Right ventricular contractile function in children with congenital heart disease

Indexes of right ventricular (RV) systolic function were evaluated in 41 patients undergoing cardiac catheterization. High-fidelity tracings were used to determine RV pressure, maximal RV dP/dt and the velocity of contractile element shortening at a developed pressure of 10 mm Hg (VCE10). In 14 children with an RV systolic pressure less than 35 mm Hg, normal RV volume, pulmonary vascular resistance (PVR) less than 3 units X m2 and no shunts (our normal group), mean (+/- standard deviation) RV dP/dt was 437 +/- 116 mm Hg X s-1 and VCE10 was 1.15 +/- 0.33 muscle length X s-1. In patients with RV systolic hypertension due to valvular pulmonary stenosis or isolated increases in PVR, mean values for RV dP/dt and VCE10 were significantly (p less than 0.05) greater than the normal values. In patients with a ventricular septal defect, RV hypertension and normal PVR, VCE10 was normal but RV dP/dt was significantly elevated. Children with chronic RV volume overload had normal RV contractile indexes. No patient in any group had values for RV dP/dt or VCE10 that were less than normal (mean normal - 2 standard deviations). This study establishes for the first time the indexes of RV isovolumic systole in children. It also shows that RV contractile function is preserved in young patients with chronic RV pressure or volume overload who do not have overt congestive heart failure.