Two-dimensional echocardiography in the diagnosis of left atrial myxoma.

We performed M-mode echocardiograms on 11 patients who later had left atrial myxomas removed at operations. Seven of these 11 patients were also examined with two-dimensional echocardiography. M-mode echocardiography showed the characteristic pattern of a left atrial mass entering the mitral orifice during diastole in nine of the 11 patients. M-mode echocardiographic findings were equivocal in two patients because a short tumour stalk prevented significant motion of the tumour. Cross-sectional echocardiography clearly showed a left atrial mass attached by a stalk to the interatrial septum in all seven patients examined, including one patient in whom the tumour was immobile. Three-dimensional measurements of tumour size made from orthogonal cross-sectional echocardiographic planes were within 6 mm of similar measurements made on the excised tumours.