Right Ventricular Volume Determinations in Children

TLDR

Volume overload alters right‑ventricular volume characteristics useful for shunt estimation, whereas pressure overload does not produce detectable volume changes. Right‑ventricular volumes were derived from biplane cineangiocardiograms in 46 catheterization patients and validated against postmortem RV casts and matched RV/LV stroke volumes in patients without shunts or valvular insufficiency. Infants under one year exhibit smaller RV end‑diastolic volumes and lower systolic indices with unchanged ejection fraction; pulmonary stenosis shows normal RV volumes but higher RVEF/LVEF, while atrial septal defect or TAPVC causes marked RV volume and systolic index increases and elevated RVEF/LVEF ratios, with RVSI/LVSI correlating linearly with Qp/Qs and RVEDV remaining high one year after ASD repair.

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.