Intracardiac short circuit.

In the past few years many centres have tended to prefer the pervenous to the transthoracic approach when implanting permanent pacemakers because of the reduced hospital stay and the lower postoperative morbidity. The disadvantages of this approach, however, are an increased failure rate and a greater incidence of late complications associated with the electrode. It may change in position and may fail to "capture" the ventricles. In addition perforation of the, catheter through the skin sometimes occurs, particularly with the neck approach. This latter complication was the first of a series of problems encountered in the patient described here.