William Whang

and 1 more

Response to letter re: ‘Premature Ventricular Complexes after Catheter Ablation for Atrial Fibrillation: Accounting For Regression to the Mean’William Whang, MD1 and Alex Choy, MD21Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY; william.whang@mountsinai.org2Department of Medicine, University of Chicago, Chicago, IL; a.choy10@gmail.comCorresponding author: William Whang, MD (william.whang@mountsinai.org)One Gustave Levy PlaceNew York, NY 10029212-241-7114We thank Dr. Wang for his interest in our research letter. He questions whether the endpoint used in our study, frequency of premature ventricular complexes (PVC) as a percentage of total complexes measured pre- versus post-ablation, is a valid indicator due to the skewed distribution and lack of granularity. Although we did not use absolute number of PVCs per day from a 24-hour Holter for our endpoint, we would argue that PVC percentage is a valid indicator of arrhythmia burden that has been associated in a dose-dependent manner with outcomes such as cardiomyopathy and mortality in cohorts such as the community-based Cardiovascular Health Study.1 In addition, in our study the median duration of monitoring (6 days) was longer than in prior studies of atrial fibrillation (AF) ablation and PVCs. A recent study that used commercially available event monitors concluded that longer monitoring periods resulted in significantly reduced mean measured error of PVC burden.2We sought to approach the measure for significant PVC burden (≥1000/day) mentioned by Dr. Wang, with a proxy threshold of ≥1% PVCs. In our sample 21.5% of patients had ≥1% PVCs pre-ablation and 19.2% had ≥1% PVCs post-ablation (p=0.76, chi-squared test), again suggesting lack of significant association between AF ablation and PVC burden. We agree with Dr. Wang that prospective studies would be worthwhile to assess the true impact of AF ablation on PVCs, and would stress that inclusion of samples unrestricted by PVC burden pre-ablation could help clarify this question.1. Dukes JW, Dewland TA, Vittinghoff E, Mandyam MC, Heckbert SR, Siscovick DS, Stein PK, Psaty BM, Sotoodehnia N, Gottdiener JS, Marcus GM. Ventricular Ectopy as a Predictor of Heart Failure and Death.Journal of the American College of Cardiology . 2015;66:101–109. 2. Krumerman A, Di Biase L, Gerstenfeld E, Dickfeld T, Verma N, Liberman L, Amara R, Kacorri A, Crosson L, Wilk A, Ferrick KJ. Premature ventricular complexes: Assessing burden density in a large national cohort to better define optimal ECG monitoring duration. Heart Rhythm . 2024;21:1289–1295.

Connor Oates

and 10 more

Background: Increasing interest in physiological pacing has been countered with challenges such as accurate lead deployment and increasing pacing thresholds with His-bundle pacing (HBP). More recently, left bundle branch area pacing (LBBAP) has emerged as an alternative approach to physiologic pacing. Objective: To compare procedural outcomes and pacing parameters at follow-up during initial adoption of HBP and LBBAP at a single center. Methods: Retrospective review, from September 2016 to January 2020, identified the first 50 patients each who underwent successful HBP or LBBAP. Pacing parameters were then assessed at first follow-up after implantation and after approximately one year, evaluating for acceptable pacing parameters defined as sensing R-wave amplitude >5 mV, threshold <2.5 V @ 0.5 ms and impedance between 400 and 1200 Ohms. Results: The HBP group was younger with lower ejection fraction compared to LBBP (73.2±15.3 vs 78.2±9.2 years, p=0.047; 51.0±15.9% vs 57.0±13.1%, p = 0.044). Post-procedural QRS widths were similarly narrow (119.8±21.2 vs. 116.7±15.2ms; p = 0.443) in both groups. Significantly fewer patients with HBP met the outcome for acceptable pacing parameters at initial follow-up (56.0% vs 96.4%, p = 0.001) and most recent follow-up (60.7% vs 94.9%, p = <0.001; at 399±259 vs. 228±124 days, p = <0.001). More HBP patients required lead revision due to early battery depletion (0 vs 13.3%, at an average of 664 days). Conclusion: During initial adoption, as compared with LBBAP, HBP is associated with a significantly higher frequency of unacceptable pacing parameters, energy consumption, and lead revisions.