Echocardiographic ventricular shape analysis in congenital heart disease with right ventricular volume or pressure overload

In this 2-dimensional (2-D) echocardiographic study, a computerized Fourier analysis technique refined from one that allows quantification of changes in septal shapes in normal fetuses, newborns and infants allowed analysis of left ventricular (LV) shapes in 14 patients with right ventricular (RV) volume overload (atrial septal defects), 5 with volume and pressure overload (total anomalous pulmonary venous connection), and 10 with pressure overload (complete transposition of the great arteries [TGA] with intact ventricular septum). Diastolic shape factors in the 3 groups were significantly different from those of normal subjects (p <0.01). Highest diastolic values were found in patients with TGA (means 4.59 ± 1.28). Systolic shape factors were similar in patients with atrial septal defect and normal subjects. Significant differences existed between normal subjects and patients with total anomalous pulmonary venous connection, with the greatest differences in systolic shape factor being 5.61 for TGA vs 1.87 (p <0.005) for normal subjects. Shape factor correlated well with hemodynamic data for RV/LV systolic pressure ratios (r = 0.93, p <0.001) for normalized interventricular pressure differences (r = -0.95, p < 0.001). The lower the normalized systolic pressure difference or the higher the RV/LV ratio, the more the septum encroached into the LV cavity. Significant but weaker correlations were noted for values during diastole. Quantitative application of Fourier shape factor analysis to LV shapes allows numerical expression of visually interpreted distortions over a wide range of geometric alterations.