Total anomalous pulmonary venous return
- A cyanotic congenital heart defect
- All four pulmonary veins drain into the systemic venous circulation rather than into the left atrium.
- Four anatomic forms:
- Supracardiac (46%): pulmonary veins connect to the cardinal venous system (left innominate vein, superior vena cava, azygous vein)
- Cardiac (20%): pulmonary veins connect to the posterior aspect of the coronary sinus or directly to the right atrium
- Infracardiac (23%): Pulmonary veins drain into the portal vein, hepatic vein, or IVC
- Mixed (11%): Combination of connections that enter at 2 or more levels.
- Firth most common cause of cyanotic congenital heart disease 
- All oxygenated pulmonary venous blood mixes with deoxygenated blood from the systemic venous system
- Mixed/partially oxygenated blood then shunted right to left (through patent foramen ovale, PDA or an ASD), resulting in cyanosis
- The right atrium and ventricle become dilated because the right side of the heart receives blood from both pulmonary and systemic venous systems.
- In obstructed forms of TAPVR, the pulmonary venous system is compressed by surrounding structures
- May lead to RV hypertrophy and pulmonary vascular changes that may result in RV failure
- Varies with the degree of obstruction and the degree of left-to-right shunting.
- Respiratory distress and tachypnea
- Poor feeding, failure to thrive
- Fixed S2 split due to RV overload
- Systolic ejection murmur due to increased stroke volume across the pulmonary valve
- Hepatomegaly due to right-sided failure
- Variable degrees of cyanosis
Congenital Heart Disease Types
- Differentiation by pulmonary vascularity on CXR
- Angiography: gold standard but generally no longer required given other less invasive diagnostic modalities
- CT or MRA
- Chest x-ray
- Nonspecific findings, cannot be used to make diagnosis
- Prominence of pulmonary arteries
- Enlarged cardiac silhouette
- Classic snowman sign (for supracardiac TAPVC)
- May be normal
- May have evidence of right ventricular hypertrophy or right atrial enlargement
- Stabilize cardiopulmonary function prior to surgery
- Supplemental oxygen
- Mechanical ventilation
- Inotropic agents (eg, dopamine and dobutamine) improve myocardial contractility
- Diuretic therapy, (eg, furosemide) reduce preload, relieve volume overload and pulmonary congestion
- Prostaglandin E1 may be required to prevent closure of ductus arteriosus to maintain systemic cardiac output
- Primary surgical repair
- Reller MD. Prevalence of congenital heart defects in metropolitan Atlanta, 1998-2005. J Pediatr. 2008;153(6):807-13.
- Knipe K et al. Cyanotic congenital heart diseases. Radiopaedia. http://radiopaedia.org/articles/cyanotic-congenital-heart-disease