Latest Advances in Diagnosing Congenital Heart Defects

Did you know that your heart starts beating even before you’re born? Yes, the body’s pumping organ begins to develop by the third week of pregnancy, and within five to six weeks, those tiny heartbeats can be detected on an ultrasound. 

However, sometimes, during this critical period, structural abnormalities can develop, leading to congenital heart defects (CHD).

Congenital Heart Defect: An Overview

Congenital heart defect (CHD) arises as a result of abnormal formation of any part of the heart. This can affect the heart’s chambers, valves, or arteries. As a result, blood flow through the heart may be disrupted.

CHD is the most common congenital condition, with an estimation suggesting that 8 out of 1,000 infants are born with congenital heart disease. About 1/4th of the babies with CHD need surgery or other medical procedures soon after birth.

Common Symptoms of CHDs

Like any other heart condition, based on the severity and type of defect, congenital heart conditions may appear at different stages of life. 

There are some chances for severe forms of CHD to be detected during pregnancy, but others can’t be detected until the child is born. Let’s discuss the common symptoms of CHDs associated with different age groups.

In Infants and Children

• Cyanosis: Skin, lips, or nails of the newborn turn blue due to insufficient oxygenated blood
• Fatigue: Extreme tiredness
• Heart murmur: An abnormal noise along or with the heartbeat
• Delayed growth: The rate of physical and mental development is reduced as compared to a healthy child
• Frequent infections: Recurring respiratory or ear infections.

In Adults

In some cases, adults face severe cardiac issues associated with CHDs, which go unnoticeable during earlier stages of life.

• Shortness of breath
• Fatigue
• Heart palpitations
• Swelling in the legs, ankles, or abdomen.
• Chest pain or discomfort

Congenital Heart Defect: Types

Based on the interruption in blood supply to the foetus, CHDs in children can be categorised into two- Acyanotic (Pink baby) and Cyanotic (blue baby).

Acyanotic CHDs

In this condition, the flow of blood in the newborn is affected. The types of acyanotic heart defects include:

• Atrial septal defect (ASD): A hole is present in the wall between the upper chambers of the heart.
• Ventricular septal defect (VSD): In VSD, a hole is present in the wall between the lower chambers of the heart.
• Patent ductus arteriosus (PDA): In thai condition, the opening between the aorta and pulmonary artery persists which should have been closed soon after birth.
• Coarctation of the aorta: A narrowing of the aorta leads to difficulty in blood flow.

Cyanotic CHDs

In this condition, there is not enough oxygenated blood in the body, resulting in the appearance of a blue-coloured tinge in areas such as their fingers, toes and lips. The types of cyanotic CHDs include:

• Tetralogy of Fallot: A combination of four heart defects that can lead to cyanosis, especially during periods of stress or exercise. These defects include ventricular septal defect, overriding aorta, pulmonary stenosis and right ventricular hypertrophy.
• Transposition of the great arteries: In this rare condition, the aorta and pulmonary artery are reversed, resulting in mixed blood flow and cyanosis.
• Tricuspid atresia: A condition where the tricuspid valve is absent or underdeveloped, preventing proper blood flow from the right atrium to the right ventricle.

Causes of Congenital Heart Defects

The cause of CHDs can be attributed to genetic defects that could be both hereditary or sudden mutation during the gestation period. The exact reason behind this sudden DNA change is idiopathic and is unknown. However, the risk factors giving rise to CHD are:

Genetic Factors

• Family history: Many instances have suggested that having a family member with a CHD or other genetic conditions may increase the risk of having CHD in children as well.
• Chromosomal abnormalities: Down syndrome (trisomy 21) or Turner syndrome (monosomy X) are often associated with CHDs.An estimate suggests that people with Down syndrome have 50 times higher chances of developing CHD.

Environmental Factors

• Medication use: Some medications taken during pregnancy, especially in the first trimester, can be associated with CHDs.
• Substance abuse: Consuming alcohol, tobacco, or illicit drugs during pregnancy can significantly increase the risk.
• Exposure to toxins: Exposure to certain environmental toxins, such as lead or mercury, can also be a risk factor.

