Myxoma of the Left Atrium

Abstract

Two patients with myxoma of the left atrium were studied by left heart catheterization and cineangiography, and the diagnosis was confirmed at operation in both cases. An electrocardiographic timing signal on the cineradiographs permitted correlation of heart sounds and pressure waves with movement of the tumor between the left atrium and the left ventricle. In early systole, the tumor suddenly moved from the left ventricle to the left atrium, and a notch in the rising left ventricular pressure, a prominent c wave, and loud, late elements of the first sound were noted. In early diastole, the tumor moved rapidly through the mitral valve, causing an abrupt diminution in the left atrial volume, thus causing a rapid y descent despite severe obstruction of the mitral valve. An early diastolic sound, thought to be an opening snap, appeared to be related to the checking of the tumor in the left ventricle ("tumor plop"). The unusual left atrial pressure pulse seen in these two cases resembles data from other cases of myxoma reported in the literature, and recognition of these unusual pressures may permit accurate preoperative diagnosis in other patients. Diagnostic changes may be present on apexcardiograms.