INDICATIONS FOR TREATMENT OF COMPLETE ATRIOVENTRICULAR DISSOCIATION.

FOR PURPOSES OF CORRECT TREATMENT IT IS IMPORTANT TO RECOGNIZE THAT PATIENTS WITH COMPLETE ATRIOVENTRICULAR DISSOCIATION FALL INTO THREE GROUPS: Group I-established third-degree heart block with and without Stokes-Adams attacks; Group II-periodic third-degree heart block with and without Stokes-Adams attacks; Group III-established third-degree heart block with cardiac failure. Most patients in Group I present no technical problems when a pacemaker is implanted. In Group II it is advisable to insert a temporary intracardiac catheter electrode and maintain a rate of 60 to 64 during the periods of third-degree heart block. Sudden reversion, in this group, from sinus rhythm can be fatal. Group III patients will often require a pacemaker set in excess of 74 beats until they are free of cardiac failure. Fifteen of 20 patients with complete atrioventricular dissociation showed marked functional improvement after insertion of a pacemaker. The development, in our laboratory, of a 4'' portable pacemaker impulse detector has been invaluable in locating the cause of failure in an implanted pacemaker.