Diagnosis of atrial tumors by ultrasound.

A rapid, harmless, noninvasive technic using ultrasound to diagnose intra-atrial mass lesions is described. The technic permits detection of those tumors which pass through the atrioventricular orifice. Two patients with left atrial myxomata and one with a right atrial myxoma were studied with pulsed, reflected ultrasound, cardiac catheterization, and cineangiography. The diagnosis in each case was confirmed at surgery. The ultrasound technic for detecting atrial tumors was based on recording a mass of echoes immediately behind the echoes originating from the mitral or tricuspid valve leaflets. The mass held the leaflet open during diastole, causing abnormal valve motion. In one case of left atrial myxoma, the tumor plop sound, clinically confused with an opening snap, was shown to occur at a different time in the ultrasound cycle than the true opening snap. This examination is simple enough to be considered as a screening examination for the detection or exclusion of this rare but potentially dangerous abnormality.