Bradycardia-Tachycardia Syndrome: Results in Twenty-eight Patients Treated by Combined Pharmacologic Therapy and Pacemaker Implantation

¹ Cardiac Unit, Department of Medicine, Harvard Medical School and Beth Israel Hospital, Boston

The bradycardia-tachycardia syndrome was treated with pacemaker implantation and drugs in 28 patients. All patients survived pacemaker implantation and 26 of 28 patients experienced good control of their arrhythmias. Nineteen patients survived for more than one year (group 1); nine patients survived for less than one year (group 2), including two patients whose arrhythmias were not well controlled by pacemaker plus drugs. There was no significant difference in mean age between the two groups (75 ± 5 years in group 1 and 79 ± 3 years in group 2). Gout, diabetes, hypertension, angina pectoris, and cardiomegaly were equally common in both groups. Prior to implantation, 14 of 19 patients in group 1 were in NYHA class 1-2; 8 of 9 patients in group 2 were in NYHA class 3-4. Generally, the clinical classification of cardiac status was not changed by treatment. Myocardial infarction, Ventricular tachycardia, and primary renal disease were distinctly more common in group 2. Massive myocardial infarctions, both old and recent, were found at necropsy. It is concluded that: (1) permanent pacemaker implantation, when combined with drug therapy, is effective in the control of the bradycardia-tachycardia syndrome; (2) the prognosis of patients successfully treated for the bradycardia-tachycardia syndrome is dependent on the extent of the underlying cardiac and renal disease.