Atrial rate-responsive pacing (RRP) has proved to be safe in pacemaker recipients with chronotropic incompetence. Although RRP is available in all current implantable cardioverter defibrillators (ICDs), the outcomes of this pacing mode in ICD patients are unknown. The aim is to evaluate the relationship between atrial RRP and atrial arrhythmias in ICD recipients.Methods:
Dual-chamber and triple-chamber ICD patients were included in this multicenter cohort study. Patients with permanent atrial fibrillation (AF) or VVI pacing mode were excluded. The number and duration of atrial tachycardia (AT)/AF episodes were assessed.Results:
Data from 415 patients and 80,707 AT/AF episodes (median duration: 0.4 hours) were collected after a 21.3 ± 14.1-month follow-up. Atrial RRP was programmed in 90 (21.7%) patients and was associated with a higher atrial pacing percentage in the overall study population (51.2 ± 33.8% vs 18.4 ± 25.7%, P < 0.001) and to a higher ventricular pacing percentage among dual-chamber devices (22.3 ± 37.6% vs 9.3 ± 25%, P < 0.001). Independent factors associated with sustained AT/AF episodes (>23 hours) were previous AF (odds ratio [OR]: 7.98; 95% confidence interval [CI]: 4.11–15.47; P < 0.001) and atrial RRP (OR: 3.58; 95% CI: 1.82–7.03; P < 0.001). RRP was related to a lower sustained AT/AF episodes-free survival both in patients with a history of AF (43% vs 70%, P = 0.035) and without a history of AF (82% vs 97%, P = 0.004) at 2 years.Conclusions:
Atrial RRP in ICD patients was related to a higher incidence of sustained atrial arrhythmias. This pacing mode may have an atrial proarrhythmic effect on ICD patients, especially among those with a history of AF.