By Dr Sarat Ku Sahoo, HOD Department of Cardiac Sciences, SUM ULTIMATE
Congenital heart defects (CHDs) are heart abnormalities present at birth that can affect the way the heart works. Congenital heart diseases are the most common congenital anomalies, with an estimated prevalence of 8 in 1000 live births. They are the most common birth defects responsible for one-third of congenital birth defects. The number of children born with CHD in India is 2, 40, 000. 10% of the infant mortality rate in India is due to CHD. These heart defects can affect the heart’s shape or how it works and can range from simple to complex.
Congenital heart defects can affect the baby’s heart, including the heart walls, the septum, and heart valves, and can cause blood vessel defects and affect the arteries. Some babies will have a combination of defects. This can also cause Complex CHD – computation of defects in heart valves, heart walls and blood vessels. The presence of such heart defects in a child can comprise the blood flow, causing the child’s blow flow to slow down or get blocked, or cause it to flow in the wrong direction. It may also lead to the child’s blood not having enough to cover the body.
Some heart defects don’t need treatment or can be treated easily. But others, like some critical CHDs, may need surgeries over several years. There are two types of CHDs. First is Cyanotic congenital heart disease. It is a form of critical congenital heart defect (CCHD) that reduces the amount of oxygen delivered to the baby’s body. It causes a blue discolouration of the skin and the baby also experiences breathing difficulties. Cyanotic CHD is usually present at birth and due to complex heart defects affecting multiple heart structures, the baby would need immediate surgical intervention after birth to correct this condition and improve blood flow to the lungs and the rest of the body.
The second type of Congenital heart disease is Acyanotic congenital heart disease. Acyanotic heart defects are congenital cardiac malformations that affect the atrial or ventricular walls, heart valves, or large blood vessels. The condition is present at birth but may not cause any symptoms or problems until later in life. It causes a pinkish discolouration of the skin. A hole in the heart wall is a kind of Acyanotic heart defect.
In some cases, symptoms of CHD will appear shortly after birth. The symptoms that present shortly after birth are bluish lips, skin, fingertips, and toes, breathlessness, feeding difficulties, low birth weight, chest pain, delayed growth, and clubbed or rounded large fingers. In other cases, symptoms manifest many years after birth. The symptoms could be abnormal heart rhythm, dizziness, breathlessness, fainting, swelling of the feet and fatigue, to name a few.
Causes of CHD
CHD occurs because of a developmental problem in the heart’s structure. Causes may be :
- Some babies have heart defects because of changes in their chromosomes or genes. Certain gene changes (also called mutations) are linked to heart defects. Genetic factors may run in the family. Certain genetic syndrome are associated with CHDs. For Examples- Down Syndrome, and Turner Syndrome.
- Taking certain drugs during pregnancy
- Drinking alcohol during pregnancy or smoking before or during pregnancy
- Exposure to toxic chemicals
- Viral infection of the mother during first trimester of pregnancy
- Diabetes Mellitus of mother.
Advances in pediatric cardiology and cardiac surgery have made it possible to repair or palliate most of the CHDs including complex ones. If access to screening early diagnosis and treatment is available, over 90 % of patients born with CHD survive to adult life with good long-term outcomes.
Treatment of congenital heart defects in children depends on the specific type of heart problem and how severe it is. Treatment may involve medications, heart procedures or surgeries, or a heart transplant. Medications may be given to treat symptoms or complications of a congenital heart defect. Some babies have mild defects that heal on their own with time. A tiny ventricular septal defect (VSD) or a small atrial septal defect (ASD) can often be left alone, but larger ones may require a procedure or heart surgery to close them.
Serious congenital heart defects require treatment soon after they’re diagnosed. Heart procedures and surgeries done to treat congenital heart defects include:
Catheter procedure (Percutaneous cardiac intervention)- It is a safe method and is performed by making small holes in the arteries and veins without surgically opening the chest and heart. The procedure is done by inserting a small tube into the heart through arteries or veins. When there is a hole inside the heart (ASD, VSD, PDA) it can be closed with umbrella-like devices which is dislodged across the defect. This procedure leaves no scar on the chest. It has a shorter hospitalisation period and the patient can resume normal activities within 2-3 days. Most of the holes inside the heart can be closed by this method.
When a valve is blocked, it can be opened by inflating a balloon over the valve using procedures like Aortic Valvotomy and Pulmonary Valvotomy. When heart vessels are blocked, it can be opened by putting stents like the Coarctation of aorta stenting and pulmonary artery stenting.
Most acyanotic CHD can be treated by this catheter procedure without open heart surgery. Few cyanotic CHD can be treated by catheter procedures to make the patient fit for open heart surgery.
Open heart surgery is done when a catheter procedure is not enough to repair a congenital heart defect. Open heart surgery is done in case of complex CHD, actually cyanotic CHD. If a serious heart defect can’t be repaired, a heart transplant may be needed. Implantable Heart Devices like pacemakers and implantable cardioverter-defibrillators are also an option to treat CHDs.
As so we know little about the causes of congenital heart disease, the emphasis is on prevention. Women who are pregnant or planning to become pregnant can take certain precautions to lower the risk of giving birth to a baby with CHD.
- Avoid taking drugs without consulting a doctor
- Bring your blood sugar under control.
- Vaccinate against Rubella or German Measles
- If have a family history of CHD do genetic screening.
- Avoid alcohol intake and illegal drugs during pregnancy.