Cyanotic congenital heart defects Quiz: Ace Your Exams

A 3-day-old newborn male is evaluated in the neonatal intensive care unit for breathing difficulty. The patient was born at 39 weeks gestation via vaginal delivery at home, and this is his first medical evaluation. The mother is a 26-year-old woman who had minimal prenatal care. She reports that he “was fine” after birth, but after the first few days, she noted a constant bluish color of his lips. Temperature is 37°C (98.6°F), pulse is 170/min, respirations are 65/min, and blood pressure is 80/50 mm Hg. Pulse oximetry shows an oxygen saturation of 84% on room air. Physical exam shows low-set ears and bulbous nasal tip. Cardiac auscultation reveals a loud, single second heart sound and bounding peripheral pulses. Chest radiograph shows pulmonary congestion with increased pulmonary markings and decreased soft-tissue attenuation in the right anterior mediastinum. Which of the following cardiac defects is most likely to be seen with further analysis of this patient?