Introduction Myriad cardiovascular manifestations have been reported with COVID‐19. We previously reported that failure of PR interval shortening with increasing heart rate (HR) in patients with COVID‐19 is associated with adverse outcomes. Here, we report on heart rate variability (HRV) and clinical outcomes in patients with chronic atrial fibrillation (cAF) hospitalized for COVID‐19. Methods A retrospective review of admitted COVID‐19 patients with cAF between 1 March 2020 to 30 June 2020 was performed. HRV in cAF was compared during pre‐COVID‐19 and COVID‐19 admissions; we selected pre‐COVID‐19 ECGs with HRs that were within 10 beats per minute of the COVID‐19 ECGs. Mean HR and each RR interval were recorded. Time‐domain measurements of HR variability were then calculated (SDSD, RMSSD, pNN50). Clinical outcomes during COVID‐19 were correlated to indices of HRV. Results A total of 184 ECGs (95 pre‐COVID‐19, 89 COVID‐19) from 38 cAF in‐patients were included. Mean age 78.6 ± 11.4 years, male 44.7%. The mean number of ECGs analyzed per patient pre‐COVID‐19 was 2.50 and during COVID‐19 was 2.34. Comparing pre‐COVID‐19 versus COVID‐19 ECGs showed: mean HR (95.9 ± 24.3 vs. 101.6 ± 22.8 BPM; P = .10), SDSD (109.0 ± 50.6 vs. 90.3 ± 37.2 ms; P < .01), RMSSD (184.1 ± 80.4 vs. 147.3 ± 59.8 ms; P < .01), pNN50 (73.8 ± 16.3 vs. 65.6 ± 16.6%; P < .01). Patients who had a smaller pNN50 during a COVID‐19 admission had increased mortality (50.0% vs. 14.3%; log‐rank test P = .02). Conclusion In patients with cAF, the HRV was reduced during COVID‐19 compared with prior illnesses at similar average heart rates. Patients with the most depressed HRV as measured by pNN50 had an associated increase in mortality compared with patients whose HRV was preserved.

Aims The value of additional ablation beyond pulmonary vein isolation for atrial fibrillation (AF) ablation is unclear, especially for persistent AF. The optimal target for substrate modification to improve outcomes is uncertain. We investigate the utility of low-voltage area (LVA) substrate modification in patients undergoing catheter ablation for AF. Methods This meta-analysis was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Medline, Scopus and Cochrane Central Register of Controlled Trials were systematically searched to identify relevant studies. Risk of bias was assessed using the Cochrane risk of bias tool. Only randomized studies were included. AF patients who underwent catheter ablation with voltage-guided substrate modification targeting LVA (LVA group) vs. conventional ablation approaches not targeting LVA (non-LVA group) were compared. Results Four studies comprising 539 patients were included (36% female). Freedom from arrhythmia (FFA) in patients with persistent AF was greater in the LVA group [risk ratio (RR) 1.30; 95% confidence interval (CI) 1.03–1.64]. There was no difference in FFA in patients with paroxysmal AF between groups (RR 1.30; 95% CI 0.89–1.91). There was no difference in total procedural time (mean difference −17.54 min; 95% CI −64.37 to 29.28 min) or total ablation time (mean difference −36.17 min; 95% CI −93.69 to 21.35 min) in all included patients regardless of AF type between groups. There was no difference in periprocedural complications between groups in all included patients regardless of AF type (RR 0.93; 95% CI 0.22–3.82). Conclusion This meta-analysis demonstrates improved FFA in persistent AF patients who underwent voltage-guided substrate modification targeting LVA.

Introduction High‐power short‐duration (HPSD) ablation is a novel strategy using contact force‐sensing catheters optimized for power‐controlled radiofrequency ablation for atrial fibrillation (AF). This study investigates the outcomes of HPSD (50 W delivered for up to 15 s, Lesion Size Index of 5–6) compared to standard‐power standard‐duration (SPSD) (20–25 W until 400–500 gram seconds, up to 60 s) and temperature‐controlled noncontact (TCNC) (20‐40 W up to 60 s of ablation) settings. Methods We studied consecutive cases of patients with AF undergoing pulmonary vein isolation with TCNC, SPSD, and HPSD between January 7th, 2013 and January 11th, 2019. Procedural data collected include time to isolate the left (LPVT) and right pulmonary veins (RPVT), total ablation time (TAT), and radiofrequency ablation delivery time (RADT). Clinical data collected include sinus rhythm maintenance postprocedure. Results One hundred and seventy‐one patients were studied (44 TCNC, 51 SPSD, 76 HPSD). RADT was shorter when comparing HPSD to SPSD (25 vs. 41 min; p < .01), HPSD to TCNC (25 vs. 76 min; p < .01), and SPSD to TCNC groups (41 vs. 76 min; p < .01). TAT, LPVT, and RPVT were reduced between HPSD versus SPSD, HPSD versus TCNC, and SPSD versus TCNC groups, respectively (p < .01). There was no difference in sinus rhythm maintenance by Kaplan–Meier survival analysis (log rank test p = .12), after 3 or 12 months between groups overall, and when stratified by AF type, left atrial volume, CHA2DS2‐VASc score, or left ventricular ejection fraction. Conclusion AF ablation with HPSD reduced procedure times with similar sinus rhythm maintenance compared to SPSD and TCNC.

Background Catheter ablation for atrial fibrillation (AF) is a proven alternative to pharmacologic rhythm control in patients with heart failure with reduced ejection fraction (HFrEF). Whether outcomes differ in patients with heart failure with preserved ejection fraction (HFpEF) is of interest. Methods Medline, Scopus, and Cochrane Central Register of Controlled Trials were systematically searched to identify relevant studies. Primary efficacy outcomes of interest include atrial arrythmia recurrence and repeat ablation. Harm outcomes of interest include all‐cause mortality, all‐cause hospitalizations, cardiovascular hospitalizations, stroke/transient ischemic attack, and cardiac tamponade. Results We included 7 observational studies comprising 2554 patients with HFpEF who underwent catheter ablation for AF. When comparing patients with HFpEF versus without HF, there was no significant difference in atrial arrhythmia recurrence (risk ratio [RR] 1.39; 95% confidence interval [CI] 0.91–2.13), stroke or transient ischemic attack (TIA) (RR 0.47; 95% CI 0.03–6.54), or cardiac tamponade (RR 1.20; 95% CI 0.12–12.20). When comparing patients with HFpEF versus HFrEF, there was no significant difference in atrial arrhythmia recurrence (RR 1.12; 95% CI 0.92–1.37), repeat ablation (RR 1.19; 95% CI 0.74–1.93), all‐cause mortality (RR 0.87; 95% CI 0.67–1.13), all‐cause hospitalizations (RR 1.10; 95% CI 0.94–1.30), cardiovascular hospitalizations (RR 0.83; 95% CI 0.69–1.01), stroke or TIA (RR 0.81; 95% CI 0.29–2.25), or cardiac tamponade (RR 0.98; 95% CI 0.19–5.16). Conclusions Non‐randomized studies suggest that catheter ablation for AF in patients with HFpEF is associated with similar arrythmia‐free survival and safety profile when compared to patients with HFrEF or without heart failure.