Abstract: To investigate the influences of preload,afterload and contractility of myocardium on left ventricular diastolic function,134 patients suffering from different kinds of diseases were examined by echocardiography.The patients were divided into five subgroups according to diameter of left atrium,end diastolic volume of left ventricle,mean arterial blood pressure, mean velocity of circumferential fiber shortening and ejection fraction of left ventricle.It was found that:①Variation of preload influenced chiefly early diastolic filling parameters,peak flow velocity of early diastole(EPFV)and time-velocity integral of early diastole (ETVI) which increased with increasing preload.②Variation of afterload influenced not only early, but also late diastolic filling parameters.ETVI increased,peak flow velocity of atrial contraction(APFV) and time-velocity integral of atrial contraction(ATVI) decreased,and the ratio between APFV and EPFV and between ATVI and total time-velocity integral (TTVI) re-duced with decreasing afterload.③Decreased contractility of myocardium as manifested by a reduction of EPFV and ETVI,and a significant componsatory increase in APFV,ATVI and the ratio between APFV and EPFV and between ATVI and TTVI in order to maintain the cardiac output.

Key words: echocardiography, Doppler, left ventricular diastolic function, preload, afterload, contractility of myocazdium