Paradoxical motion of the interventricular septum with right ventricular dilatation in the absence of shunting: report of two cases.

A history, heart murmur, electrocardiogram and chest X-ray film suggesting an atrial septal defect associated with an echocardiogram revealing paradoxical motion of the interventricular septum with a dilated right ventricle may be considered indicative of a secundum or primum defect in a young adult or child. Two patients who fulfill all these criteria and had the presumptive diagnosis of an atrial septal defect were found at cardiac catheterization to have no demonstrable left to right shunt or other significant abnormality. The results of standard T-M mode echocardiograms were verified with B scan ultrasonograms. These cases may represent an early stage in the development of a cardiomyopathy. There is no echocardiogram pathognomonic of an atrial septal defect, and patients whose history and echocardiogram suggest this defect should have further diagnostic evaluation including technetium scan or cardiac catheterization.