To identify the predictive factors of left ventricular dysfunction (LVD) after surgery, we performed an uni- and multivariate analysis of the data concerning 286 patients operated for pure aortic regurgitation between 1980 and 1994 and 460 patients operated for pure non-ischemic mitral regurgitation over a period of 24 years. Among the aortic regurgitation patients, 28 developed left ventricular dysfunction not attributable to residual aortic valve dysfunction, another valvular lesion or hypertensive or ischemic heart disease. By univariate analysis identified predictive factors of LVD were duration of symptoms prior to surgery, duration of the history of diastolic murmur, NYHA class, cardiothoracic ratio, LV echographic diameters, fractional shortening of short axis, LV end-systolic volume and LV ejection fraction. Multivariate analysis identified three independent predictors: NYHA functional class, LV end-systolic diameter and LV ejection fraction. Of 428 operative survivors with non-ischemic mitral regurgitation 63 developed severe LVD. Univariate analysis identified functional class III or IV, duration of symptoms prior to surgery, atrial fibrillation, echo LV and LA diameters, angio LV volumes, LV ejection fraction, cardiac index and type of surgery as independent predictors of LVD. Multivariate analysis showed that type of surgery, LV ejection fraction, LV end-diastolic and end-systolic volume and echo LV end-systolic diameter were all independent predictors of LVD.