Angiocardiographic characteristics of the residual contracting left ventricle (LV) have been examined in 16 patients with anterolateral ventricular aneurysms (VA). In each patient a contractile section (CS) of the LV was clearly demarcated from the remaining aneurysmal section (AS). Using a double hemispheroid model, volumes of CS and AS were separately estimated by a modified area-length method. The volume of CS plus AS agreed closely with the volume of total LV estimated by the conventional area-length method. End-diastolic volume (EDV) of total LV ranged from 79 to 312ml/72. Aneurysmal section volume ranged from 8 to 264 ml/m2. End-diastolic volume of the contractile section ranged from 52 to 159 ml/m2 (mean, 100+/-8 (se); normal, 78+/-6). Contractile section ejection fraction (EF) showed a wide range, from 15% to 79% (mean 40%+/-17% SD). Nine patients underwent resection of VA. Three of six operated patients with CS EF less than 44% died; no survivor in this group has improved by more than one functional class (New York Heart Association classification). Three operated patients had CS EF greater than 45%; all survived and are improved, two having moved from class IV to class I. These data suggest that the EF of the contracting residual LV may be an important predictor of the outcome of resection of VA.