Background: Right ventricular pacing (RVP) increases heart failure, AF, and death rates in pacemaker patients and ventricular arrhythmias (VAs) in defibrillator patients. However, the impact of RVP on VAs burden and its clinical significance in pacemaker patients with normal range LVEF of > 50–55% remains unknown. We sought to evaluate the relationship of RVP and VAs and its clinical impact in a pacemaker patient population. Methods: Records of 105 patients who underwent de novo dual-chamber pacemaker implant or a generator change (Medtronic™ or Boston Scientific™) for AV block and sinus node disease at a tertiary care center between September 1, 2015, and September 1, 2016, were retrospectively reviewed. Results: Data from 105 patients (51% females, mean age 76 ± 1 years, mean LVEF 61 ± 0.7%) without history of VAs (98.2%) were reviewed over 1044 ± 23 days. Dependent patients (100% RVP) exhibited the lowest VAs burden when compared to < 100% RVP (isolated PVCs, PVC runs of < 4 beats, and NSVT; p ≤ 0.001). Patients with < 1% RVP also exhibited low VA burden with intermediate RVP (1–99.9%) being most arrhythmogenic for PVC runs (p = 0.04) and for isolated PVCs (p = 0.006). Antiarrhythmics/beta and calcium channel blockers use and stress tests performed to evaluate VAs which were positive requiring intervention did not differ significantly. Burden of > 1/h of PVC runs and increasing PVC runs/h were significantly associated with hospitalization (p = 0.04) and all-cause mortality (p = 0.03), respectively. Conclusions In pacemaker patients with normal range LVEF (> 50–55%), 100% RVP is associated with the lowest burden of NSVT. Furthermore, patients with < 1% RVP also exhibit low VA burden; however, intermittent RVP seems to significantly correlate with non-sustained VAs.

Background: Reactive atrial-based anti-tachycardia pacing (rATP) in CIED (cardiovascular implantable electronic devices) is effective in atrial fibrillation (AF) suppression. Uninterrupted systemic anticoagulation is recommended when this algorithm is activated to avoid stroke, however, the use of a rATP algorithm in patients with a left atrial appendage (LAA) closure device has not been studied. We assessed the safety and feasibility of rATP algorithm to sup‑ press AF in patients with a LAA closure device over an extended period. Methods: Data from 55 consecutive patients who underwent a ­Watchman® implant at a tertiary care hospital between September 1, 2015, and January 30, 2020, who also had an in situ ­Medtronic® CIED (45 with and 10 with‑ out rATP capability) were retrospectively reviewed. Results: The 55-patient cohort was 60% male, 77 ± 8 years old, ­CHA2DS2 -VASc score 5 (4–6), HAS-BLED score 3 (3–4), LVEF 53 ± 14%, LA size 4.4 ± 0.7 cm and ventricular pacing burden of 73 (1.4–98.3)%. The CIEDs (20 ICDs and 35 pace‑ makers) antedated ­Watchman® implants by 915 ± 725 days. Post-implant, all patients discontinued anticoagulation.Twenty patients in the rhythm-control group with active rATP algorithm displayed no increase in yearly AF burden and were less likely to develop permanent/long-standing persistent AF (p = 0.002) when compared to 35 patients in the rate-control group with CIEDs inactive/incapable of rATP over a ≤ 5-year follow-up. The longest AF episode in the rhythm-control group lasted 204 (19–2520) h. There was no increase in stroke/thromboembolism and a significant reduction in major bleeding noted over ≤ 5 years pre- versus post-implant in the whole cohort (p = 0.005). Conclusion rATP algorithm use is safe and feasible in patients with a ­Watchman® device. Patients should be fore‑ warned of a surge in post-Watchman® implant AF burden.