From the Guidelines
Partial Anomalous Pulmonary Venous Connection (PAPVC) and Total Anomalous Pulmonary Venous Connection (TAPVC) are distinct congenital heart defects with different implications for morbidity, mortality, and quality of life, with TAPVC being more severe and life-threatening than PAPVC. The key difference between PAPVC and TAPVC lies in the extent of anomalous pulmonary venous connections, with PAPVC involving one or more pulmonary veins connecting to the right atrium or systemic veins, and TAPVC involving all pulmonary veins connecting to the right side of the heart 1.
Key Characteristics of PAPVC and TAPVC
- PAPVC:
- Involves one or more pulmonary veins connecting abnormally to the right atrium or systemic veins
- Typically affects 1-3 veins, with the remaining veins connecting normally
- Creates a partial left-to-right shunt, causing increased blood flow to the right heart and lungs
- Often produces mild symptoms like exercise intolerance or may be asymptomatic
- TAPVC:
- Involves all pulmonary veins connecting abnormally to the right side of the heart
- Results in complete mixing of oxygenated and deoxygenated blood and requires an atrial septal defect for survival
- Typically causes cyanosis, respiratory distress, and heart failure shortly after birth
- Always requires urgent surgical repair to redirect all pulmonary veins to the left atrium
Treatment and Prognosis
Surgical correction is always necessary for TAPVC, whereas PAPVC may not require intervention if mild, but significant shunting necessitates surgical correction. The prognosis is generally better for PAPVC than for TAPVC, which can be life-threatening without prompt intervention 1.
Imaging and Diagnosis
Advanced imaging plays a crucial role in the diagnosis and management of both PAPVC and TAPVC, particularly in defining surgical anatomy and detecting potential complications or associated abnormalities 1.
From the Research
Difference between PAPVC and TAPVC
The main difference between Partial Anomalous Pulmonary Venous Connection (PAPVC) and Total Anomalous Pulmonary Venous Connection (TAPVC) lies in the connection of the pulmonary veins to the heart.
- In PAPVC, some of the pulmonary veins connect abnormally to the vascular compartments other than the left atrium, while others drain normally into the left atrium 2.
- In TAPVC, all the pulmonary veins connect abnormally to the vascular compartments other than the left atrium, resulting in severe pulmonary hypertension and poor prognosis 3.
Clinical Presentation and Severity
The clinical presentation and severity of PAPVC and TAPVC depend on the morphological heterogeneity of the disease.
- PAPVC associated with other complex congenital cardiac diseases presents early and is more severe than isolated PAPVC-associated atrial septal defect only 2.
- TAPVC, especially the infradiaphragmatic type, has a poor prognosis and is related mainly to the existence of pulmonary venous obstruction 3.
Diagnosis and Treatment
Diagnosis of PAPVC and TAPVC can be made using various imaging modalities such as echocardiography, AngioCT, and multidetector computed tomography angiography.
- A customized approach to repair PAPVC, taking into account atrial shunt and growth potential, can maximize efficiency and reproducibility paired with the lowest morbidity 4.
- Prenatal diagnosis of TAPVC and PAPVC can be made using comprehensive ultrasound examination, and the outcome is generally favorable for PAPVC, but less than half of TAPVC cases have a favorable outcome 5.