To evaluate the influence of isometric exercise on left ventricular (LV) diastolic function, transmittal flow velocity was measured by pulsed Doppler echocardiography before and after handgrip in 15 normal subjects and the patients with hypertension as well as 18 patients with coronary heart disease (CHD). Statistically significant differences in peak velocity of early rapid filling (Ev), the ratios of peak early to late diastolic velocity (Ev/Av) and early to late velocity-time integral (Ei/Ai) between normal subjects and both the patients with hypertension and CHD were noted at rest. After isometric exercise, significant increase in Av (0.70 +/- 0.13 vs 0.76 +/- 0.14, P less than 0.01) and Ai/total VTi (0.35 +/- 0.07 vs 0.42 +/- 0.08, P less than 0.05) were showed in the hypertension group. In CHD, multiple Doppler parameters changed after isometric exercise with increase in Av (0.70 +/- 0.16 vs 0.85 +/- 0.18, P less than 0.01) and Ai/total VTi (0.36 +/- 0.08 vs 0.42 +/- 0.08, P less than 0.01) as well as decrease in Ev/Av (0.95 +/- 0.22 vs 0.82 +/- 0.15, P less than 0.05) and Ei/Ai (1.64 +/- 0.51 vs 1.35 +/- 0.34, P less than 0.05). However, there was no significant difference in any Doppler indices of LV diastolic function in the present normal subjects after isometric exercise. Thus, isometric exercise further enhanced late LV diastolic filling in the patients with impaired LV diastolic function in resting states greater than normal subjects, and myocardial ischemia induced by handgrip may play partial role in more changes in Doppler indices of LV diastolic function in CHD than the patients with hypertension.