Evaluation of left ventricular size and function by echocardiography. Results in normal children.

Left ventricular (LV) size and function were studied by echocardiography in 145 normal children. The LV end-diastolic diameter (EDD) and its percentage change with systole (%deltaLVD) were measured and mean velocity of circumferential fiber shortening (Vcf) calculated. The LV pre-ejection period (PEP) and ejection time (LVET) were determined from recordings of aortic valve motion. The EDD increased by approximately threefold during childhood and was best correlated with the log of body weight (r = 0.95) and the log of body surface area (r = 0.96). The mean %deltaLVD was 36 +/- 4 (SD), and this index of LV function was independent of age and heart rate. Mean Vef was higher, and the absolute values of PEP and LVET shorter, in younger children with a faster heart rate. The mean ratio of PEP/LVET was 0.31 +/- 0.003, and was relatively independent of age (r = 0.41) and heart rate (r = 0.37). The %deltaLVD and PEP/LVET appear to be particularly useful indices of LV function because they remain constant during the course of childhood.