Narayana Health Care

What is the Tetralogy of Fallot?

The heart is the vital organ of the body that pumps blood all through the body and collect back waste metabolites to be excreted. The heart has 4 chambers 2 upper atrium and 2 bottom ventricles. The atrium and ventricles are separated by valves, which provide unidirectional blood flow. The main purpose of the heart is oxygenation of blood. The left ventricle opens in the aorta that supplies oxygenated blood to the body via other arteries. The left ventricle and aorta are separated by an aortic valve.

Tetralogy of Fallot is a defect where four problems co-exist

1. A hole between the left and right ventricle
2. A blocked valve between the right ventricle and pulmonary arteries that take blood for oxygenation to lungs
3. Displaced aorta
4. A thickened right ventricular wall (right ventricular hypertrophy)

Causes of the defect

Idiopathic or unknown cause, but tend to coincide with down syndrome or DiGeorge syndrome. Other risk factors include

• A viral illness during pregnancy like rubella
• Alcoholism during pregnancy
• Poor nutrition during pregnancy
• A mother older than age 40
• A parent who has tetralogy of Fallot

How is Tetralogy of Fallot bad for my child?

Due to the hole between the left and right ventricle the oxygenated and deoxygenated blood mixes and less oxygenated blood is supplied to the body instead of being supplied to the lungs for oxygenation. Such children present as blue or cyanotic.

Presentation of the defect

• A heart murmur (abnormal heart sound)
• Bluish coloration of the skin caused by blood low in oxygen (cyanosis)
• Short and rapid breathing, especially during exertion like feeding or exercise
• Loss of consciousness (fainting)
• Clubbing of nails -fingers and toes —a rounded shape of the nail bed
• Poor weight gain
• Get tired easy
• Irritability
• Prolonged crying
• Tet spells- development of deep blue skin, nails, and lips after crying or feeding

How is it detected?

Symptoms are pretty evident but certain diagnostics are used to confirm its extent

• Chest X-ray- Heart looks like a boot due to enlarged right ventricle
• Echocardiography by a probe by sound waves
• Electrocardiogram
• Oxygen level measurement (pulse oximetry)
• Cardiac catheterization- a long thin tube called a catheter is inserted in an artery of groin, neck or arm that passage its way to the patient heart. A dye is then injected, making all defects detectable on an X-ray. It also measures the pressure and oxygen level of the heart. This can also be used as a treatment.

Treatment

Surgery is the only apposite cure of Tetralogy of Fallot.

1. Intracardiac Corrective repair of tetralogy of Fallot- It involves placing a synthetic Dacron patch to close the ventricular septal defect so that the blood can flow normally from the left ventricle to the aorta.

It also repairs or replaces the narrowed pulmonary valve and broadens the pulmonary arteries to enhance blood flow to the lungs.

2. Another temporary procedure is carried out in premature babies with underdeveloped pulmonary arteries. Here a shunt is created between a branch of aorta and pulmonary artery, which later can be reconstructed as above.

More often than not, the defect is cured but a series of complications may develop

• Backward flow of blood from pulmonary arteries back into the right ventricle
• Blood leakage through the tricuspid valve(from the left ventricle to the left atrium)
• Ventricular septal defects that may leak again and require re-repair
• Enlarged right ventricle or left ventricle (due to overload)
• Irregular heartbeats (arrhythmias)
• Coronary artery disease
• Aortic root dilation, in which the ascending aorta enlarges
• Sudden cardiac death

Due to the complications, regular follow up is extremely important. In many cases, re-surgery is required even more than once during the life span to relieve symptoms.

Lifestyle Modifications

• Create infection-free surroundings– The child too should not get any infection. A preventive dosage of antibiotics is helpful. A regular dental checkup is important too as it can cause heart infection (infective endocarditis)
• Precautions should be practiced while carrying out any strenuous activity like exercising
• Females with this defect may or may not tolerate pregnancy; therefore the decision should be approved with your cardiologist before planning.

Finding your little one to be in a grave danger like Tetralogy of Fallot is agonizing. But this is a battle that they have to fight. The chances of winning become extraordinary with you standing right by their side.

Dr. Rachit Saxena, Senior Consultant – Cardiac Surgery – Adult | Narayana Superspeciality Hospital, Gurugram