Total Anomalous Venous Return
Occurs when all four pulmonary veins drain anomalously into the right heart.
1 - superior vena cava
2 - atrial septal defect
3 - left innominate vein
4 - pulmonary veins
Oxygenated blood returning from the lungs is routed back into the superior vena cava, rather than the left atrium. The presence of an atrial septal defect is necessary to allow partially oxygenated blood to reach the left side of the heart.
Cyanotic defect resulting in delivery of inadequately oxygenated blood.
Pulmonary veins have no connection to the left atrium. Left atrium is often small and non-compliant.
An atrial septal defect is considered part of the complex and is mandatory for survival.
All venous blood (oxygenated from pulmonary veins and unoxygenated from SVC/IVC) enters the right heart and exits the pulmonary artery. This creates pulmonary overcirculation and pulmonary hypertension.
Pulmonary veins may be obstructed and blood cannot exit the lungs.This creates a critical situation of low cardiac output from LV volume underloading, severe pulmonary congestion from the obstruction, hypoxemia and acidosis.
Obstructed veins have marked respiratory distress, cyanosis, dyspnea, tachycardia, and tachypnea.
Obstructed TAVR is difficult to differentiate from PPHN.
IV, O2, Monitor.
3cc/kg/hr D10W for infants under 1 year of age, D5W if over 1 year.
Treat CHF as needed, consider Lasix and Inotropic support.
Prostaglandins may make the situation worse in cyanotic obstructed veins by increasing pulmonary overcirculation.