Makindo Medical Notes

💙 Total Anomalous Pulmonary Venous Drainage (TAPVD) is a rare cyanotic congenital heart defect. In TAPVD, all pulmonary veins drain into the right atrium (or systemic venous circulation) instead of the left atrium. Survival depends on an atrial septal defect (ASD) or patent foramen ovale to allow oxygenated blood to reach systemic circulation.

📌 About

• Extremely rare – about 1 in 20,000 births.
• Accounts for ~1–2% of congenital heart disease.
• Usually detected in the neonatal period rather than prenatally.

🧾 Aetiology

• Failure of normal connection of pulmonary veins to the left atrium during embryonic development.
• Instead, pulmonary venous return is to systemic venous circulation → complete mixing of oxygenated & deoxygenated blood.
• ASD/PFO is essential for systemic oxygen delivery and survival.

🔄 Types of TAPVD

• ☁️ Supracardiac: Pulmonary veins connect via a vertical vein to the superior vena cava (most common, ~50%).
• ⬇️ Infracardiac: Pulmonary veins drain to the inferior vena cava, often associated with obstruction (poor prognosis if untreated).
• ❤️ Cardiac: Pulmonary veins connect to the right atrium through the coronary sinus.
• 🔀 Mixed: Pulmonary veins drain to multiple abnormal sites.

🧑‍⚕️ Clinical Features

• 💙 Central cyanosis appearing soon after birth.
• 😮‍💨 Tachypnoea, respiratory distress.
• 🫀 Signs of heart failure: hepatomegaly, tachycardia, poor perfusion.
• 🍽️ Poor feeding and failure to thrive.
• 🔊 Murmurs: fixed split S2, systolic murmur from increased pulmonary flow.
• ❗ Obstructed TAPVD → severe cyanosis, pulmonary oedema, shock, early death if not corrected.

🔍 Investigations

• 🩻 CXR: Cardiomegaly; “snowman sign” in supracardiac TAPVD.
• 📈 ECG: Right ventricular hypertrophy.
• 🫀 Echocardiography: Diagnostic test of choice – shows anomalous venous drainage & ASD.
• 🧲 Cardiac MRI: Defines anatomy in complex cases.
• 🩺 Cardiac catheterisation: Rarely needed now, used if diagnosis unclear.

🧫 Pathology

• Complete right-to-left shunt of pulmonary venous blood.
• ASD/PFO acts as a “pressure relief” allowing some oxygenated blood to cross into systemic circulation.
• Chronic effects: pulmonary hypertension, right heart failure if untreated.

🛠️ Management

• ⚡ Stabilisation: Oxygen, diuretics, inotropes for heart failure.
• 💉 Prostaglandin E1 not helpful (ductus arteriosus does not improve circulation).
• 🔧 Surgery: Definitive treatment in the neonatal period:
  • Reconnect pulmonary venous confluence to left atrium.
  • Close ASD.
  • Ligate abnormal venous connections.
• 📅 Long-term outlook after surgery is excellent, with most children leading normal lives.

📚 References

• Royal Children’s Hospital – TAPVD