title: Rate-dependent Loss of Capture during Ventricular Pacing.
abstract: A 63-year-old patient who had undergone atrial septal defect surgical repair received implantation of a single chamber VVI pacemaker for long RR intervals during atrial fibrillation. One week later, an intermittent loss of capture and sensing failure was detected at a pacing rate of 70 beats/min. However, a successful capture was observed during rapid pacing. Consequently, the pacing rate was temporarily adjusted to 90 beats/min. At the 3-month follow-up, the pacemaker was shown to be functioning properly independent of the pacing rate. An echocardiogram showed that the increased pacing rates were accompanied by a reduction in the right ventricular outflow tract dimension. The pacemaker was then permanently programmed at a lower rate of 60 beats/min.
authors.affiliation: Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, China.
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Wang
authors.forename: Haiyan
authors.initials: H
authors.lastname: Chen
authors.forename: Yangang
authors.initials: Y
authors.lastname: Su
authors.forename: Junbo
authors.initials: J
authors.lastname: Ge
mesh_terms: D001281:Atrial Fibrillation / Q000150:complications* / Q000628:therapy; D002304:Cardiac Pacing, Artificial / Q000379:methods; D004452:Echocardiography; D004868:Equipment Failure; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D013575:Syncope / Q000209:etiology* / Q000628:therapy; D016896:Treatment Outcome; D016278:Ventricular Function, Right