ABSTRACT
Pacemaker Runaway is a rare, but potentially lethal complication after pacemaker implantation. Pacemaker runaway was one of the common manifestations of malfunctioning pacemaker at the time of fixed rate pacemaker, but has been less common after the demand type pacemaker had replaced the fixed rate model. The early recognition of runaway pacemaker is very important because runaway pacemaker can cause bradyarrhythmia, ventricular tachycardia-fibrillation and asystole resulting in syncope or death. We report a clinical experience of runaway pacemaker in 68 year-old woman, who received permanent pacemaker implantation(fixed rate 72/min, VVI, Micropulse 22U, Edwards system) due to sick sinus syndrome eight years ago. She complained of sudden chest tightness and dyspnea 10 days prior to admission. On physical examination, increased jugular venous pressure, rapid heart beats, basal rales on both lung fields and three finger-breath tender hepatomegaly. Electrocardiogram showed a rapid pacemaker rhythm of 140 beats per minute. So, the malfunctioning pacemaker was removed and replaced with a new programmable demand type pacemaker(VVI, OPTIMA-MP, Telectronics) in the same pocket under the diagnosis of pacemaker runaway. Her subject symptoms were relieved and electrocardiogram showed a regular pacemaker rhythm of 71 BPM. She was discharged ten days after pacemaker replacement.