A Hole in the Argument

This CLINICAL PROBLEM-SOLVING article describes an 80-year-old man who was evaluated of shortness of breath and fatigue four weeks after repair of a hiatal hernia. He reported a mild, nonproductive cough and abdominal bloating. Prior to the surgery, he had been very active and had had no dyspnea.
The patient had a history of coronary artery disease but no history suggested pulmonary disease.
He was found to have a substantial reduction in arterial oxygen saturation, with a a partial pressure of oxygen of 35 mm Hg. The findings on physical examination were unremarkable.
The normal cardiac examination and clear lung fields suggest that heart failure or significant pulmonary parenchymal disease is unlikely to explain his dyspnea. Pure oxygen was administered, but it did not improve his severe hypoxemia.
Transthoracic echocardiography was performed and videos of these may be reviewed at www.nejm.org.
This discussion by Donald Hegland highlights the challenge of determining the clinical significance of a common anomaly.