Ablation of atrial fibrillation in an ambulatory outpatient setting.

Background: The safety of atrial fibrillation (AF) ablation in an ambulatory outpatient center has not previously been reported. Objective: The aim of this study is to report the feasibility and safety of AF ablation in an ambulatory setting. Methods: We identified all AF ablations performed at the Alaska Heart and Vascular Institute's ambulatory center since program initiation to current day using billing records. Procedural complications, postoperative utilization of hospital services, and emergency room (ER) utilization were captured by chart review. Results: A total of 476 patients underwent pulmonary vein isolation in the ambulatory setting over a 6.3-year period. Patients' average age was 58 ± 9.3 years, body mass index was 32.9 kg/m2, and the CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category) score was 1.7. For 85%, this was the first AF ablation, and 55% had paroxysmal AF. Cryoablation was used in 85%. A combined primary safety outcome capturing potentially unstable perioperative safety events occurred in 1.5% of patients, all of whom were stabilized prior to hospital transfer. A total of 1.5% of patients required same-day hospital services, with another 1.5% returning to the ER within 24 hours. A total of 96% of patients did not require hospital services within 24 hours of ablation. The 30-day ER utilization was 13.7%, similar to published data of same-day discharge of AF ablation done in the hospital setting. There were no emergent cardiac surgical interventions and no mortality events. Conclusion: Catheter ablation for AF in the ambulatory setting is both feasible and safe in this large single-center experience. More studies are needed to confirm this next frontier in catheter ablation for AF.

A wearable cardioverter defibrillator with a low false alarm rate.

INTRODUCTION: A wearable cardioverter defibrillator (WCD) is indicated in appropriate patients to reduce the risk for sudden cardiac death. Challenges for patients wearing a WCD have been frequent false shock alarms primarily due to electrocardiogram noise and wear discomfort. The objective of this study was to test a contemporary WCD designed for reduced false shock alarms and improved comfort. METHODS: One hundred and thirty patients with left ventricular ejection fraction ≤40% and an active implantable cardioverter defibrillator (ICD) were fitted with the ASSURE WCD (Kestra Medical Technologies) and followed for 30 days. WCD detection was enabled and shock alarm markers recorded, but shocks and shock alarms were disabled. All WCD episodes and ICD ventricular tachycardia/ventricular fibrillation (VT/VF) episodes were adjudicated. The primary endpoint was the false-positive shock alarm rate with a performance goal of 1 every 3.4 days (0.29 per patient-day). RESULTS: Of 163 WCD episodes, 4 were VT/VF and 159 non-VT/VF (121 rhythms with noise, 32 uncertain with noise, 6 atrial flutter without noise). Only three false-positive shock alarm markers were recorded; one false-positive shock alarm every 1333 patient-days (0.00075 per patient-day, 95% confidence interval: 0.00015-0.00361; p < .001). No ICD recorded VT/VF episodes meeting WCD detection criteria (≥170 bpm for ≥20 s) were missed by the WCD during 3501 patient-days of use. Median wear was 31.0 days (interquartile range [IQR] 2.0) and median daily use 23.0 h (IQR 1.7). Adverse events were mostly mild: skin irritation (19.4%) and musculoskeletal discomfort (8.5%). CONCLUSION: The ASSURE WCD demonstrated a low false-positive shock alarm rate, low patient-reported discomfort, and no serious adverse events.

Continuous ECG monitoring versus mobile telemetry: A comparison of arrhythmia diagnostics in human- versus algorithmic-dependent systems.

BACKGROUND: Clinicians rarely scrutinize the full disclosure of a myriad of FDA-approved long-term rhythm monitors, and they rely on manufacturers to detect and report relevant rhythm abnormalities. OBJECTIVE: The objective of this study is to compare the diagnostic accuracy between mobile cardiac telemetry (MCT), which uses an algorithm-based detection strategy, and continuous long-term electrocardiography (LT-ECG) monitoring, which uses a human-based detection strategy. METHODS: In an outpatient arrhythmia clinic, we enrolled 50 sequential patients ordered to wear a 30-day MCT, to simultaneously wear a continuous LT-ECG monitor. Periods of concomitant wear of both devices were examined using the associated report, which was over-read by 2 electrophysiologists. RESULTS: Forty-six of 50 patients wore both monitors simultaneously for an average of 10.3 ± 4.4 days (range: 1.2-14.8 days). During simultaneous recording, patients were more often diagnosed with arrhythmia by LT-ECG compared to MCT (23/46 vs 11/46), P = .018. Similarly, more arrhythmia episodes were detected during simultaneous recording with the LT-ECG compared to MCT (61 vs 19), P < .001. This trend remained consistent across arrhythmia subtypes, including ventricular tachycardia (13 patients by LT-ECG vs 7 by MCT), atrioventricular (AV) block (3 patients by LT-ECG vs 0 by MCT), and AV node reentrant tachycardia (2 patients by LT-ECG vs 0 by MCT). Atrial fibrillation (AF) was documented by both monitors in 2 patients; however, LT-ECG monitoring captured 4 additional AF episodes missed by MCT. CONCLUSION: In a time-controlled, paired analysis of 2 disparate rhythm monitors worn simultaneously, human-dependent LT-ECG arrhythmia detection significantly outperformed algorithm-based MCT arrhythmia detection.

Recent developments in the subcutaneous ICD.

The subcutaneous implantable cardioverter-defibrillator (ICD) was developed as a simple device to reduce the morbidity of ICD therapy while providing a comparable reduction in sudden death from ventricular fibrillation. This review highlights the differences compared to the traditional ICD. It includes recent data on safety and efficacy, as well as best practices on screening and programming, and discusses expected future developments.