Predictors of Right Ventricular Pacing in Patients Undergoing Implantable Defibrillator Placement

Introduction: Identifying patients who will develop a need for right ventricular (RV) pacing after defibrillator (ICD) placement would help inform appropriate device selection, specifically to identify patients who might be more suitable for dual chamber or biventricular transvenous defibrillators versus single-chamber or subcutaneous devices which do not provide pacing. We sought to determine predictors of RV pacing in patients who did not have a pacing indication at the time of initial ICD implant. Methods: This observational study assessed single-chamber ICD recipients implanted from 2006 to 2016 from Boston Scientific's ALTITUDE database and linked to the NCDR (R) ICD Registry. The study population (n = 11 044) of ICDs (programmed VVI mode at 40 bpm), and without a clinical indication for pacing. was randomly divided into training and validation cohorts (70/30) and characteristics associated with RV pacing were identified using logistic regression. The outcome was defined as the development of > 20% RV pacing averaged over any continuous 90-day period within 24 months after the ICD implant. Results: Patients who developed > 20% RV pacing (n = 148, 1.3%) had a higher likelihood of being older, male, and with a history of syncope, ventricular tachycardia or cardiac arrest, hypertension, previous or ongoing AF, and longer PR, QRS duration and BUN level (p < 0.01). After adjustment, PR > 230 ms, history of AF, ongoing AF at time of implant, history of VT or cardiac arrest, and age > 70 were independently associated with RV pacing. Conclusions: This study provides insight into predictors of RV pacing in ICD recipients without pacing needs at baseline.