Previous studies have demonstrated that in patients with various types of cardiac diseases and left ventricular dysfunction, left ventricular filling patterns assessed by Doppler of mitral flow are correlated to ventricular filling pressure, the prognostic value of which is well known. The current study was carried out to determine the prognostic importance of a noninvasive evaluation of left ventricular filling by Doppler of mitral flow in patients with systolic dysfunction after myocardial infarction and to compare its value with that of pulmonary wedge pressure. One hundred seven patients with a left ventricular ejection fraction < 40% were studied 3 to 12 weeks after myocardial infarction. All patients underwent a complete clinical examination, a standard two-dimensional and Doppler echocardiographic examination, and right-sided heart catheterization at rest and during a cardiopulmonary bicycle exercise test. Early and late diastolic peak flow velocities, their ratio, and the deceleration time of early diastolic velocity were measured from pulsed-wave Doppler of mitral flow. Follow-up data were obtained for 101 patients. During a mean period of 25 (median 21, range 12 to 60) months cardiac events (death, heart transplantation, or heart failure requiring hospitalization) occurred in 43 (42%) patients. Patients with cardiac events during follow-up were in a worse functional class and had a more impaired exercise capacity and higher capillary pulmonary wedge pressure at baseline examination. Among Doppler echocardiographic variables, in patients with cardiac events a greater early to late diastolic peak velocity ratio of mitral flow (1.9 +/- 0.9 pl/min vs 1.2 +/- 0.8 pl/min, p < 0.001) and a shorter early diastolic deceleration time (112 +/- 35 vs 145 +/- 42 msec, p < 0.001) were found. Cox analysis revealed that the combination of early to late diastolic peak flow velocity ratio of mitral flow and New York Heart Association functional class were the strongest noninvasive independent predictors of cardiac events. One-year event-free probability of survival was 90% in patients with an early to late diastolic peak velocity ratio < or = 1 (all but 1 in New York Heart Association functional class I or II) but was significantly less in patients with an early to late diastolic peak velocity ratio > 1 (64% in functional class I or II and 36% functional class III). Similar results were obtained when mean pulmonary wedge pressure was considered instead of the ratio between peak flow velocities of mitral flow.(ABSTRACT TRUNCATED AT 400 WORDS)