Total anomalous pulmonary venous connection pathophysiology

Pathophysiology

In patients of Total anomalous pulmonary venous connection (TAPVC)there is a mixing of oxygenated pulmonary venous blood with deoxygenated blood from systemic circulation

It mixing of blood could occur at three levels i.e. supracardiac, infracardiac and cardiac. In the former two the mixing occurs outside the heart and in latter inside the heart (right atrium).

This mixed deoxygenated blood is shunted from right-to-left side of heart(patent foramen ovale, atrial septal defect or patent ductus arteriosus). This right to left shunting causes cyanosis in the patient.

Since, the right side of heart is receiving blood both from pulmonary and systemic circulation it leads to development of pulmonary hypertension, right atrial and ventricular hypertrophy. Level of obstructions seen are-

• Supracardiac
• Infracardiac
• Cardiac
• Other — Other sources of obstruction include stenotic, tortuous or atretic pulmonary .

Unobstructed forms — No significant stenosis of the pulmonary veins