🩻 TOACS FCPS Station · Chest X‑ray in TAPVR
📷 Chest X‑ray (PA view)
🔍 Key radiographic features:
- ✓ Snowman or figure‑8 sign – supracardiac shadow
- ✓ Dilated left vertical vein + SVC form the 'snowman head'
- ✓ Mild to moderate cardiomegaly (right heart enlargement)
- ✓ Increased pulmonary vascularity (unobstructed type)
- ✓ Clear lung fields (no pulmonary edema)
📋 Clinical scenario (examiner prompt)
A 2‑month‑old infant presents with mild cyanosis, tachypnoea, and poor feeding. Oxygen saturation is 85% in room air. Cardiac auscultation reveals a systolic ejection murmur at the left upper sternal border and a fixed split S2. The chest X‑ray (PA view) shows a snowman or figure‑8 configuration of the cardiac silhouette.
🧑⚕️ Examiner tasks · TOACS
1. Identify the diagnosis from the X‑ray and clinical context.
2. Describe the pathology (pulmonary veins drain to systemic veins).
3. Describe the X‑ray findings (snowman sign, cardiomegaly).
4. Discuss classification (supracardiac, cardiac, infracardiac) and management.
🎯 Expected answers (for examiners)
- • Diagnosis: Total Anomalous Pulmonary Venous Return (TAPVR) – Supracardiac type
- • Pathology: All pulmonary veins drain to systemic veins; ASD required for survival
- • X‑ray: Snowman sign (dilated vertical vein + SVC), right heart enlargement
- • Types: Supracardiac (50%), Cardiac (25%), Infracardiac (20%, obstructed), Mixed
- • Management: Surgical repair – anastomose pulmonary veins to LA + close ASD
⚡ Quick FCPS‑style MCQ
The snowman sign on chest X‑ray in TAPVR is due to:
A. Dilated left ventricle and aorta B. Dilated vertical vein and SVC forming the supracardiac shadow C. Enlarged right atrium and ventricle D. Pericardial effusion📌 Topic summary ·
All pulmonary veins drain to systemic veins
Snowman sign (supracardiac), cardiomegaly
Supracardiac (50%), Cardiac (25%), Infracardiac (20%)
Infracardiac (90%), Supracardiac (40%)
Required for survival (mixing)
Anastomose PV confluence to LA + close ASD