Characterization of Left Heart Volumes and Mass in Normal Children and in Ifants with Intrinsic Myocardial Disease

Abstract

Quantitation of myocardial volumes, mass, and ejection fractions was performed in a group of 26 patients (10 of whom were infants less than 2 years old) with normal left ventricles and in a separate group of 13 children with intrinsic myocardial disease and clinical decompensation. All patients were studied by use of biplane cineangiocardiography, and volumes were determined by the area-length method. Left ventricular end-diastolic volume in "normal" infants below 2 years of age was 44.8 ± 8.5 cc/m 2 , and it was 71.4 ± 8.0 cc/m 2 in older normal children ( P <0.001), ages 3 to 16 years. Left ventricular ejection fraction also was different in the younger normals: 0.76 ± 0.07 versus 0.63 ± 0.05 in older normals ( P <0.001). Left ventricular mass and left atrial maximal volume were not significantly different in normal infants and older children, averaging 81.7 ± 10.0 g/m 2 and 33.6 ± 10.1 cc/m 2 , respectively. All patients in the cardiomyopathy group had significant elevations of left ventricular end-diastolic volume and mass, and the ejection fraction was reduced in all patients except one infant with severe mitral insufficiency. Five infants with chronic left ventricular failure and no mitral insufficiency had normal left atrial maximal volumes. Left atrial maximal volumes were increased significantly in six patients with myocardial disease, all of whom had mitral insufficiency. These results emphasize the potential value of the quantitative estimation of left heart volume and provide normative base-line data for left heart volume and mass parameters in both infants and children.