Summary:To confirm the feasibility and accuracy of the method for the noninvasive measurement of the left ventricular dp/dt, 53 patients with mitral regurgitation underwent simultaneous determination of left ventricular dp/dt by continuous-wave Doppler echocardiography and cardiac catheterization. Doppler-determined left ventricular dp/ dt is derived from the Doppler mitral regurgitant spectrum by dividing the magnitude of the left ventricular-atrial pressure gradient rise between 1 and 3 m / s of the mitral regurgitant velocity signal by the time taken for this change. Left ventricular dp/dt by Doppler ranged from 629 to 3494 mmHg/s (Tk SD, 1971 f 785 mmHg/s), and that by catheterization varied between 716 and 3650 mmHg/s (Tk SD, 1974 f 727 mmHg/s). There was a high correlation (r = 0.93, y = 0.862 x + 274.77, SEE = 271 mmHg/s, p