Echocardiographic Recognition of Mitral-Semilunar Valve Discontinuity

The angiographic recognition of mitral-semilunar valve discontinuity is a strong indication of origin of both great vessels from the right ventricle. This study shows that the same finding may be elicited by echocardiography, whether the great vessels are normally related or transposed. When mitral-semilunar valve continuity is present, the mitral valve echo at the onset of systole is continuous with and at the same depth as echoes from the posterior margin of the aorta (the great vessels being normally related) or from the pulmonary artery (the great vessels being transposed). In five case" where both great vessels originated from the right ventricle, echocardiography demonstrated mitral-semilunar valve discontinuity, with the posterior border of the adjacent great vessel lying anterior to the mitral valve echo. The degree of separation measured on the angiogram and by ultrasound was virtually identical. This atraumatic technique is a valuable adjunct to the evaluation of patients with complex congenital malformations, particularly when mitral-semilunar valve relationships are difficult to assess angiographically.