Abstract

Background Frequent right ventricular (RV) pacing can lead to a decline in left ventricular ejection fraction (LVEF). Objective This study aimed to identify incidence and predictors of RV pacing-induced cardiomyopathy (PICM). Methods We retrospectively studied 1750 consecutive patients undergoing pacemaker implantation between 2003 and 2012. Patients were included if baseline LVEF was normal, single-chamber ventricular or dual-chamber pacemaker (but not implantable cardioverter-defibrillator or biventricular pacemaker) was implanted, frequent (≥20%) RV pacing was present, and repeat echocardiogram was available ≥1 year after implantation. PICM was defined as ≥10% decrease in LVEF, resulting in LVEF 115 ms was 90% specific for the development of PICM. Conclusion PICM may be more common than previously reported, and risk for its occurrence begins below the commonly accepted threshold of 40% pacing burden. Men with wider native QRS duration (particularly >115 ms) are at increased risk. These patients warrant closer follow-up with a lower threshold for biventricular pacing. Frequent right ventricular (RV) pacing can lead to a decline in left ventricular ejection fraction (LVEF). This study aimed to identify incidence and predictors of RV pacing-induced cardiomyopathy (PICM). We retrospectively studied 1750 consecutive patients undergoing pacemaker implantation between 2003 and 2012. Patients were included if baseline LVEF was normal, single-chamber ventricular or dual-chamber pacemaker (but not implantable cardioverter-defibrillator or biventricular pacemaker) was implanted, frequent (≥20%) RV pacing was present, and repeat echocardiogram was available ≥1 year after implantation. PICM was defined as ≥10% decrease in LVEF, resulting in LVEF 115 ms was 90% specific for the development of PICM. PICM may be more common than previously reported, and risk for its occurrence begins below the commonly accepted threshold of 40% pacing burden. Men with wider native QRS duration (particularly >115 ms) are at increased risk. These patients warrant closer follow-up with a lower threshold for biventricular pacing.