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Background: The wearable cardioverter-defibrillator (WCD) prevents sudden cardiac death due to ventricular tachycardia (VT) or ventricular fibrillation (VF) but does not pace for post-shock asystole (PS-A) or bradycardia (PS-B;<50 beats/ min)., Objectives: The purpose of this study was to assess PS-A and PS-B in patients dying out of hospital (OOH) while wearing a WCD., Methods: The database of the U.S. Food and Drug Administration Manufacturers and User Facility Device Experience (MAUDE) was queried for manufacturers' reports of OOH deaths while patients were wearing a WCD. Excluded were patients who did not receive a shock or were initially shocked for asystole or during resuscitation., Results: From January 2017 to March 2022, 313 patients received an initial WCD shock for VF (n = 150), VT (n = 90), and non-VF/VT rhythms (n = 73). PS-A occurred in 204 patients (65.2%), and PS-B occurred in 111 (35.5%); 85 (41.7%) PS-A patients also had PS-B. Most PS-A patients (n = 185; 90.7%) had an initial shocked rhythm of VF or VT, but 19 patients (9.3%) were initially inappropriately shocked for atrial fibrillation/supraventricular tachycardia (n = 7) and idioventricular (n = 8) or sinus (n = 4) rhythm. PS-A occurred after the first WCD shock in 118 (63.8%) and after the first, second, or third shocks in 159 patients (85.9%). Seven patients had post-shock heart block. Eight patients had permanent pacemakers; 1 became nonfunctional after 1 shock, and 7 showed noncapture and/or asystole after 1 to 4 shocks., Conclusions: Post-shock asystole appears to be common in patients who die OOH after being shocked by a WCD for VF or VT. PS-A also occurs after inappropriate WCD shocks for non-VF/VT rhythms. Implanted pacemakers may not prevent PS-A after a WCD shock. WCD backup pacing should be explored., Competing Interests: Funding Support and Author Disclosures The Minneapolis Heart Institute Foundation funded this study. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The LifeVest® wearable cardioverter-defibrillator (WCD) prevents sudden cardiac death in at-risk patients who are not candidates for an implantable defibrillator. The safety and efficacy of the WCD may be impacted by inappropriate shocks (IAS)., Objective: The purpose of this study was to assess the causes and clinical consequences of WCD IAS in survivors of IAS events., Methods: The Food and Drug Administration's Manufacturers and User Facility Device Experience database was searched for IAS adverse events (AE) that were reported during 2021 and 2022., Results: A total of 2568 IAS-AE were found (average number of IAS per event: 1.5 ± 1.9; range 1-48). IAS were caused by tachycardias (1255 [48.9%]), motion artifacts (840 [32.7%]), and oversensing (OS) of low-level electrical signals (473 [18.4%]) (P <.001). Tachycardias included atrial fibrillation (AF) (828 [32.2%]), supraventricular tachycardia (SVT) (333 [13.0%]), and nonsustained ventricular tachycardia/fibrillation (NSVT/VF) (87 [3.4%]). Activities responsible for motion-induced IAS included riding a motorcycle, lawnmower, or tractor (n = 128). In 19 patients, IAS induced sustained ventricular tachycardia or ventricular fibrillation that subsequently were terminated by appropriate WCD shocks. Thirty patients fell and suffered physical injuries. Conscious patients (n = 1905) did not use the response buttons to abort shocks (47.9%) or used them improperly (20.2%). IAS resulted in 1190 emergency room visits or hospitalizations, and 17.3% of patients (421/2440) discontinued the WCD after experiencing IAS, especially multiple IAS., Conclusions: The LifeVest WCD may deliver IAS caused by AF, SVT, NSVT/VF, motion artifacts, and oversensing of electrical signals. These shocks may be arrhythmogenic, result in injuries, precipitate WCD discontinuation, and consume medical resources. Improved WCD sensing, rhythm discrimination, and methods to abort IAS are needed., (Copyright © 2023. Published by Elsevier Inc.)

Background: Ablation of persistent atrial fibrillation (AF) remains challenging. Identification and ablation of localized AF drivers may offer the possibility for improved outcomes. Ripple map is a novel software algorithm that may allow improved localization of possible AF drivers through the whole chamber graphical display of continuously recorded bipolar electrograms. The objective of this study was to determine whether regions of high-frequency Ripple activation (HFRA) observed on Ripple map provide useful ablation targets in patients with persistent AF., Methods and Results: Consecutive patients underwent the first-time ablation of persistent AF (n = 162) using a standard stepwise (n = 105) or a Ripple map guided approach (n = 57). Ripple map guided patients underwent pulmonary vein antral isolation followed by ablation of HFRA sites. Acute termination of AF was observed in 91.2% of the Ripple-guided patients vs 52.4% in the stepwise approach, P < .0001. Following a single ablation procedure, after 18 months 98.2% of Ripple map guided patients were free of AF, compared with 81.4% of standard stepwise ablation (P = .005). Freedom from atrial tachycardia (54.4% Ripple map vs 52.4% standard, P = .9) or any atrial arrhythmia (52.6% Ripple map vs 39.0% standard, P = .10) did not differ between the two strategies. In a subset analysis (n = 30 of 56), Ripple map regions corresponded to sites with spatiotemporal dispersion in all atrial locations. No differences were observed in the rate of procedural complications., Conclusions: Ablation of HFRA sites identified with Ripple map resulted in a higher rate of acute termination and improved freedom from AF compared to a standard stepwise approach., (© 2019 The Authors. Journal of Cardiovascular Electrophysiology Published by Wiley Periodicals, Inc.)

