, McClelland RL, Gepner AD, ... Hamdan MH, Stein JH

- Asthma and atrial fibrillation (AF) share an underlying inflammatory pathophysiology. We hypothesized that persistent asthmatics are at higher risk for developing AF and that this association would be attenuated by adjustment for baseline markers of systemic inflammation.- The Multi-Ethnic Study of Atherosclerosis is a prospective longitudinal study of adults free of cardiovascular disease at baseline. Presence of asthma was determined at exam 1. Persistent asthma was defined as asthma requiring use of controller medications. Intermittent asthma was defined as asthma without use of controller medications. Participants were followed for a median of 12.9 (interquartile range 10-13.6) years for incident AF. Multivariable Cox regression models were used to assess associations of asthma subtype and AF.- The 6,615 participants were a mean (standard deviation) 62.0 (10.2) years old, (47% male, 27% African-American, 12% Chinese, 22% Hispanic). AF incidence rates were 0.11 [95% CI 0.01, 0.12] events/10 person-years for non-asthmatics, 0.11 [95% CI 0.08, 0.14] events/10 person-years for intermittent asthmatics, and 0.19 [95% CI 0.12, 0.49] events/10 person-years for persistent asthmatics (log-rank p=0.008). In risk-factor adjusted models, persistent asthmatics had a greater risk of incident AF (hazard ratio [HR] 1.49 [95% CI 1.03-2.14], p=0.03). Interleukin 6 (IL-6, HR 1.26 [95% CI 1.13-1.42]), tumor necrosis factor-α receptor 1 (TNF-α R1, HR 1.09 [95% CI 1.08-1.11]) and D-Dimer (HR 1.10 [95% CI 1.02-1.20]) predicted incident AF, but the relationship between asthma and incident AF was not attenuated by adjustment for any inflammation marker (IL-6, C-reactive protein, TNF-α R1, D-dimer, fibrinogen).- In a large multiethnic cohort with nearly 13 years follow-up, persistent asthma was associated with increased risk for incident AF. This association was not attenuated by adjustment for baseline inflammatory biomarkers.



Circ Arrhythm Electrophysiol: 03 Feb 2020; epub ahead of print
Tattersall MC, Dasiewicz AS, McClelland RL, Gepner AD, ... Hamdan MH, Stein JH
Circ Arrhythm Electrophysiol: 03 Feb 2020; epub ahead of print | PMID: 32013555
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Abstract

Pulmonary Vein Isolation With a Novel Multielectrode Radiofrequency Balloon Catheter That Allows Directionally Tailored Energy Delivery: Short-Term Outcomes From a Multicenter First-in-Human Study (RADIANCE).

Reddy VY, Schilling R, Grimaldi M, Horton R, ... Abdelaal A, Mansour M
Background
Balloon catheters facilitate pulmonary vein (PV) isolation, but current technology is limited by either a single ablative element, potentially leading to over-ablation of thin and under-ablation of thick tissue, or prolonged procedure times. Visualized by electroanatomical mapping, a novel compliant radiofrequency balloon catheter with 10 irrigated, flexible electrodes can simultaneously and independently deliver energy. Herein, we evaluated the feasibility, safety, and short-term efficacy of this radiofrequency balloon in a multicenter, single-arm, first-in-human study.
Methods
Paroxysmal atrial fibrillation patients underwent PV isolation with the radiofrequency balloon delivered over-the-wire with a deflectable 13.5F sheath. Radiofrequency energy is delivered simultaneously from all electrodes-up to 30 s posteriorly and 60 s anteriorly. Esophageal temperature was monitored in all patients; the esophagus was also mechanically deviated in 10 patients.
Results
At 4 sites, 39 patients were treated by 9 operators. The radiofrequency balloon isolated all targeted PVs (152/152), 79.6% with a single application. Electrical reconnection occurred in only 7/150 PVs (4.7%) on adenosine/isoproterenol challenge. Mean procedure, balloon dwell, and fluoroscopy times were 101.6, 40.5, and 17.4 min, respectively. Esophagogastroduodenoscopy revealed asymptomatic esophageal erythema in 5 patients. Phrenic nerve palsy occurred in a patient in whom phrenic pacing was inadvertently omitted. At 3 months, imaging revealed no PV stenosis, and early atrial arrhythmia recurrence occurred in only 10/39 (25.6%) patients.
Conclusions
The compliant radiofrequency balloon can directionally tailor energy delivery for efficient, effective, and reasonably safe acute PV isolation.
Clinical trial registration
URL: https://www.clinicaltrials.gov. Unique identifier: ISRCTN 11764506.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007541
Reddy VY, Schilling R, Grimaldi M, Horton R, ... Abdelaal A, Mansour M
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007541 | PMID: 31826648
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Abstract

R-From-T as a Common Mechanism of Arrhythmia Initiation in Long QT Syndromes.

