A 4-month-old boy is brought to the pediatrician for a follow-up examination. He was born at 26 weeks’ gestation and spent the first 2 months of his life in ICU on oxygen and nutritional support. He is on home oxygen. Examination shows right-axis deviation and a loud P2. Chest x-ray shows increased vascular markings. Which of the following is the most likely explanation for these findings?
Bronchopulmonary dysplasia
Hyaline membrane disease
Lymphangioleiomyomatosis
Primary pulmonary hypertension
Transient tachypnea of the newborn
