Total Anomalous Pulmonary Venous Return (TAPVR)

Total anomalous pulmonary venous return (TAPVR)

Total anomalous pulmonary venous return (TAPVR) is a rare congenital heart defect (a defect that is present in the heart at the time of birth) in which the blood vessels of the lung are connected to the wrong place in the heart. Sometimes it is also referred to as Total Anomalous pulmonary venous connection (TAPVC). In normal conditions, the pure oxygenated blood from the lungs is transferred to the left atrium (upper left chamber of the heart). Then from here, the blood flows through the whole body. Whereas in Total Anomalous pulmonary venous return, the pure blood from the lungs is delivered to the right atrium (upper right chamber) of the heart, where it gets mixed with the impure (deoxygenated) blood. As a result, the blood flowing in the body has less oxygen. Hence oxygen is deficient in the body.

There are three types of Total Anomalous Pulmonary Venous return:

1. Supracardiac: In this condition, the blood is drained into the right atrium by the pulmonary veins through the superior vena cava.
2. Cardiac: In this condition, the pulmonary veins either drain the blood directly to the right atrium, or it may drain the blood into the coronary sinus, which then carries the blood to the right atrium. 
3. Infracardiac: In this condition, the blood is drained into the right atrium by the pulmonary veins through the inferior vena cava and hepatic veins.

The infant who has Total Anomalous pulmonary venous return may appear sick and experience the following symptoms. In some cases, the symptoms may also be not present in infants and during early childhood. However, if present, it may include:

1. The skin, lips and nails of the infant become bluish.
2. Frequent respiratory infection
3. Signs of lethargy can also be noticed in the infant
4. Retractions of the rib cage muscles
5. Poor feeding
6. Rapid Breathing
7. Restricted growth in the child
8. Cool and clammy skin
9. Poor pulse
10. Increased heart rate
11.  Enlarged liver 
12. Heart murmur

Some of the risk factors that can increase the chances of developing the Total Anomalous pulmonary venous return in the infant are:-

1. Smoking: Quit smoking if you are pregnant.
2. Family history: Congenital heart disease can sometimes run in the family. So, if there is a history of such defects in your family, you must discuss it with your gynaecologist.
3. Medicines: Certain medicines taken during pregnancy can also increase the chances of congenital heart diseases. Therefore, you must discuss the medicines you are taking with your doctor.
4. Other risk factors: The other risk factors for TAPVR include alcoholism and obesity.

Despite all advancements in research and development, causes of congenital heart diseases like Total Anomalous pulmonary venous (TAPVR) are still not known. In addition, some babies have a defective heart because of altered genes and chromosomes during the gestational period (pregnancy).  

Some of the possible causes of Total Anomalous pulmonary venous are:

1. Smoking, alcoholism and obesity during pregnancy.
2. Rubella infection
3. Inadequate prenatal care
4. High blood sugar
5. Lack of essential minerals and vitamins, such as folic acid
6. Certain medications that can adversely affect the fetus

Total Anomalous pulmonary venous return can be diagnosed during pregnancy, but it is diagnosed soon after the pregnancy in most cases. 

1. Diagnosis during pregnancy: During pregnancy, some imaging tests can also be performed, known as prenatal tests. These tests are done to detect the birth defect in the baby. It can also be diagnosed by ultrasound. An ultrasound known as a foetal echocardiogram is specially designed for checking the baby's heart and major blood vessels. 
2. Diagnosis after the birth: The diagnosis after the birth can be detected by observing  the following symptoms:
   1. Breathing problem
   2. Weak pulse
   3. Decreased appetite
   4. Extreme sleepiness

The type of total anomalous pulmonary venous return (TAPVR) plays a role in deciding the timing of the surgical repair.

1. Some newborns suffering from TAPVR, prior to surgery, may require extracorporeal life support due to instability in blood flow.
2. Children with restrictive atrial septal defect along with TAPVR may require a balloon dilation procedure.
3. TAPVR is a defect that can only be corrected by the surgical method. 
4. It is done on an emergency basis in children who have a blockage in their blood vessels after birth. The surgery is done after a few weeks of diagnosis for the child who does not have a blockage in the blood vessels.
5. Children who do not have any blockage in the blood vessel are firstly treated for heart failure. After that, the surgery to correct the connection of the heart is done after the children are stabilised.
6. In the surgical repair, a wide anastomosis (the surgical connection between two structures) is between the pulmonary veins (blood vessels of the lungs) and the posterior wall of the left atrium. 
7. Similarly, all the veins of the lungs that carry oxygen-rich blood are connected to the right place in the left atrium. Thus establishing a normal connection. All the other extra abnormal veins of the lungs are tied up.
8. The atrial septal defect is also closed. In addition, this surgery helps establish normal circulation in the body.

You must consult a doctor nearby your locality in case you are experiencing any of the following symptoms:-

1. Irregular and fast heart rhythms. Also called arrhythmia.
2. Decrease in appetite
3. Indication of pulmonary hypertension (high blood pressure that affects the arteries of the lungs).
4. Rapid breathing.
5. If the skin of the child is getting blue
6. If the heart rate is consistently increased

Complications

The complications of Total Anomalous pulmonary venous return depend upon the underlying pathophysiology of the disease.

1. Total Anomalous pulmonary venous return Without Pulmonary Venous Obstruction: The complications include feeding difficulty, dyspnea and cyanosis of varying degrees. As the disease progresses, the patients may experience right ventricular failure features and right ventricular hypertrophy.
2. Total Anomalous pulmonary venous return with Pulmonary Venous Obstruction: These patients have cyanosis and severe respiratory distress. The patients may also experience hypotension, tachypnea and hypoxia indicating persistent pulmonary hypertension. These patients are generally sick and require urgent medical interventions.

Disease Progression

If Total Anomalous Pulmonary Venous Return is not treated on time, the heart will become larger, which will eventually lead to heart failure. Repairing the defect in the early stages provides a very good and satisfactory result if there is no blockage in the blood vessels of the child. Survival chances are low in infants who have an obstruction in their blood vessels. 

You must consult a doctor nearby your locality in case you are experiencing any of the following symptoms:-

1. Irregular and fast heart rhythms. Also called arrhythmia.
2. Decrease in appetite
3. Indication of pulmonary hypertension (high blood pressure that affects the arteries of the lungs).
4. Rapid breathing.
5. If the skin of the child is getting blue
6. If the heart rate is consistently increased