Liu MB, Vandersickel N, Panfilov AV, Qu Z
Background
Long QT syndromes (LQTS) arise from many genetic and nongenetic causes with certain characteristic ECG features preceding polymorphic ventricular tachyarrhythmias (PVTs). However, how the many molecular causes result in these characteristic ECG patterns and how these patterns are mechanistically linked to the spontaneous initiation of PVT remain poorly understood.
Methods
Anatomic human ventricle and simplified tissue models were used to investigate the mechanisms of spontaneous initiation of PVT in LQTS.
Results
Spontaneous initiation of PVT was elicited by gradually ramping up I to simulate the initial phase of a sympathetic surge or by changing the heart rate, reproducing the different genotype-dependent clinical ECG features. In LQTS type 2 (LQT2) and LQTS type 3 (LQT3), T-wave alternans was observed followed by premature ventricular complexes (PVCs). Compensatory pauses occurred resulting in short-long-short sequences. As I increased further, PVT episodes occurred, always preceded by a short-long-short sequence. However, in LQTS type 1 (LQT1), once a PVC occurred, it always immediately led to an episode of PVT. Arrhythmias in LQT2 and LQT3 were bradycardia dependent, whereas those in LQT1 were not. In all 3 genotypes, PVCs always originated spontaneously from the steep repolarization gradient region and manifested on ECG as R-on-T. We call this mechanism R-from-T, to distinguish it from the classic explanation of R-on-T arrhythmogenesis in which an exogenous PVC coincidentally encounters a repolarizing region. In R-from-T, the PVC and the T wave are causally related, where steep repolarization gradients combined with enhanced I lead to PVCs emerging from the T wave. Since enhanced I was required for R-from-T to occur, suppressing window I effectively prevented arrhythmias in all 3 genotypes.
Conclusions
Despite the complex molecular causes, these results suggest that R-from-T is likely a common mechanism for PVT initiation in LQTS. Targeting I properties, such as suppressing window I or preventing excessive I increase, could be an effective unified therapy for arrhythmia prevention in LQTS.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007571
Liu MB, Vandersickel N, Panfilov AV, Qu Z
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007571 | PMID: 31838916
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Abstract

Outcomes and Anticoagulation Use After Catheter Ablation for Atrial Fibrillation.

Freeman JV, Shrader P, Pieper KS, Allen LA, ... Peterson ED, Piccini JP
Background
Studies evaluating the effects of atrial fibrillation (AF) catheter ablation versus antiarrhythmic therapy on outcomes have shown mixed results. In addition, guidelines recommend continuing oral anticoagulation (OAC) after ablation for those at risk of stroke, but real-world data are lacking.
Methods
We evaluated outcomes including death, myocardial infarction, stroke or systemic embolism, intracranial bleeding, major bleeding, and hospitalization in patients undergoing AF ablation compared with a propensity score matched cohort of patients treated with anti-arrhythmic medications only in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation registries. Cox proportional hazards regression was performed to evaluate the association between AF ablation and outcomes. We then evaluated patterns of treatment with OAC among AF ablation patients.
Results
Among 21 595 patients, 1190 (6%) underwent de novo AF ablation. Our propensity score-matched cohort included 1087 patients who underwent AF ablation matched 1:1 with 1087 patients treated with antiarrhythmic medications only. There were no significant differences in the risk of all-cause and cardiovascular death, and most other major adverse cardiovascular and neurological events. AF catheter ablation was associated with an increased risk of all-cause hospitalization during follow-up (hazard ratio, 1.24 [95% CI, 1.05-1.46]), particularly in the first 3 months (the standard blanking period) after the procedure. Among those who underwent AF ablation with a CHADS VASc score ≥2 for men and ≥3 for women, 23% had OAC discontinued after ablation. Among those who discontinued OAC, the median time to discontinuation was 6.2 months.
Conclusions
In this large US national registry, we found no difference in adjusted rates of cardiovascular or all-cause death between patients treated with AF catheter ablation and antiarrhythmic medications only. Notably, discontinuation of OAC after ablation remains relatively common despite guideline recommendations for continued stroke prevention therapy in patients at risk of stroke.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007612
Freeman JV, Shrader P, Pieper KS, Allen LA, ... Peterson ED, Piccini JP
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e007612 | PMID: 31830822
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Abstract

Association of Follow-Up Care With Long-Term Death and Subsequent Hospitalization in Patients With Atrial Fibrillation Who Receive Emergency Care in the Province of Ontario.

Atzema CL, Yu B, Schull MJ, Jackevicius CA, ... Rochon PA, Austin PC
Background
Currently, 11% of patients seen in the emergency department for atrial fibrillation die within 1 year of the visit. Our objective was to examine the association of rapid (within 3 days), early (7 days), and basic (30 days) outpatient physician follow-up with short- and long-term outcomes in patients with atrial fibrillation discharged from an emergency department.
Methods
This retrospective cohort study included all adult patients discharged from one of the 163 emergency departments in Ontario, Canada with a primary diagnosis of atrial fibrillation, 2007 to 2014. We used a landmark analysis with propensity score matching, and logistic regression, to assess all-cause mortality and cardiovascular hospitalizations at 1 year and 90 days, 30-day return emergency visits, and 1-year oral anticoagulation prescription fills.
Results
In the 10 657 patients with rapid follow-up care who were propensity score matched to a patient with follow-up between days 4 and 7, the hazard of a return emergency visit was reduced by 11% (HR, 0.89 [95% CI, 0.80-0.98]). It was not associated with mortality or hospitalization. In the 17 234 patients with early follow-up who were matched to a patient with care between days 8 and 30, the rate of 1-year mortality was 11% lower (HR, 0.89 [95% CI, 0.81-0.97]) and 1-year hospitalization was 6% lower (HR, 0.94 [95% CI, 0.89-1.00]). Relative to no 30-day care, basic follow-up care was associated with an increased hazard of 90-day hospitalization (HR, 1.32 [95% CI, 1.12-1.56]) but was no longer associated with mortality. In patients with early follow-up, the odds of filling an oral anticoagulation prescription a year later were 64% higher than those without it (OR, 1.64 [95% CI, 1.54-1.78]).
Conclusions
Compared with follow-up care between days 8 and 30, follow-up within a week after discharge from an emergency department with atrial fibrillation was associated with a reduction in the rate of death and hospitalization within 1 year, an association that was not present with 30-day follow-up.



Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e006498
Atzema CL, Yu B, Schull MJ, Jackevicius CA, ... Rochon PA, Austin PC
Circ Arrhythm Electrophysiol: 29 Nov 2019; 12:e006498 | PMID: 31838915
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