A 50-year-old man with heart failure, systolic dysfunction, and abnormal septal motion underwent ventricular resynchronization. Postoperative clinical and echocardiographic improvement was observed. Several months later, he complained of worsening functional class after a traffic accident. Pacing lead fracture was diagnosed. After replacing the lead, improvement of clinical condition and ventricular parameters was achieved. The role of seat belts in causing dysfunction of pacemakers and resynchronization devices after deceleration injury is discussed.