We evaluated the treatment of left ventricular aneurysm (LVA) caused by myocardial infarction in 44 patients showing cineangiographical features of left ventricular aneurysm. Of the 44 patients, 28 were treated non-surgically (N-S) and 16 were treated surgically (S). Combined aortocoronary bypass graft (ACBG) with aneurysmectomy was performed on 10 patients. Clinical symptoms in LVA patients were angina (34%), congestive heart failure (31.8%), arrhythmia (29.5%), mitral regurgitation (9%), embolism (4%) and septal perforation (2.3%). Distribution of coronary arterial lesions were single vessel (isolated LAD) 29.5% and multiple vessel 59%. Parameters of LV performance measured at baseline in all LVA patients were: CI 3.05 +/- 0.64 L/min/m2, LVEDP 19.0 +/- 3.5 mmHg, LVEDV 200.6 +/- 25.9 ml, diast. wall stress 50.7 +/- 16.8 g/cm2, EF 0.46 +/- 0.15, LV dp/dt/p 17.8 +/- 2.1 S-1, SWI 61 +/- 24 gm/m2. LV performance after surgery showed clear decreases in LVEDP, LVEDV and wall stress (p less than 0.05, p less than 0.02 and p less than 0.02, respectively). In contrast, EF, LV dp/dt/p and SWI increased significantly (p less than 0.02, p less than 0.1 and p less than 0.01, respectively). Comparison of the results of restudy with first catheterization data in the N-S group showed decreases of EF, contractility index and LV dp/dt/p, each reaching p less than 0.1. Residual myocardial motion 1 year after the first cineangiographic study showed a significant decrease (-12.8 +/- 26.7%) in the N-S group, whereas in the S group it significantly increased to (+60.4 +/- 52.7%). A significant difference in coefficient of variation between N-S and S groups was found. Thus, it can be concluded that aneurysmectomy or concomitant myocardial revascularization with aneurysmectomy improves left ventricular diastolic performance and increases residual myocardial viability.