One hundred nineteen patients with drug-refractory ventricular tachycardia (VT) underwent mapping-guided subendocardial resection for control of their arrhythmias from 3 weeks to 10 years after acute myocardial infarction (AMI). Patients were separated into 2 groups: those treated early (within 4 months, group I) and those treated later (after 1 year, group II) after AMI. There were 32 patients in group I and 72 patients in group II. Both groups of patients had similar clinical, angiographic and hemodynamic characteristics. Patients in group I had VT with a shorter mean cycle length than patients in group II (322 +/- 71 vs 349 +/- 88 ms, p less than 0.05). The groups did not differ with respect to operative mortality (12% vs 7%), late mortality (31% vs 33%, mean follow-up 23 months), or frequency with which subendocardial resection without any adjunctive therapy prevented postoperative spontaneous or inducible VT (21% vs 34%). Group I was further separated into patients who underwent subendocardial resection within 1 month of AMI (n = 7) and those who underwent subendocardial resection with 2 months of AMI (n = 14). Although patients in group I were characterized by having more spontaneous morphologically distinct tachycardias, their operative mortality, total mortality and surgical success rates were comparable to those of patients in group II.(ABSTRACT TRUNCATED AT 250 WORDS)