Increased heart rate caused by atrial pacing with the closed-loop stimulation function prevented micturition syncope

A 70-year-old man had been experiencing syncope several times a year. We implanted a DDD pacemaker with closed-loop stimulation (CLS) function. When he urinated early in the morning, his increased atrial pacing rates elevated his heart rate (HR) during and after micturition. After implantation of the DDD-CLS mode, he did not experience symptoms. In contrast, in the DDD-R mode, his intrinsic HR changed to atrial pacing after micturition but decreased to the basal rate within 2min, and he experienced a sense of cold perspiration and presyncope. Increased HRs caused by atrial pacing with the CLS function were useful in the prevention of micturition syncope.