Visual diagnosis: chest pain in a boy with duchenne muscular dystrophy and cardiomyopathy.

Abstract

1. Philip T. Thrush, MD* 2. Kevin M. Flanigan, MD†,‡§ 3. Jerry R. Mendell, MD†,‡§ 4. Subha V. Raman, MD|| 5. Curt J. Daniels, MD*,|| 6. Hugh D. Allen, MD¶ 1. *Department of Pediatrics, The Ohio State University, The Heart Center, Nationwide Children's Hospital, Columbus, OH. 2. †The Center for Gene Therapy, Research Institute, Nationwide Children’s Hospital, Columbus, OH. 3. ‡Muscular Dystrophy Cooperative Research Center, Nationwide Children's Hospital, Columbus, OH. 4. §Departments of Pediatrics and Neurology, The Ohio State University, Nationwide Children's Hospital, Columbus, OH. 5. ||Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH. 6. ¶Associate Editor. Department of Pediatrics, Baylor College of Medicine, Texas Children’s Hospital, Houston, TX. * Abbreviations: DMD: : Duchenne muscular dystrophy EF: : ejection fraction ECG: : electrocardiography CMRI: : cardiac magnetic resonance imaging LGE: : late gadolinium enhancement A 17-year-old boy with Duchenne muscular dystrophy (DMD) due to a deletion of exons 18 to 37 in the DMD gene was diagnosed in our clinic as having cardiomyopathy at age 12 years. His current medications include deflazacort (30 mg/d), lisinopril (10 mg once daily for cardiomyopathy), and metoprolol succinate (50 mg twice daily for disordered automaticity). His cardiac function had been stable, with ejection fractions (EFs) ranging from 47% to 55%. After 1 day of headache and emesis, he presents to a local emergency department with acute onset of chest pain and shortness of breath. Electrocardiography (ECG) reveals ST-segment elevation in the inferolateral leads and ST-segment depression in the midprecordial leads, which prompts further testing (Figure 1). His initial troponin I level is elevated. He is transferred to a tertiary care facility for further evaluation. At the time of admission, his chest pain is substantially improved without intervention, but his troponin I level is now 40.27 ng/mL (40.27 μg/L) (reference range, <0.04 ng/mL [<0.04 μg/L]). Further laboratory evaluation reveals a white blood cell count of 12,900 /μL, 72% neutrophils, 20% lymphocytes, a C-reactive protein level of 299.8 mg/L (2855.3 nmol/L) (reference range, <12.0 mg/L [114.3 nmol/L]), and a lactate level of 7.2 mg/dL (0.8 mmol/L) (reference range, 4.5-19.8 mg/dL [0.5-2.2 mmol/L]). Cardiac magnetic resonance imaging (CMRI) with late gadolinium enhancement (LGE) reveals extensive left ventricular lateral wall epicardial enhancement (Figure 2A) and an EF of 50%. Quantitative T2 mapping reveals an increased T2 signal (80 milliseconds compared with 48 milliseconds in the unaffected interventricular septum) in the same region consistent with acute inflammation and injury …