RESUMO
The experience at the National Institute of Cardiology with atrial myxoma from 1944 to 1980 is presented; twelve patients were diagnosed, 8 females and 4 males, their age varied from 14 to 66 years. The tumor was inside the left atrium (LA) in 10 patients and in the right atrium (RA) in two. The diagnosis was confirmed by surgery or postmortem study. The symptoms and physical examination simulated mitral stenosis in the cases with myxoma of the LA, and pulmonary stenosis and Ebstein's anomaly in the two cases with RA myxoma. Symptoms of atrioventricular occlusion or embolic accident occurred by 5 patients and 3 of them died. The tumor was a postmortem discovery in the first cases, the next ones were an operatory surprise and the last ones were diagnosed by echocardiography. The advent of this technic has been definitive, all 7 patients studied by this method were diagnosed; in one the catheterism was interpreted as mitral stenosis and in other, during this procedure, cardiac arrest developed. The surgical removal of the tumor was successful in the nine patients that were operated. A correct and early diagnosis as well as an urgent surgical approach are necessary. With echocardiographic demonstration of the tumor, one patient died while he was waiting for surgical treatment.