Formation and spontaneous closure of an arteriovenous fistula after transvenous pacemaker placement.

We report the findings in a patient with the unusual complication of arteriovenous fistula formation of the subclavian vessels seven weeks following placement of a dual-chamber pacemaker. The fistula's subsequent course was equally unusual, closing spontaneously three weeks later. It is postulated that the thrombotic and fibrotic reaction elicited by the leads contributed to the fistula's closure. Two surgical procedures, correction of the fistula and reimplantation of the pacemaker, were thus avoided by careful monitoring of the patient.