Angiographic assessment of left ventricular volume, afterload and contractile state in normal children.

Left ventricular (LV) volume, mass and end-systolic stress were determined angiographically in 20 normal children aged 3 months to 16 years. LV contractile state was assessed by the analysis of the relation between end-systolic stress and ejection phase index or end-systolic volume. The LV volume and mass closely correlated with the body surface area. The LV mass/end-diastolic volume ratio (0.94 +/- 0.13 g/ml), ejection fraction (0.67 +/- 0.03) and circumferential end-systolic stress (163 +/- 21 kdynes/cm2, 165 +/- 21 g/cm2) remained constant despite the extensive increase in LV volume with physical growth. In all subjects significant inverse correlations were observed between end-systolic stress and ejection fraction or mean normalized systolic ejection rate. The ratio of the circumferential end-systolic stress to end-systolic volume index ranged from 5.00 to 12.57 (7.49 +/- 1.88). The ratio inversely correlated with age (r = -0.74, p less than 0.001), indicating that this ratio for estimating LV contractility is associated with ventricular size. These results suggested that the LV mass increased adequately in response to the extensive increase in LV cavity volume to maintain the end-systolic stress during growth in childhood and that physiologic cardiac growth was associated with appropriate hypertrophy with no significant change in LV contractile state.