Two-dimensional echocardiographic determinants of interventricular septal configurations in right or left ventricular overload.

Configurations of interventricular septum (IVS) and left ventricle were evaluated in 60 normal subjects and in 68 patients with congenital heart disease using two-dimensional short axis cross-sectional echocardiography (2DE). Patients were divided into four groups; right ventricular (RV) pressure overload (n = 21), RV volume overload (n = 12), left ventricular (LV) pressure overload (n = 10), and LV volume overload (n = 25). The radii of curvature of the IVS (IVSr) and LV free wall (FWr) were calculated in end systole and end diastole. Measured IVSr was normalized by dividing IVSr by FWr (IVSr/FWr). End-systolic flattening of IVS was a specific finding in patients with RV pressure overload, since this pattern was not observed in other hemodynamic groups. Echocardiographic determinants of IVSr/FWr in end systole correlated well with RV peak systolic pressure/LV peak systolic pressure ratio (r = 0.878). There was also correlation between IVSr/FWr in end diastole and RV end-diastolic pressure/LV end-diastolic pressure ratio (r = 0.579). Thus, the evaluation of IVS configuration is a useful 2DE method of estimating relative RV systolic pressure in infants and children with congenital heart disease.