Acute Myocardial Infarction in Uncorrected Tetralogy of Fallot
A 22-year-old man presented with sudden severe substernal chest pain accompanied by dyspnea, nausea, and diaphoresis. There was a history of palliated Tetralogy of Fallot (TOF) with Blalock-Taussig (BT) shunt placement soon after birth, erythrocytosis with occasional need for phlebotomy, and hemoptysis. Prior angiography confirmed right ventricular outflow tract atresia, absence of the left pulmonary artery, and impaired left ventricular function. Clubbing and cyanosis, absence of right radial artery pulse, and continuous murmur over the right BT shunt were noted on physical examination. ECG demonstrated right axis deviation and acute ischemic current of injury in multiple leads (Figure 1). Laboratory evaluation showed an hematocrit of 59.2%.
One hour after onset of symptoms, angiography revealed normal coronary anatomy and a thrombotic occlusion of the mid left anterior descending artery (Figure 2A) without evidence of atherosclerosis. Primary percutaneous transluminal coronary angioplasty (PTCA) and stenting of the infarct-related artery was performed. Thrombolysis In Myocardial Infarction (TIMI) grade 2 flow was achieved despite adjunctive treatment with intracoronary tissue plasminogen activator (tPA), verapamil, nitroglycerin, and intravenous abciximab (Figure 2B). The patient was managed with an intraaortic balloon pump, anticoagulation, and low-dose β-blockers. Peak of creatine phosphokinase (CPK) was 6770 ng/mL. 2D-echocardiography demonstrated severe anteroapical hypokinesia, possible apical thrombus, large subaortic ventricular septal defect (VSD), and overriding aorta (Figure 3). The patient was asymptomatic after the procedure. He was discharged on the 8th day in stable condition.
Uncorrected TOF is rarely complicated by acute myocardial infarction. Although the case presented is likely secondary to thromboembolism, other potential etiologies with palliated TOF include anomalous coronary anatomy, erythrocytosis, and hyperviscosity syndrome.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
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