In agreement with classical data from the Institute of Pathology of the Armed Forces (Washington, DC), primary tumors of the heart, benign or malign, are found in 0.001% -0.28% of all of autopsies, and the myxomas represent 50% of the benign tumors of the heart 1 . Clinical experiences at two of the largest Brazilian institutions (InCor-USP and Dante Pazzanese Institute of Cardiology) demonstrate the wide prevalence of the heart myxomas as primary heart tumors. At InCor-USP, in a series of 50 patients treated over a period of 18 years, 84% of the myxomas were of the histological type 2 . At the Dante Pazzanese Institute of Cardiology, the experience was similar. Over a period of 28 years, with a series of 52 patients with heart tumors, 82.7% of the tumors were myxomas 3 . At the Ribeirão Preto Heart Hospital, over a period of 23 years, surgeons at the CECORP -Ribeirão Preto Specialized Heart and Lung Center operated on 7 patients for removal of heart tumors, 6 patients with myxomas and 1 patient with leiomyosarcoma metastasis. Among the 6 patients with heart myxomas, the age varied from 14 to 78 years, 4 were females, and all tumors were located at the left atrium. Although syncope is a symptom thoroughly described, resulting from myxoma left ventricular inflow obstruction, its incidence in the adolescent is rare, creating difficulties for the clinical evaluation of syncope in this age group. A unique case was reported in the literature of syncope as a consequence of left ventricle outflow obstruction, caused by a myxoma localized in this cardiac chamber 4 . A case of ischemic stroke in an 8-year-old female child has been reported in the Brazilian literature 5 . These data justify this case report of syncope in an adolescent caused by the presence of a left atrial heart myxoma that intermittently obstructed the mitral valve.
Case ReportA 14-year-old female, resident of São Simão (SP), had a clinical cardiology appointment in April 2000 because of 3 episodes of syncope over the previous 3 months. During this interval of time, she was evaluated by a neurologist, without any diagnostic conclusion about the syncope. She was then directed to the cardiologist due to the presence of palpitations experienced at rest.During the first cardiology consultation, a syncope diagnosis was the main focus of the investigation. The clinical anamnesis revealed palpitations, a heart rate of 130 bpm, and low corporal weight with accentuated loss in the prior 3 months. The heart auscultation, by this time, did not show evidence of a heart murmur. With the clinical hypothesis of hyperthyroidism, thyroid hormone dosages and an electrocardiogram were requested. The hormonal function was normal. The electrocardiogram identified a sinus tachycardia and a possible left atrium enlargement. The diagnostic