Early pacemaker lead thrombosis leading to massive pulmonary embolism.

Clinically apparent pulmonary embolism is a rare complication of permanent transvenous pacing catheters. Here we report an unusual case of a 71-year-old man who developed massive pulmonary embolism 12 hours after a permanent transvenous pacemaker implantation in the absence of any patient-related predisposing factor. Transesophageal echocardiography showed a large thrombus within the right atrium closely attached to the pacemaker lead. Anticoagulation with heparin, followed by warfarin therapy, led to a complete resolution of the thrombus.