Background: Atrial fibrillation (AF) and atrial flutter (AFL) are associated with increased risk of stroke and mortality after transcatheter aortic valve replacement (TAVR). Many episodes of new-onset AF/AFL (NOAF) occur after hospital discharge and may not be clinically apparent. Pacemakers can detect subclinical episodes of rapid atrial rate, which correlate with electrocardiographically documented AF., Methods: From 2012 to 2017, patients who underwent pacemaker implantation after TAVR were reviewed, and pacemaker data from device checks were analyzed for detection of NOAF. Patients with prior AF/AFL were excluded. Secondary outcomes were mortality and ischemic stroke., Results: A total of 172 patients underwent TAVR and pacemaker implantation, and 95 were without pre-existent AF/AFL. Over a median follow-up of 15 months, a total of 24 patients had NOAF (25%), of which 10 patients (10.5%) had manifest NOAF detected on electrocardiography, and 14 patients (14.7%) had subclinical NOAF first identified on device interrogation. The cumulative incidence of mortality was 16.7% for NOAF and 15.5% for normal sinus rhythm (P=.83). The cumulative incidence of stroke was 12.5% for NOAF and 1.4% for normal sinus rhythm (P=.04). Subclinical NOAF patients were less likely to be started on anticoagulation compared with manifest NOAF patients (70% vs 15.3%, respectively; P=.02)., Conclusion: Subclinical NOAF is common after TAVR, usually occurs months after hospital discharge, and is associated with lack of anticoagulation therapy and increased risk of stroke. Prolonged surveillance of subclinical NOAF may be warranted after TAVR.

Background: Limited medical options are available for rhythm control in patients with atrial fibrillation (AF) and hypertrophic cardiomyopathy (HCM). There are no published reports of dofetilide use in this population., Methods: A retrospective chart review was conducted on 1,404 patients loaded on dofetilide for AF suppression at the Cleveland Clinic from 2008 to 2012, 25 of whom were found to have HCM., Results: The HCM cohort was 32% female, 76% with persistent AF, mean age of 59 ± 10 years, and mean ejection fraction of 54 ± 9 %. Of the 25 patients, 21 were discharged on dofetilide, three discontinued during loading due to QTc prolongation, and one due to inefficacy. There were no adverse events during loading. Of those discharged on dofetilide, 11/21 (52%) were still on it at a median follow-up of 396 (198, 699) days at the time of the chart review. For those in whom it was discontinued, the median time on the drug was 301 (111, 738) days. Of the 10 patients who discontinued dofetilide during follow-up, six were due to inefficacy, one postablation, one postheart transplant, one due to death secondary to lung cancer, and one due to worsening edema., Conclusions: Dofetilide was well tolerated in this group of patients with AF and HCM and it facilitated management of AF in 21/25 (84%) patients. Further research is needed to assess the safety and efficacy of dofetilide in order to develop evidence-based guidelines for the pharmacological management of AF in this population., (© 2018 Wiley Periodicals, Inc.)

Background: Pulmonary vein isolation (PVI) for atrial fibrillation is associated with a transient increased risk of thromboembolic and hemorrhagic events. We hypothesized that dabigatran can be safely used as an alternative to continuous warfarin for the periprocedural anticoagulation in PVI., Methods and Results: A total of 999 consecutive patients undergoing PVI were included; 376 patients were on dabigatran (150 mg), and 623 patients were on warfarin with therapeutic international normalized ratio. [corrected] Dabigatran was held 1 to 2 doses before PVI and restarted at the conclusion of the procedure or as soon as patients were transferred to the nursing floor. Propensity score matching was applied to generate a cohort of 344 patients in each group with balanced baseline data. Total hemorrhagic and thromboembolic complications were similar in both groups, before (3.2% versus 3.9%; P=0.59) and after (3.2% versus 4.1%; P=0.53) matching. Major hemorrhage occurred in 1.1% versus 1.6% (P=0.48) before and 1.2% versus 1.5% (P=0.74) after matching in the dabigatran versus warfarin group, respectively. A single thromboembolic event occurred in each of the dabigatran and warfarin groups. Despite higher doses of intraprocedural heparin, the mean activated clotting time was significantly lower in patients who held dabigatran for 1 or 2 doses than those on warfarin., Conclusions: Our study found no evidence to suggest a higher risk of thromboembolic or hemorrhagic complications with use of dabigatran for periprocedural anticoagulation in patients undergoing PVI compared with uninterrupted warfarin therapy.

Introduction: Safety of THERMOCOOL SMARTTOUCH® SF (STSF) catheter for drug-refractory paroxysmal atrial fibrillation (PAF) ablation was demonstrated in the SMART SF Trial. Limited information is available on real-world procedural efficiency and concerns remain on safety of the porous-tip catheter. Hypothesis: We report on real-world procedural data and clinical benefit associated with fluid delivery with STSF compared to THERMOCOOL SMARTTOUCH® Catheter (ST). Methods: Consecutive PAF patients undergoing first time ablation, guided by CARTO VISITAG™ Module, were included (ST: n=102, STSF: n=71). The primary endpoint was composite heart failure presentation via hospital/ER/clinical visit and diuretic use within 30 days of procedure. The primary efficiency objective was comparison of fluid delivery and Foley catheter use between catheters. Results: Within the 3-year period between June 2014 and September 2017, 173 PAF patients were treated. Baseline characteristics were similar between groups. There were no differences in primary endpoints between groups. One cerebrovascular accident 14 days post-procedure was reported in the ST group. No complications were reported in the STSF group. Procedure time was short and similar between groups, while fluoroscopy time, fluid delivery, and Foley catheter use were significantly lower in the STSF group (Table). Conclusions: Compared to PAF ablation with ST, ablation with STSF resulted in lower fluid delivery and Foley catheter use, with similar safety and procedure time. Fluoroscopy reduction is likely attributed to purposeful workflow change to reduce radiation exposure. [ABSTRACT FROM AUTHOR]