Echocardiographic visualization of ventricular septal defect in infants and assessment of hemodynamic status using a contrast technique. Comparison of M-mode and two-dimensional imaging.

Twenty-seven patients with ventricular septal defect (VSD), ages 2 months to 2 years, were evaluated by both M-mode and two-dimensional echocardiography (2-D echo) with the aid of a peripheral venous contrast technique. M-mode echocardiography was unreliable for imaging VSD. Using 2-D echo, defects in the interventricular septum were visualized in all patients examined; defects in the membranous portion (24 patients) were visualized by the subcostal frontal approach and defects in the supracristal portion (three patients) by the subcostal sagittal approach. The 2-D echo contrast study revealed negative contrast jets appearing through the defect in the right ventricle in 22 patients with a pulmonary-to-systemic blood flow ratio greater than 2.0, and positive contrast jets appearing through the defect in the left ventricle in 13 patients with a right-to-left ventricular peak pressure ratio greater than 0.71. We conclude that 2-D echo with peripheral contrast technique confirmed the anatomic location of VSD and indicated the approximate right-to-left ventricular peak pressure ratio, showing the contrast material shunting through the defect itself.