Atrioventricular membrane perforation: a very rare complication of transvenous pacemaker implantation.

A 63-year-old man was admitted to our emergency department with the complaint of syncope. An electrocardiogram showed complete atrioventricular block with a low ventricular rate. He was hospitalized and a temporary transfemoral pacemaker was inserted under direct fluoroscopy urgently. Immediate postprocedural electrocardiogram in the paced mode showed right bundle branch block morphology that led to suggestion of abnormal lead location. A transthoracic echocardiogram revealed that the pacemaker lead was directly inserted from the right atrium into the left ventricle through the junction of the interatrial and interventricular septums. Because severe multivessel coronary artery disease was diagnosed angiographically in his subsequent hospital course, coronary artery bypass grafting and surgical extraction of the misplaced lead was performed at the same time. Clinical implications, diagnosis, and therapeutic options of left ventricular pacemaker lead malposition are discussed.