To determine the effect of recent advances in medical management on the survival of patients with dilated cardiomyopathy (DCM), 103 patients with DCM were studied. The subjects were divided into 3 groups based upon the time of initial medical treatment at our institute: Group I, between 1976 and 1981, 20 patients; Group II, between 1982 and 1985, 27 patients; and Group III, between 1986 and 1991, 56 patients. The clinical, Holter electrocardiographic and echocardiographic findings, the pharmacologic treatments used, and the clinical outcomes for the 3 groups of patients were compared. During the follow-up period, which averaged 27 months, 31 deaths related to cardiac disease occurred. The 4 year survival rate was 76% in Group III, 49% in Group II and 35% in Group I; the difference in survival rate between Groups I and III was significant (p < 0.01). At the initial evaluation, no differences were found among the 3 groups in the incidences of advanced heart failure (NYHA functional class III or IV), atrial fibrillation or complex ventricular arrhythmias. Neither diastolic blood pressure nor heart rate differed among the 3 groups, but Group III patients were older and had significantly higher systolic blood pressures than Group I patients (p < 0.05, for both comparisons). There were no differences among the 3 groups in % fractional shortening, left ventricular end-systolic wall stress or left ventricular wall thickness, but left ventricular dimensions were significantly smaller in Group III than in Group I (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)