Transmitral flow velocity profiles by Doppler echocardiography are strongly related to left ventricular diastolic properties. The aim of this study was to address the assessment of left ventricular filling pressures by transmitral flow velocity curves in patients with impaired systolic function. 90 patients (23 female, 67 men, age 60.0 +/- 9,9 a) with an ejection fraction < or = 45% either due to coronary artery disease (n = 67) or dilated cardiomyopathy (n = 23) were investigated by Doppler echocardiography prior to left heart catheterization. Early diastolic deceleration time (DT) and ratio of early to late diastolic peak velocities (VE/VA) were measured. Both, DT and VE/VA showed a significant correlation to left ventricular enddiastolic pressures (r = -0.79 respectively r = 0.73, p < 0.001 for all). According to DT three different transmitral flow patterns were identified. All patients with restrictive filling patterns (DT < 160) had elevated left ventricular filling pressures, whereas impaired relaxation (DT > 210) was a strong predictor of normal filling pressures. In patients with pseudonormal transmitral flow patterns (DT 160 to 210) filling pressures could not be predicted. Furthermore DT was strongly related to clinical signs of left heart failure. Doppler echocardiography gives useful additional information on left ventricular filling pressures in patients with systolic dysfunction.