A neonate is diagnosed with total anomalous pulmonary venous connection (TAPVC) with obstruction. Which of the following variants is MOST commonly associated with obstruction?

• A Supracardiac type (drainage to left innominate vein)
• B Cardiac type (drainage to coronary sinus)
• C Mixed type
• D Infracardiac type (drainage below diaphragm to portal vein) ✓

Explanation

In infracardiac TAPVC, the common pulmonary venous trunk descends through the diaphragm to drain into the portal vein, ductus venosus, or hepatic veins. The descending vein traverses the diaphragm through the esophageal hiatus or a separate opening, creating a functional obstruction point. The hepatic sinusoidal resistance further impedes venous return, producing severe pulmonary venous hypertension and pulmonary edema — presenting as a cyanotic neonate in respiratory distress with a 'snowman' or 'figure-8' sign absent on CXR.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.