To evaluate the hemodynamic changes that occur following radical left ventricular scar resection we studied 40 patients (mean age, 59.2 years; 36 males) with complete hemodynamic evaluation preoperatively (preop) and 5 to 12 days postoperatively (postop). Severe congestive heart failure (CHF) was present in 15 patients, ventricular arrhythmias in 19, and angina in 19 patients preop. The operation consisted of extensive scar resection with complete myocardial revascularization (average 2.4 grafts per patient). Ten patients required intraaortic balloon pump assist for up to 8 days postop. Postoperative left ventricular ejection fraction (EF) was estimated with multiple gated acquisition scanning. A significant rise in heart rate was observed in the whole group of patients postop (P = 0.000). In the group of patients with CHF preop the EF was increased from 25.1 +/- 8.4% (mean +/- SD) preop to 30.9 +/- 11.2% postop (P = 0.003), the cardiac index was increased from 2.2 +/- 0.5 liters/min/m2 preop to 2.7 +/- 0.5 liters/min/m2 postop (P = 0.02), and the pulmonary artery wedge pressure was decreased from 22.0 +/- 7.7 mm Hg preop to 15.5 +/- 4.3 mm Hg postop (P = 0.005). In the patients without active CHF preop no improvement in the above hemodynamics was noted. In conclusion, radical left ventricular scar resection significantly increased EF and CI and decreased PAW in patients with preop CHF, whereas in the absence of CHF this procedure resulted in minimal hemodynamic changes.