A 92-year-old small-framed man developed torsade de pointes during pacemaker-generator exchange. His family physician prescribed bepridil 200 mg/day. High bepridil concentration of 1409 ng/mL was revealed. Electrophysiologists at pacemaker clinic should pay attention to arrhythmia management including bepridil concentration when the family physician prescribes bepridil to a pacemaker patient.