Though the exact reason has not yet been pinned but the cases of congenital heart defects is on the rise among newborn.
Research shows that nearly 1% babies are born with an imperfection in the heart’s structure.
It is a matter of great worry and anxiety for the parents about their child’s health and long-term future. Until recently, for the newborns only temporary repairs were done and the permanent treatment was postponed for a later time in childhood. However with the advancement in medical science and technology, corrective surgery, for babies as young as few days old, is a reality. Even severe defects can be treated now. This comes as a big respite for concerned parents.
What is congenital heart defect (CHD)?
We first need to understand how the heart works.
Human heart has four chambers – upper two are known as atrium and lower two are known as ventricles. Heart is divided into left and right halves so left half has – left atrium and left ventricle; and right half has – right atrium and right ventricle. There are four valves in the heart, which open on one-side; this is to allow blood to flow in one direction. Right side of the heart moves blood to the lungs through pulmonary arteries where it picks up oxygen and then return to the left side of the heart through pulmonary veins. The left side of the heart has a large artery called aorta which pumps this oxygenated blood to the entire body – each and every cell.
During pregnancy sometimes the structure of the heart is not properly formed. This leads to congenital heart defects. Congenital means ‘present at the time of birth’.
There are more than 35 types of CHD most of which fall under the following types:
- Holes in the walls of the heart chambers or in the blood vessels originating from the heart. If the hole is in the wall between right and left ventricles, it is called ventricular septal; between right and left atrium, it is called atrial septal. If the hole is between pulmonary artery and the aorta, it is called patent ductus arteriosus.
- Obstructed blood flow due to narrow blood vessels and valves. Pulmonary stenosis (narrowing of the pulmonary valve) and Aortic stenosis (narrowing of the aortic valve) are the most common ones.
- Abnormal formation of the blood vessels.
- Abnormalities in the heart valves due to which they are unable to open and close properly. Examples include Ebstein anomaly (malformation of tricuspid valve) and Pulmonary atresia (formation of a thin sheet of tissue instead of valve).
- Occurrence of more than one defect. Example, Tetralogy of Fallot is the most serious, as the name implies, it is a combination of all the above four types of defects stated above.
What are the causes of congenital heart defects?
The underlying causes of CHD are not yet clear but it is largely believed that certain environmental and genetic factors increase the risk.
- Chronic disease like diabetes.
- Rubella or German measles
- Certain medications such as anti-acne and anti-seizure drugs.
- Alcohol consumption during pregnancy
What are the symptoms of congenital heart defects?
Generally, heart defects are detected before birth through pre-natal diagnosis like fetal echocardiography. Otherwise other noticeable signs and symptoms in newborns include:
- Shortness of breath during feeding
- Poor weight gain
- Blue-grey skin color
- Breathing difficulties
- Swelling of legs, abdomen and around eyes.
How to diagnose congenital heart defects?
Congenital heart defects are usually suspected before birth during routine ultrasound. If suspected, then obstetrician suggests fetal echo-cardiogram to confirm the diagnosis. In case of newborns, chest X-ray, ECG and echo-cardiogram are done to check for heart defects.
Surgical Treatment for Congenital Heart Defect in Newborns
Though some CHD can be treated with medications but in severe cases surgery is recommended. Unlike before when only palliative treatment was possible for newborns, nowadays corrective surgery is a reality. Through early recognition of congenital heart defects in newborns as well as perinatal intensive care, newborns are taken to paediatric cardio-surgery department much faster after birth as compared to before.
Advancements in peri-operative, anaesthetic, post-operative care has helped to reduce the mortality rates. Peri-natal care helps to reduce effects of hypoxemia (lack of oxygen), to support failing heart and to enable blood circulation. With the availability of micro-surgical techniques to operate on newborns, even as old as few weeks, can undergo corrective surgery. Even post-operative techniques to stabilize vital functions of the body like renal, respiratory and circulatory as well as early nutrition of the newborn.
For severe cases of CHD like hypo-plastic left heart syndrome, the surgery is complicated and is performed in stages. There has been a dramatic improvement in the survival rates of the newborns with congenital heart defects.