Contractile function in patients with ischemic left ventricular (LV) dysfunction may improve after myocardial revascularization. Currently, the incidence of contractile function recovery after revascularization in these patients is unclear. The aim of this study was to assess the incidence of function improvement after myocardial revascularization in patients with ischemic LV dysfunction. A total of 258 consecutive patients (aged 59 +/- 12 years) with severely depressed LV ejection fractions (EFs) due to chronic coronary artery disease and heart failure symptoms were studied. All patients underwent radionuclide ventriculography and 2-dimensional echocardiography at rest before and 3 to 6 months after revascularization. At baseline, 1,330 segments (32%) were normal and 2,775 segments (68%) were dysfunctional. Improvement after revascularization occurred in 736 of the 2,775 dysfunctional segments (27%). Overall, LVEF improved from 29 +/- 7 to 32 +/- 9 (p <0.0001). A clinically significant improvement of LVEF (>/=5% postrevascularization) was present in 101 patients (39%). Improvement of LVEF after revascularization was frequently observed in patients with a more severely impaired baseline LVEF. At least 3 segments with improvement of function were needed for an improvement of LVEF of >/=5%.