A Neonate with Acute Heart Failure: Chromosomally Integrated Human Herpesvirus 6–Associated Dilated Cardiomyopathy

Abstract

A 4-day-old neonate was transferred to a tertiary heart center for further evaluation and management of sudden-onset acute heart failure (HF). The birth history was significant for being born at 37 weeks’ gestation to a 26-year-old mother with a probability 2 A0 blood type. There were no prenatal sonographic screenings of fetal cardiac status available. The mother had no history of smoking, diabetes, thyroid disease, autoimmune disorders, fever, or rash during pregnancy or before delivery. At birth, the patient’s Apgar scores were 8 and 8 at 1 and 5 minutes, respectively, weight was 3200 g (25th percentile), length 48 cm (10th percentile), and head circumference 36 cm (80th percentile). He developed respiratory distress on day 1 of life and was treated empirically to rule out sepsis. There was no history of fever, skin rash, nasal congestion, diarrhea, or sick contact noted. His respiratory status improved by day 2 of life, and he began oral feeding and otherwise progressed well until day 4 of life, when he was scheduled for discharge home but was noted to have a gallop rhythm. His echocardiogram showed a structurally normal heart but markedly dilated left ventricle (LV end-diastolic diameter was 3.24 cm (Z-score 6.7) with moderate mitral regurgitation and severely decreased systolic function, shortening fraction (SF) 11% (mean normal SF value is 36% with 95% predicted limits of 28% to 44%; Figure 1). When the patient arrived in cardiac intensive care unit, no dysmorphic features were noted on examination, his heart rate was 174 beats/min, he had delayed capillary refill (>5 seconds), diminished oxygenation (by near infrared spectroscopy), and had hypotension (systolic blood pressure in the range of 40-50 mm Hg). His S1 and S2 were normal, but a grade 1/6 systolic murmur at the left sternal border and gallop rhythm were noted. His lungs were clear to auscultation, but mild subcostal retractions were noted. The liver was palpable 3 cm below the right subcostal margin. The findings of his neurologic examination were normal, with normal muscle tone noted. He required resuscitation with inotropic support to achieve hemodynamic stability. Subsequently, a milrinone infusion was started for additional