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Key Features

Essentials of Diagnosis

  • Abnormal pulmonary venous connection leading to cyanosis

  • Occurs with or without a murmur and may have accentuated P2

  • Right atrial enlargement and right ventricular hypertrophy (RVH)

General Considerations

  • Accounts for 2% of all congenital heart lesions

  • Instead of the pulmonary veins draining into the left atrium, the veins empty into a confluence that usually is located behind the left atrium

  • However, the confluence is not connected to the left atrium and instead the pulmonary venous blood drains into the systemic venous system

  • Therefore, there is complete mixing of the systemic and pulmonary venous blood at the level of the right atrium

  • The presentation of a patient with total anomalous pulmonary venous return (TAPVR) depends on the route of drainage into the systemic circulation and whether or not this drainage route is obstructed

  • The malformation is classified as either intra-, supra-, or infracardiac

    • Intracardiac TAPVR occurs when the pulmonary venous confluence drains directly into the heart, usually via the coronary sinus into the right atrium (rarely direct drainage into the right atrium)

    • Supracardiac (or supradiaphragmatic) return is defined as a confluence that drains into the right superior vena cava, innominate vein, or persistent left superior vena cava

    • In infracardiac (or infradiaphragmatic) return, the confluence drains below the diaphragm usually into the portal venous system, which empties into the inferior vena cava

      • Infracardiac pulmonary venous return is very frequently obstructed

      • This lesion is a potential surgical emergency

      • Supracardiac veins may also be obstructed, though less commonly

  • Rarely, the pulmonary venous confluence drains to more than one location, called mixed TAPVR.

  • Because the entire venous drainage from the body returns to the right atrium, a right-to-left shunt must be present at the atrial level, either as an atrial septal defect (ASD) or a patent foramen ovale (PFO)

  • Occasionally, the atrial septum is restrictive and balloon septostomy is needed at birth to allow filling of the left heart

Clinical Findings

  • Mild cyanosis and tachypnea in the neonatal period and early infancy

  • Cardiomegaly and HF rather than cyanosis typically present in patients with unobstructed TAPVR and a large atrial communication high pulmonary blood flow

  • Examination discloses dusky nail beds and mucous membranes, but overt cyanosis and digital clubbing are usually absent

  • Oxygen saturations in the high 80s or low 90s are common

  • Mild to moderate elevation of pulmonary artery pressure owing to elevated pulmonary blood flow

  • An RV heave is palpable

  • P2 is increased

  • A systolic and diastolic murmur may be heard as a result of increased flow across the pulmonary and tricuspid valves, respectively



  • Chest radiography

    • Reveals cardiomegaly involving the right heart and pulmonary artery

    • Pulmonary vascular markings are increased

  • Echocardiography

    • Demonstration of a discrete chamber posterior to the left atrium and an ...

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