[Ostium secundum atrial septal defect: report of a case with atypical auscultatory findings (author's transl)].

The wide and persistent splitting of S2 is commonly considered the auscultatory hallmark of uncomplicated ostium secundum atrial septal defect (ASD). We have recently observed a 31-year-old female with a variable splitting of S2 and a 2/6 systolic murmur at the second left intercostal space, who showed incomplete right bundle branch block on the ECG and normal heart shadow with increased pulmonary vascular markings on the chest film. Cardiac catheterization revealed an isolated ostium secundum atrial septal defect with significant left-to-right shunt, normal pulmonary pressures and normal ventricular function. Subsequently the patient underwent closure with patch of the ASD without complications. We feel our case is of interest since it demonstrates that the absence of a wide and persistent splitting of S2 in adults does not exclude the diagnosis of uncomplicated "ostium secundum" ASD, when ECG and x-ray findings suggest the disease.