Influence of Alteration in Preload on the Pattern of Left Ventricular Diastolic Filling as Assessed by Doppler Echocardiography in Huumans

was recorded simultaneously with pulsed Doppler echocardiography of left ventricular inflow and M-mode echocardiography of left ventricular diameter. Chamber stilfness constants, kd and k1, were obtained from the diastolic pressure-diameter and pressure-volume relations, respectively. Relaxation was measured by the isovolumic relaxation time constants, TL and TD, derived from the exponential left ventricular pressure decay and maximum negative dP/dt. In 41 patients after nitroglycerin treatment, left ventricular end-diastolic pressure decreased from 18±5 to 13±4 mm Hg (p<0.001). The ratio of peak early to peak atrial filling velocities and time-velocity integral ratios decreased from 1.08±0.57 to 0.90±0.42 (p<0.001) and from 1.77±0.95 to 1.41±0.71 (p<0.001), respectively. The peak early filling velocity and timevelocity integral decreased from 56.1±15.7 to 49.9±14.5 cm/sec (p<0.001) and from 7.9+2.7 to 6.8±2.8 cm (p <0.001), respectively. Relaxation (TL, TD, and maximum negative dP/dt) and chamber stiffness (kd and k) were not impaired after nitroglycerin administration. In 48 patients after ventriculography, left ventricular end-diastolic pressure increased from 18±6 to 22±8 mm Hg (p<0.001). The peak early and peak atrial filling velocities increased from 57.4±15.2 to 68.3±19.7 cm/sec (p<0.001) and from 61.0±22.7 to 69.4±23.2 cm/sec (p<0.01), respectively. As a result, the ratio of peak early to peak atrial filling velocity was unchanged. However, in the aortic stenosis group, the ratio of peak early to peak atrial filling velocity increased from 0.95±0.64 to 1.10±0.72 (p<0.02). Relaxation and chamber stiffness were unchanged. Thus, a reduction or increase in preload may induce a diastolic filling pattern that mimics or masks diastolic dysfunction, respectively. Preload conditions need to be accounted for when the status of diastolic function is extrapolated from the pulsed Doppler mitral inflow velocity profile. (Circulation 1989;79:1226-1236)