Cyanotic ostium secundum atrial septal defect without pulmonary hypertension and clinical signs of heart disease. Report of two cases.

In two cyanotic patients without clinical signs of cardiac disease, a contrast echocardiogram revealed a right-to-left shunt at the atrial level. In cardiac catheterization an atrial septal defect with bidirectional shunt was found, in spite of normal pulmonary pressures and vascular resistance. An anatomically atypical ostium secundum atrial septal defect was found at surgery. We emphasize the usability of the contrast echocardiogram in the investigation of a cyanotic patient, regardless of a lack of signs of cardiac disease in the clinical investigation.