Evaluation by Doppler Echocardiography of Transmitral Flow Disturbance in Patients with Left Atrial Myxoma

Abstract

The present study evaluated the characteristics of the transmitral flow disturbance caused by left atrial (LA) myxomas using Doppler echocardiography and correlated the findings with clinical, hemodynamic and imaging presentations. In the course of the evaluation of 14 patients with LA myxomas, the transmitral flow velocity profile during diastole was divided into three definitive types. Type A; High transmitral flow velocity of short duration in early diastole and almost no transmitral flow in mid to late diastole after prolapse of the myxoma. This finding originated from myxomas which were large and prolapsing in nature. Type B: Continuous interruption of transmitral flow throughout diastole. This type consisted of middle-sized and prolapsing myxomas. Type C: No disturbance of transmitral flow. This finding was observed in patients with nonprolapsing middle-sized myxomas or small prolapsing tumors. Symptoms of heart failure and pulmonary hypertension were present in types A and B, but not in type C. Embolization was observed in 3 of 6 patients in type C. These findings suggest that the severity of transmitral flow obstruction produced by LA myxomas may have a wide range, depending on the size, position and presence or absence of prolapse. Mitral regurgitation was seen in many of our patients’ Doppler examinations (64%), but it disappeared in all cases after simple excision of the tumor. We conclude that Doppler echocardiography can provide information about the hemodynamic alterations caused by LA myxomas and help us to understand the wide range of clinical manifestations of this entity.