Loss of continuous biventricular pacing in cardiac resynchronization therapy patients: incidence, causes, and outcomes.

INTRODUCTION AND OBJECTIVES In recent years, implantation of cardiac resynchronization therapy devices has significantly increased. The benefits of this therapy are directly related to the maintenance of continuous biventricular pacing. This study analyzed the incidence, causes, and outcomes of loss of continuous biventricular pacing, and the approach adopted. METHODS We analyzed the clinical and follow-up data of a series of consecutive patients from a single center who underwent implantation of a cardiac resynchronization therapy device. RESULTS The study included 136 patients. During a mean follow-up of 33.4 months, loss of continuous biventricular pacing occurred in 45 patients (33%). The most common causes included atrial tachyarrhythmias (21.3%), lead macrodislodgement (18%), and loss of left ventricular capture (13.1%). In most patients (88.5%), loss of continuous biventricular pacing was transient and correctable, and occurred earlier in the follow-up when the cause was lead macrodislodgement, oversensing, or extracardiac stimulation. There were no significant differences in mortality between patients with and without loss of continuous biventricular pacing (P=.88). CONCLUSIONS Despite technical advances in cardiac resynchronization therapy, loss of continuous biventricular pacing is common; however, this loss can usually be corrected. In most patients, continuous biventricular pacing can be ensured by close monitoring and follow-up and a proactive approach.