To determine the effect of percutaneous transluminal coronary angioplasty on the left ventricular diastolic filling in patients with coronary artery disease, diastolic filling was serially examined before, early(within 2 days) and late(5~15 days) after PTCA using pulsed Doppler echocardiography in 14 patients(12 unstable angina; 2 stable angina). The Control group was consisted of 20 normal persons with similar age and sex distribution. The left anterior descending artery was dilated in 10 patients, the right coronary artery in 3 patients, and the circumflex artery in 1 patient. Peak velocity of early diastolic rapid inflow(E), peak velocity of late diastolic inflow (A), A/E ratio, and deceleration time of E wave were measured by pulsed Doppler echocar diography. 1) LVangiogram was performed in 10 patients, and showed normal wall motion in 7 cases and regional hypokinesia in 3 cases. Delta area decreasing rate was 59+/-10%, and LVEDP was 11+/-4 mmHg. 2) A/E ratio was greater in patient group(1.00+/-0.28) than in normal control (0.64+/-0.10) (p<0.05). There was no significant difference in A and E values between two groups. 3) A/E ratio decreased significantly from 1.00+/-0.28(pre-PTCA) to 0.85+/-0.24 (late post-PTCA) (p<0.01), but there was no significant change at early post-PTCA(0.94+/-0.32). Deceleration time also decreased significantly from 213+/-56 msec(pre-PTCA) to 177+/-34 msec (late post-PTCA) (p<0.05), but there was no significant change at early post-PTCA (199+/-34 msec). In conclusion, there was impairment of left ventricular diastolic filling in patients with coronary artery disease which gradually improved after PTCA, and this result probably is related to post-ischemic "stunned" myocardium.