Problems encountered during insertion of permanent endocardial pacing electrode.

Case reports of two potential problems arising during permanent endocardial pacemaker electrode insertion are described. They are cannulation of a persistent left-sided superior vena cava, and unsuspected subclavian vein thrombosis. A left-sided superior vena cava may be recognized clinically and avoided; but, if necessary, it can be employed as a route to the right ventricular endocardium. Subclavian vein thrombosis appears to be a complication of previous cephalic vein pacemaker insertion and prohibits further access on the implanted side. It may present with a painful, swollen arm or with the symptoms of multiple pulmonary emboli; occasionally it is not clinically suspected unless abnormal venous distension is sought.