Extracorporeal membrane oxygenation support in severe hypertrophic obstructive cardiomyopathy associated with persistent pulmonary hypertension in an infant of a diabetic mother.

A male infant was delivered at 37 weeks of gestation via cesarean delivery because of minimal fetal heart tone variability and late fetal decelerations to a 31-year-old mother whose pregnancy was complicated by maternal type 2 diabetes mellitus and chronic hypertension. Fetal echocardiography had been performed at 20 weeks of gestation , which showed a structurally normal heart without ventricular hypertrophy (Figure 1 and Movie IA and IB in the online-only Data Supplement). The mother had been treated previously with insulin, and during pregnancy, had hemoglobin A1c of 7.9% (diabetic patients with adequate glycemic control have values <7% to 8%). 1 The birth weight was 4.8 kilograms. The infant developed respiratory failure within the first 15 minutes of life, requiring intubation and mechanical ventilation. The umbilical cord venous blood gas demonstrated a pH of 7.16 and partial pressure of oxygen of 31 mm Hg. A transthoracic echocardiogram (TTE) was performed following the patient's admission to the neonatal intensive-care unit because of auscultation of a grade-IV/VI harsh systolic ejection murmur heard throughout the precor-dium. TTE showed severe biventricular hypertrophy, mild right ventricular outflow tract obstruction, severe left ven-tricular outflow tract obstruction with a peak velocity of 5.0 meters per second, almost complete obliteration of the left ventricular cavity, a patent foramen ovale with left-to-right shunting, a large patent ductus arteriosus (PDA) with bidi-rectional shunting, and rightward septal bowing throughout systole (Figure 2 and Movie IIA–IIC in the online-only Data Supplement). These findings were consistent with severe hypertrophic obstructive cardiomyopathy associated with infants of diabetic mothers (HOCM-IDM) and concomitant persistent pulmonary hypertension of the newborn (PPHN). HOCM-IDM is a well-recognized cardiomyopathy found in fetuses and infants at birth and is attributable to hyper-insulinism as a result of maternal gestational diabetes. It is characterized on echocardiogram by ventricular hypertrophy with greater septal hypertrophy than free-wall hypertrophy as well as resultant biventricular outflow tract obstruction. 2 It is classified as a hypertrophic cardiomyopathy and distinguished from other forms of hypertrophic cardiomyopa-thy by its transient and nonfamilial nature in the setting of hyperinsulinism. 3 The patient progressed with severe hypoxemia, requiring high conventional ventilatory support as well as circulatory failure indicated by hypotension responsive only to substantial fluid administration to maintain preload (requirement of >1.2 L of fluid in the first 24 hours of life). Medical management also included intravenous β-blockade for the dynamic outflow tract obstruction and inhaled nitric oxide for the PPHN. As …