A newborn with complete heart block and structural cardiac defects

Abstract

HISTORY OF PRESENT ILLNESS A 3,200-g girl was born to a 37-year-old human immunodeficiency virus–negative woman at 36 weeks’ gestation. The pregnancy was complicated by maternal type 2 diabetes mellitus (requiring insulin therapy during pregnancy) and by hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome.1 The baby was delivered by emergency cesarean section for maternal preeclampsia. Apgar scores were 8 at 1 minute of life and 9 at 5 minutes of life. Complex congenital heart disease had been diagnosed in utero by fetal ultrasound. The infant was promptly administered prostaglandin E2 shortly after birth and then was transferred to the neonatal intensive care unit. A chest radiograph (Fig 1) revealed a boot-shaped heart secondary to right ventricular hypertrophy and an abnormal main pulmonary artery segment. Also notable is the absence of a thymic shadow. Echocardiography revealed complete atrioventricular heart block, pulmonary atresia, and an unbalanced atrioventricular canal. Laboratory evaluation revealed a white blood cell count of 15,700/ L (reference range, 5,000–20,000/ L), a hemoglobin level of 17.3 g/dL (reference range, 13.5–20.5 g/dL), a platelet count of 151,000/ L (reference range, 140,000– 440,000/ L), an absolute lymphocyte count of 1,300/ L (reference range, 2,000–17,000/ L), and an absolute neutrophil count of 12,500/ L (reference range, 1,000–9,500/ L). Serum electrolyte values were normal except for a total calcium level of 7.5 mg/dL (reference range, 8.8–10.0 mg/ dL) and an ionized calcium level of 0.83 mmol/ L (reference range, 1.03–1.23 mmol/ L). The infant began peripheral hyperalimentation and underwent a Blalock-Taussig shunt and placement of an epicardial pacing system. Unifocalization of the pulmonary artery, a surgical technique to connect all pulmonary segments to convergent central pulmonary arteries, was performed on day 4 of life. It was confirmed at surgery that the thymus was absent. The infant began to have increasing calcium requirements, and at 1 week of age she was diagnosed as having hypoparathyroidism, with a parathyroid hormone level of 1 pg/mL (reference range,12–72 pg/mL).