CAR-8. Persistent hypoxemia in a patient with right ventricular infarction.

Right ventricular infarction has many unique clinical features. Patients may present with hypotension, bradycardia, supraventricular arrhythmias, atypical EKG changes and hypoxemia. We present an unusual case of persistent hypoxemia in the setting of an acute right ventricular infarction. A robust 70-year-old white male presented to the ER with profound fatigue for 2 days. The patient was an avid outdoorsman who had been strenuously working at his mountain cabin when he suddenly became lightheaded, diaphoretic and nauseous with one episode of emesis and collapsed to the ground. After several hours of resting, he returned home 85 miles away. His daughter noted his poor appearance and brought him to the emergency department 2 days later. Preliminary evaluation revealed JVD 10 cm, ST elevation in leads II, III, aVF, troponin levels of 51.8, and a p[O.sub.2] of 45 on room air. A nuclear scan revealed no evidence of viable myocardium with a dilated, hypocontractile right ventricle. The patient was medically managed. His hypoxemia failed to correct with oxygen. An echocardiogram was obtained which revealed a large right to left shunt via a propatent foramen ovalis. The patient was referred for percutaneous closure. Hypoxemia and myocardial infarction are often encountered together by the general internist. This case presents a rare discovery of persistent hypoxemia caused by a shunt following a right ventricular infarction. We hypothesize that the infarction caused an acute increase in right-sided heart pressures causing a patent foramen ovalis to open creating a large right to left shunt with resultant hypoxemia. Interestingly, recent medical literature indicates that percutaneous atrial septostomy has been done for refractory cardiogenic shock due to ischemic right ventricular dysfunction. We present this case to promote early recognition of the symptoms and signs to ensure appropriate treatment of this often unrecognized syndrome.

Lindsay C. Crawford, MD, Mukta Panda, MD, and Suresh Enjeti MD. Department of Internal Medicine, University of Tennessee-Chattanooga Unit, Chattanooga, TN.