Right Ventricular Volume Determinations in Children

Abstract

Right ventricular (RV) volumes were calculated from biplane cineangiocardiograms in 46 patients undergoing diagnostic cardiac catheterization. Validation of methodology was performed by comparison of known and calculated volumes of postmortem RV casts as well as by comparison of cineangiocardiographic RV and left ventricular (LV) stroke volumes of patients without shunts or valvular insufficiency. Seven infants, <1 year of age, with normal right hearts as compared with older children showed smaller RV end-diastolic volumes (39 ± 8 vs 70 ± 13 ml/m 2 , P < 0.001) as well as decreased RV systolic indices (SI) (3.71 ± 0.68 vs 4.66 ± 1.10 liters/min/m 2 , P < 0.05). There were no differences between normal infants and older children for RV ejection fraction (EF), RVEDV/LVEDV = 1.01, RVSI/LVSI = 0.99, and RVEF/LVEF = 1.04 vs 0.99. In 13 patients with isolated pulmonary stenosis, RVEDV, RVEF, RVSI, RVEDV/LVEDV, and RVSI/LVSI were not different from normal, but RVEF/LVEF averaged 1.13 vs 0.99 in normal infants, P < 0.05. In contrast, 11 patients studied with atrial septal defect or total anomalous pulmonary venous connection had significant increases in RVEDV (128 ml/m 2 ), RVSI (9.34 liters/min/m 2 ), RVEDV/LVEDV (2.36), RVSI/LVSI (2.81), and RVEF/LVEF (1.17), but normal values for RVEF. There was a significant linear relationship between Q p /Q s from oxygen data and RVSI/LVSI. In three patients studied an average of 1 year following atrial septal defect (ASD) repair, RVEDV remained elevated. In volume overload, alterations in RV volume characteristics are apparent and can be useful in shunt estimation; adaptation to an RV pressure overload, however, is not associated with detectable volume alterations.