Echocardiography in truncus arteriosus. The value of pulmonic valve detection.

Nine patients with a clinical presentation suggestive of truncus arteriosus were examined by echocardiography. Subsequent intracardiac studies including cardiac catheterization and angiocardiography divided this group into five patients with truncus arteriosus and four patients with other congenital heart diseases. In all patients with proven truncus arteriosus, it was possible to identify only one semilunar valve with a large truncal vessel overriding the ventricular septum. In none of these patients could a second semilunar valve be found. This study indicates that echocardiography may provide a direct, yet noninvasive method to exclude the diagnosis of truncus arteriosus by finding the pulmonic valve. However, the diagnosis of truncus arteriosus is not tenable when based solely on the inability to demonstrate the pulmonic valve. The importance of the clinical application of this method is discussed.