Introduction
- Total Anomalous Pulmonary Venous Connection (TAPVC) or Return (TAPVR) is a rare congenital cyanotic heart defect where the four pulmonary veins do not drain into the left atrium but via unique pathways into the right atrium or systemic veins.
- Must have atrial septal defect or patent foramen ovale to be compatible with life and permit mixing of oxygenated blood.
https://en.wikipedia.org/wiki/Anomalous_pulmonary_venous_connection
Variants from most to least common:
Click HERE to watch a video link showing the structural anomalies of the three most common variants:
- Supracardiac (43%)
- Anomalous vein returning pulmonary venous blood from the lungs to the superior vena cava.
- Confluence of pulmonary veins behind, but not connected to the left atrium.
- Atrial septal defect allows blood flow to left atrium.
- Infracardiac (27%):
- Blood drains from the pulmonary veins to the right atrium via a vertical vein that passes inferiorly through the diaphragm
- This pulmonary venous blood must then pass through the liver to reach the IVC and right atrium. This pathway often causes obstruction to flow
- Confluence of pulmonary veins behind, but not connected to the left atrium.
- Could also connect via the IVC, ductus venosus, directly to the hepatic vein and either above or below the diaphragm
- Intracardiac (18%):
- Blood drains from the pulmonary veins to the right atrium directly via the coronary sinus, the vein that normally only drains the coronary veins of the heart muscle itself.
- Confluence of pulmonary veins behind, but not connected to the left atrium.
- Mixed (12%): Any other combination of pulmonary veins and venous connections
Clinical Presentation:
- Variable. Depends on the type of venous connections present and the degree of pulmonary venous obstruction.
- Severe obstruction:
- Cyanosis, respiratory distress, tachypnea
- Symptoms can appear early after birth
- Prominent S2, low blood pressure and diminished pulses, hepatomegaly
- Can lead to right heart failure
- Unobstructed:
- Tachypnea, poor feeding, failure to thrive, hypoxia
- Fixed split S2 (due to right ventricular overload), systolic ejection murmur w/diastolic rumble, hepatomegaly
- Usually a net left to right shunt
- Severe obstruction:
Diagnosis:
- Clinical presentation plus the following:
- Angiography: “gold standard” but is not used if less invasive tests like echocardiography, CT or MRI have appropriately proven the diagnosis. Often used in complex cases when other diagnostic tools have failed.
- Echocardiography: lack of normal pulmonary venous connections to the left atrium, dilated right atrium, any of the anatomic connections described below
- Chest X-ray is not the means to diagnose TAPVC, but if one is obtained, it can show the classic "snowman pattern"
Differential for Cyanotic heart disease + respiratory symptoms:
- Transposition of the Great Arteries
- Truncus Arteriosus
- Tetraology of Fallot
Management:
Medically stabilizing the neonate is important in initial management. Surgery is the definitive treatment.
- Goal: establish normal circulation where oxygenated blood is connected to systemic circulation via the left atrium
Outcomes:
- Very good outcomes but the surgical mortality is dependent on the complexity of the anomalous connections and obstruction present.
- 85-87% survival rate to 18 years of age
- Complications include reoperation due to pulmonary vein(s) stenosis and arrhythmia due to the nature of the initial surgery’s location in the electrical conducting system of the heart.
References:
- Hines, M. and Hammon, J.W. (2001). Anatomy of total anomalous pulmonary venous connection. Operat Tech Thorac Cardiovasc Surg, 6(1), 2-7.
- Shen, Q., et. al. (2012). Role of plain radiography and CT angiography in the evaluation of obstructed total anomalous pulmonary venous connection. Pediatric Radiology, Epub ahead of print.
- St. Louis, J., et. al. (2012). Repair of "simple" total anomalous pulmonary venous connection: a review from the Pediatric Cardiac Care Consortium. Ann Thorac Surg, 94(1), 133-138.