We report the case of a rescued 84-year-old patient with atrial septal defect (ASD) who was emergently admitted to our intensive care unit with progressive dyspnea requiring mechanical ventilation for severe anoxia and respiratory arrest. She had no history of congenital heart diseases. EGG and chest X-ray revealed overload of the right atrium and ventricle, and severe increase in pulmonary vascular markings. Transesophageal echocardiography showed a moderately large size ASD (18 x 23 mm(2)). Hemodynamic evaluation documented an increase in PA pressure of 37/16 mm Hg and Q(p)/Q(s) of 2.33. Her systemic condition did not improve following diuretics, cathecholamine, and afterload-reducing substances. She required mechanical ventilation for severe hypoxia. She underwent successful closure of the ASD using an Amplatzer septal occluder on day 17. Hemodynamics and findings on chest X-ray dramatically improved after this procedure. She was discharged from the hospital on foot. (C) 2006 Wiley-Liss, Inc.