Tetralogy of fallot
Tetralogy of fallot (TOF) is a rare cardiac anomaly that refers to a combination of four related heart defects that commonly occur together at birth of baby.Infants and children with tetralogy of fallot have blue-tinged skin because their blood doesn’t carry enough oxygen.
This condition is often diagnosed during infancy or soon after.
The four defects are main cause of this condition –
• Ventricular septal defect (VSD) –
It is a hole between the right and left pumping chambers of the heart.
• Overriding aorta –
The aortic valve is enlarged and appears to arise from from the left and right ventricles instead of the left ventricleas in normal hearts.
• Pulmonary stenosis –
It is the narrowing of the pulmonary valve and outflow tract or area below the valve. It creates when an obstruction of blood flow from the right ventricle to the pulmonary artery
• Right ventricular hypertrophy –
Finally, the thickening of the muscular walls of the right ventricle occurs because of high pressure of pumping at high on right ventricle.
Which chromosome is the cause of this condition?
Tetralogy of Fallot may be associated with Chromosomal abnormalities, such as 22q11 deletion syndrome.
Physiology of Tetralogy of Fallot-
The pulmonary stenosis and right ventricular out flow tract obstruction usually limits blood flow to the lungs.
When blood flow to the lungs is restricted, the combination of the ventricular septal defect and overriding aorta allows poor-oxygen blood returning to the right atrium and right ventricle to be pumped out the aorta to the body.
This shunting of poor-oxygen blood from the ventricle to the body results in a reduction in the arterial oxygen saturation, due to which finally
the babies appear cynotic or blue.
The cynonsis occurs because poor-oxygen blood is darker . Additionally has a blue color, as a result the lips and skin appear blue.
The extent of cynosis is dependent on the amount of narrowing of the pulmonary valve and right ventricular outflow tract.
The symptoms of this condition vary, depending on the extent of obstruction of blood flow out of the right ventricle and into the lungs. Signs and symptoms may include-
1 • A bluish coloration of the skin caused by blood low in oxygen (Cynosis)
2 • Shortness of breath and rapid breathing, especially during feeding or exercise
3 • Clubbing of fingers and toes – an abnormal rounded shape of the nail bed
4 • Loss of consciousness (fainting)
5 • Prolonged crying
6 • A heart murmur
7 • Poor weight gain
8 • Tiring easily while playing or exercise
9 • Irritability
Sometimes, diseased babies suddenly develop deep blue skin, nails and lips after crying or feeding, or when agitated.These episodes are called Tet spells.
Tet spells are caused by a rapid drop in the amount of oxygen in the blood. These spells are most common in young infants, around 2-4 months old.
Risk factors –
The various reasons which might increase the risk of a baby being born with this condition as follows-
1. Viral infection named rubella during pregnancy
2. Alcoholism during pregnancy
3. Poor nutrition during pregnancy
4. Mother oIder than 40 yrs
5. Parent having tetralogy of fallot
6. The presence of Down syndrome in baby
Your baby may be also at an increased risk of serious complications, such as infective endocarditis – an infection of the inner lining of the heart or heart valve carried by a bacterial infection.
Untreated cases might develop serious complications, which ultimately result in death or disability by early adulthood.
The doctor will conduct a physical examination and advise you for several tests to confirm the diagnosis which are as follows-
3. Chest X-ray
4. Oxygen level measurement
5. Cardiac catheterization
Surgery is the only effective treatment for tetralogy of fallot.Doctor will determine the most appropriate surgery and the timing of the surgery based on your child’s condition.
Surgical options include –
2.a temporary procedure
isolated birth defects that uses a shunt.
While most babies and adults do well after intracardiac repair, long complications are common.They may include-
1. Chronic pulmonary regurgitation
2. Other heart valve problems, such as blood leaking back through the tricuspid valve
3. Holes in the wall between the ventricles
4. Enlarged right or left ventricle
5. Irregular heartbeats
6. Coronary artery disease
7. Aortic root dilation
8. Sudden cardiac death
Most adults with repaired condition may have pulmonary valve replaced during their lifetimes.
Arrthymias are common after repair and may be treated with medications, a procedure to treat the arrhythmias or a special pacemaker device which finally treats the life threatening heart rhythms.
In addition,as like with any surgery, there’s a risk of infection, unexpected bleeding or blood clots.
Routine care –
After surgery your child will need lifelong care with a cardiologist. You may need to conduct a physical examination. The tests in regular follow up appointments to evaluate and monitor your child’s condition.
The doctor may recommend that you child should limit strenuous physical activity.
Antibiotics are especially important for those who have had prior endocarditis. Additionally for the people who have artificial valves or have had repair with prosthetic material.