Total anomalous pulmonary venous return

Background

• 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

Physiology

• 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 it 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

Clinical Features

• Varies with the degree of obstruction and the degree of left-to-right shunting.
• Respiratory distress and tachypnea
• Hypotension
• 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

Differential Diagnosis

Congenital Heart Disease Types

• Cyanotic
  • Tetralogy of fallot
  • Total anomalous pulmonary venous return
  • Transposition of the great arteries
  • Tricuspid atresia
  • Truncus arteriosus
  • Ebstein anomaly
  • Hypoplastic left heart syndrome
• Acyanotic
  • AV canal defect
  • Atrial septal defect (ASD)
  • Ventricular septal defect (VSD)
  • Cor triatriatum
  • Patent ductus arteriosus (PDA)
  • Pulmonary/aortic stenosis
  • Coarctation of the aorta
• Differentiation by pulmonary vascularity on CXR
  • Increased pulmonary vascularity
    • Large ASD
    • Large VSD
    • Total anomalous pulmonary venous return
    • Transposition of the great arteries
    • Truncus arteriosus
  • Decreased pulmonary vascularity
    • Tetralogy of fallot
    • Rare heart diseases with pulmonic stenosis

Evaluation

Snowman sign

• Echocardiography
• 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)
• ECG
  • May be normal
  • May have evidence of right ventricular hypertrophy or right atrial enlargement

Management

• 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

Disposition

• Admit

See Also

• Congenital heart disease