Venous anomalies of the coronary sinus: detection by M-mode, two-dimensional and contrast echocardiography.

The echocardiographic features of the enlarged coronary sinus are described in eight patients with a left superior vena cava draining to the coronary sinus and two patients with total anomalous pulmonary venous connection to the coronary sinus. The diagnosis was confirmed in each patient by cardiac catheterization and surgery. On the M-mode echocardiogram, a dense echo was present posterior to the mitral valve at the level of the atrioventricular junction. The clear space immediately behind this echo represented the enlarged coronary sinus. On the two-dimensional echocardiographic examination, the enlarged coronary sinus was seen in several planes; however, the structure was imaged best with the parasternal long-axis view. In the long-axis plane in the eight patients with a left superior vena cava, the coronary sinus was visualized as a distinct circular structure lying posteriorly in the atrioventricular junction. In the two patients with total anomalous pulmonary venous connection, the confluence of the pulmonary veins and its connection to the coronary sinus were imaged in the long-axis plane. These findings were substantiated by contrast M-mode and two-dimensional echocardiograms in five patients. The M-mode and two-dimensional echocardiographic examinations allowed detection of the enlarged coronary sinus and diagnosis of certain venous anomalies that caused increased coronary sinus blood flow. The two-dimensional echocardiographic examination easily distinguished the enlarged coronary sinus from other congenital lesions that cause anomalous echoes behind the anterior mitral valve leaflet on M-mode echocardiographic examination.