Complications in patients undergoing cardiac electrophysiologic procedures.

Complications were seen in 20 of 359 patients having programmed electrical stimulation during 1062 cardiac electrophysiologic procedures. No deaths occurred. Direct current countershock was used to end arrhythmias with serious hemodynamic consequences on 107 occasions. Countershock was effective in all cases and not associated with morbidity. The complications in 20 patients were related to intravascular catheterization and included thromboembolism (nine patients), local or systemic infections (six patients), and pneumothorax (five patients). All 20 patients recovered from these complications without long-term sequelae. Intracardiac electrophysiologic procedures can be done with an acceptably low risk in patients with life-threatening or disabling arrhythmias.