ABSTRACT
A 48-years-old woman with Lutembacher syndrome with a clinical and laboratory finding of atrial septal defect, of the ostium secundum type and without pulmonary hypertension was reported. We observed, from diagnostic viewpoint, that the electrocardiographic finding of left atrial overload and the echocardiographic pattern of mitral stenosis where the most important diagnostic sign the mitral valve involvement. The patient underwent surgery and the atrial septal defect was closed with a patch. After the surgery the signs of atrial septal defect where very poor and the signs of mitral stenosis dominated the clinical picture of the patient. Although we did not make any intervention at the mitral valve, the patient had a good outcome and until the present date she is in functional class I