The introduction of the implantable cardiac pacemaker has revolutionized the clinical management of heart block in the past three years.1Prior to this period, the treatment of the acute phase of Stokes-Adams syndrome and its long-term management was based on temporary artificial pacing of the heart and the use of drugs to improve atrioventricular (A-V) conduction and stimulate idioventricular pacemaker centers. At present, surgical implantation of an artificial pacemaker has become the standard procedure for the treatment of heart block. It therefore behooves the clinician to know the present indications for pacemaker implantation, the optimal time for surgery, the preoperative preparation, and the problems arising following pacemaker implantation. Recent experience has indicated that our present equipment, although superior to the original units introduced three years ago, is far from foolproof and that frequent mechanical and electrical breakdowns occur. This applies not only to the electrode wires, but also to