Objective. To investigate the effect of left ventricular diastolic dysfunction on the pathogenesis of angina decubitus （AD）. Methods. The study population consisted of three groups: 20 individuals without cardiovascular disease were studied as group Ⅰ.Group Ⅱ included 20 patents with coronary artery disease and without AD. Thirty-one patients with AD and ejection fraction（EF）>50% were studied as group Ⅲ. Group Ⅱ and Ⅲ were matched for age

EF and extent of coronary artery disease. Results. Left ventriculography （LVG） showed that left ventricular （LV） first 1/3 filling fraction（1/3FF） was significantly lower in group Ⅲ than in group Ⅱ and Ⅰ（both P<0001）

but LV late 1/3 FF was much higher in group Ⅲ than in group Ⅱ and Ⅰ（P<005

P<001）. Left ventricular end-diastolic pressure（LVEDP）was markedly increased before and after LVG in group Ⅱ and Ⅲ as compared with group Ⅰ （both P<005

both P<0001）. The difference of LVEDP caused by left atrial contraction （left atrial contraction pressure difference

LACPD）before and after LVG was much higher in group Ⅲ than in group Ⅰ （ P<001

P<0001）. Howevere

there were significant differences in LVEDP and in LACPD between before and after LVG only in group Ⅲ （both P<001）. Conclusion. The patients with AD have LV diastolic dysfunction

which may be closely related to the pathogenesis of angina decubitus.