The pulsed wave Doppler echocardiography in the mitral inflow is used widely for the assessment of LV diastolic function. The echocardiographic index of LV diastolic function is known to be affected by several factors, such as the loading condition. In the Doppler tissue image (DTI), the mitral annulus velocity is known to be unaffected by the loading condition. The purpose of this study was to investigate the effect of the preload reduction on the mitral annulus velocity.

We examined the transmitral and pulmonary venous flows, and the mitral annulus velocity in 30 patients with chronic renal failure, but a normal LV systolic function, by echocardiography, both before and after hemodialysis. The study patients were divided into two groups; Group I (preload reduction < or = 2.0 kg, N=10) and Group II (preload reduction>2.0 kg, N=20).

In the transmitral flow; the E velocity was changed, both before and after hemodialysis, in Group II. < Group I from 97±12 cm/s to 86±11 cm/s (NS), Group II from 85±5 cm/s to 63±5 cm/s (p=0.0001)<. The A velocity was also changed in Group II. In the mitral septal annulus velocity by DTI; The E' velocity was changed in both groups, but the A' velocity was only changed in Group II. In the mitral lateral annulus velocity by DTI; all indices remained unchanged in both groups.

These results suggested that a vigorous preload reduction might change the echocardiographic indices, and either the transmitral flow pattern or the mitral septal annulus velocity. The mitral lateral annulus velocity indices, which are useful for the evaluation of the LV diastolic function, were unchanged by the preload reduction. The preload condition needs to be accounted for when evaluating the LV diastolic function with a Doppler echocardiography.