2.1
Congenital heart defects with a left‑to‑right shunt and excessive pulmonary blood flow can result in pulmonary hypertension and congestive heart failure in the neonatal period. The usual treatment is surgical correction of any defect when the infant is big enough. The most common defects needing this type of treatment include functionally univentricular hearts, transposition of the great arteries, and atrioventricular or multiple septal defects. The symptoms include fatigue, dyspnoea, tachypnoea and failure to thrive. Infants may develop a condition of irreversible pulmonary hypertension because of hypertrophy of the pulmonary arterioles.