Refractory hypoxemia in right ventricular infarction: a case report.

Right ventricular infarction has many clinical features. Although hypoxemia is a common presenting symptom with multiple causes in the setting of myocardial infarction, the authors present a case resulting from an acute right-to-left shunt secondary to a previously dormant patent foramen ovale. A 74-year-old male presented to the hospital after feeling unwell for the previous 2 days. Initial evaluation revealed marked hypoxemia without respiratory distress. Electrocardiographic findings and cardiac seromarkers revealed a completed inferior myocardial infarction. The patient's hypoxemia was refractory to 100% oxygen, indicating a right-to-left shunt. A transesophageal echocardiogram confirmed clinical suspicions for a right-to-left shunt through a patent foramen ovale. Despite sporadic reports in the literature, this still is a poorly recognized clinical condition. The authors review a case report that will enable the general intemist to consider a right-to-left shunt in the setting of hypoxemia in myocardial infarction.