Current Status of the Treatment of Complete Heart Block

Abstract

Medical management of complete heart block affords but a temporary control neither stable nor dependable and its failure is too frequently unheralded and fatal. Electric pacing by interim transvenous stimulation provides immediate, stable, and dependable control. Indications for transvenous pacing or pacemaker implantation should include not only Stokes-Adams disease, but heart block with signs and symptoms of diminished cardiac output and with heart rates under 40 per minute as well. Patients with complete heart block are protected best by pacing with a transvenous intracardiac dipolar electrode preparatory to and during anesthesia for surgery. A series of 40 patients is presented. There was a total of 56 catheterizations. There were nine emergencies requiring immediate transvenous pacing. In this group, there were five deaths due to extensive intercurrent disease. This stresses the importance of the use of the dipolar electrode in patients too ill for permanent implantation, because despite their desperate medical condition, four of these patients were supported sufficiently so that subsequent permanent implantation was done without a fatality. Permanent asynchronous implantable pacemakers, though requiring battery change, are relatively simple to insert and are preferable to externally worn units. Of the 31 patients who have had permanently implanted pacemakers, there was one postoperative death. The four others died months later of unrelated disease, and the remaining patients, despite corrective episodes of pacemaker failure are all well, free of symptoms of heart block, and rehabilitated to activity normal for their age. Those patients who returned because of permanent pacemaker system failure and were paced transvenously, and those patients with intermittent regular sinus rhythm exhibited competitive pacing mechanisms. Electric or sino-atrial impulses appearing during any phase of the cardiac cycle did not precipitate ventricular fibrillation.