A 3-day-old neonate on prostaglandin E1 (PGE1) infusion becomes dependent on ductal patency for systemic circulation. Echocardiography shows no flow across the aortic valve. Which lesion REQUIRES ductus-dependent SYSTEMIC circulation (not pulmonary) from PGE1?

• A Hypoplastic left heart syndrome (HLHS) ✓
• B Pulmonary atresia with intact ventricular septum
• C Tricuspid atresia with normally related great arteries
• D Total anomalous pulmonary venous connection (TAPVC)

Explanation

Hypoplastic left heart syndrome (HLHS) — characterized by aortic atresia, severe mitral hypoplasia, and severely underdeveloped left ventricle — has essentially no systemic (left-heart) circulation. Systemic blood flow entirely depends on right-to-left shunting across the ductus arteriosus to perfuse the systemic circulation (the aorta is supplied retrograde via the PDA). Closure of the ductus causes cardiovascular collapse and death. This is ductus-dependent SYSTEMIC circulation, contrasting with pulmonary atresia/tricuspid atresia where the ductus maintains ductus-dependent PULMONARY circulation. TAPVC does not require PGE1 unless obstructed with severe pulmonary hypertension.

Reference: Ghai Essential Pediatrics, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.