INFLUENCE OF AGE, BODY SIZE AND HEART-RATE ON LEFT-VENTRICULAR DIASTOLIC INDEXES IN YOUNG SUBJECTS

Recently, a number of echocardiographic measurements have been proposed to assess diastolic function.1,2 Isovolumic relaxation time is closely correlated with early cardiac relaxation. Isovolumic relaxation time increases as relaxation becomes abnormal and with aging. Deceleration time provides a measure of the end of relaxation and the beginning of the diastolic compliance phase. Shortening of deceleration time occurs with restriction to ventricular filling. We selected these 2 measurements for study because both are easily obtained from a Doppler mitral tracing. However, some echocardiographic indexes of systolic function are known to be influenced by heart rate, body size or age, or a combination of all 3.3-5 Our purpose in this study was to determine if isovolumic relaxation time and deceleration time are age-, heart rate- or body size-dependent in a pediatrie and young adult group. © 1991.