Maternal Factors

• Maternal age: Women more than the age of 35 or below the age of 20 are at a slightly higher risk of giving birth to a child with a CHD.
• Maternal health: Certain maternal health conditions, such as diabetes, hypertension, or infections during pregnancy, can increase the risk.

Diagnosis of Congenital Heart Defect

While newer technologies have emerged, traditional methods, such as Chest X-ray, Echocardiogram, Electrocardiogram (ECG), MRI, cardiac computed tomography, and cardiac catheterisation, remain essential in diagnosing congenital heart defects.

Recent technological advancements have revolutionised the diagnosis of congenital heart defects:

• Foetal Echocardiography

During the 11th-13th month of pregnancy, if an ultrasound detects fluid in the baby’s neck, the gynaecologist immediately suggests foetal echocardiography. This non-invasive technique allows doctors to examine the foetus heart in the womb.

• Cardiac MRI

Magnetic resonance imaging (MRI) is performed to generate detailed images of the heart and surrounding structures. It is particularly useful in case of complex heart defects and for assessing whether the treatment is effective or not.

• Cardiac CT

Computed tomography (CT) scans offer high-resolution images of the heart and blood vessels. They are helpful in understanding the blood flow and diagnosing coronary artery issues.

These advancements, combined with traditional methods, offer a comprehensive approach to diagnosing congenital heart defects, giving hope to families and paving the way for improved treatments and outcomes.

• Pulse oximetry

In this method, pulse oximeters are used to measure oxygen saturation without drawing blood, making them safe and convenient for children.

Treatment of CHDs

About 1/5th of atrial septal defects will get repaired spontaneously when the child is one year old or with age. Hence, for mild defects, regular check-ups to monitor the child’s growth and development is recommended.

However, some other congenital heart conditions may require some medical attention to ensure that the child leads a healthy life. Some of the treatment measures for CHDs are-

Medications

In some cases, medications can help manage symptoms that arise as a result of CHDs to improve heart function. These medications may be categorised as:

• Diuretics: To reduce fluid buildup
• Beta-blockers: To slow the heart rate
• Digoxin: To strengthen the heart’s contractions

Surgical Treatment

If the heart defects cannot be fixed by medication, immediate surgical intervention may be required. Common surgical procedures for CHDs include:

• Ventricular septal defect (VSD) and Atrial septal defect (ASD) repair: The hole in the heart may be covered by a patch. This patch is made up of the body’s own graft or also can be derived synthetically. In some severe cases, sutures can be used to stitch the excess hole.
• Tetralogy of Fallot repair: The four defects that make up this condition are corrected. The repair is carried out in four steps, which include the following-
  • First of all, with the help of a patch, the hole between the lower heart chambers is closed.
  • Then, the pulmonary valve is widened.
  • Then, the calcified thick tissue from the right ventricle is removed.
• Coarctation of the aorta repair: The narrowed section of the aorta is widened.
• Glenn procedure: This surgery is performed when the child is 4-6 months old and is suffering from hypoplastic left heart syndrome (HLHS), tricuspid atresia, and double outlet right ventricles.
• Fontan procedure: Some children are born with only one functioning heart ventricle. To treat this condition, the Fontan procedure is performed. After the surgery, all deoxygenated blood is diverted to the lungs instead of going to the heart first.

Catheter-based procedures

It is based on the minimally invasive procedures in which a thin tube with a catheter is inserted. This approach repairs certain congenital heart conditions without open-heart surgery. Some examples include:

• VSD and ASD closure: A device is inserted through a blood vessel to close the hole in the heart.
• Patent ductus arteriosus (PDA) ligation: A coil is placed in the PDA to close it.

The cost of congenital heart defect treatment in India varies depending on the procedure or combination of procedures involved in saving the life of the newborn.

Conclusion

With advancements in medical technology, diagnosing congenital heart defects (CHDs) has become increasingly accurate and efficient. These advancements have enabled earlier detection, leading to more timely and effective treatments. 

India has made significant strides in paediatric cardiology, with top CHD treatment hospitals in India , offering advanced diagnostic facilities and treatment options for CHD.

This progress ensures that more children can be diagnosed early and provided with the best treatment facility as soon as possible.