Hypertrophic cardiomyopathy in a newborn infant

Abstract

the feet was appreciated. Bilateral hydroceles were noted. Results of neurologic examination were normal. A chest x-ray film showed marked cardiomegaly and normal pulmonary vascularity. Sinus tachycardia was apparent from the electrocardiogram with a heart rate of 160/min, QRS axis 120°. The PR interval was shortened to 0.08 seconds; there was severe biventricular hypertrophy with ST-T wave changes. The echocardiogram revealed severe left and right ventricular hypertrophy with compressed ventricular cavities (Fig 1). The left ventricular end-diastolic dimension was 18 mm (normal, 20 mm), and the end-systolic dimension was 6 mm (normal 13 mm). The left ventricular end-diastolic wall thickness was 12 mm (normal, 3.5 mm). The left ventricular shortening fraction was increased to 50%. There was anterior motion of the mitral valve during systole, and Doppler study showed mild subaortic obstruction. There was no aortic valve stenosis or coarctation of the aorta. Results of a skeletal survey were normal. Initial laboratory evaluation revealed: creatine kinase, 17.10 microkatal (μkat)/L (normal, 0.50 to 3.67 μkat/L [1026 U/L; normal, 30 to 220 /U/L]); serum total carnitine, 11 nmol/mL (normal, 17 to 46 nmol/mL); free carnitine, 8 nmol/mL (normal, 10 to 29 nmol/mL); urine catecholamines, 8 μg/24 h (normal, <540 μg/24 h). Results of urine hexuronic acid analysis (26 mg/g) were normal. Leukocyte lysosomal enzyme panel (including α-glucosidase CASE PRESENTATION Dr Chen