Congenital Heart Defects (CHD): A Complete Guide

Studies from the American Heart Association show that 9 out of 1000 babies are born with congenital heart defects.

According to data collected from the Global Burden of Disease study in 2017, congenital is more prevalent in developing countries and lower in developed countries. Generally, heart issues are found in 0.8% to 1.2% of live births worldwide.

What are congenital heart defects?

Congenital refers to something that is present from birth. Congenital heart disease is, therefore, a birth defect in the heart that affects the normal way a heart works.

It is basically an abnormality or defect that happens at birth, and this problem causes structural issues like holes in the heart or leaky valves.

It may present as a structural or functional abnormality in a baby’s heart which might disrupt the overall blood flow within the body.

What are the types of congenital heart defects?

Congenital heart defects can be broadly divided into three main categories:

Heart valve defects - These happen when a valve in the heart is too narrow (example- aortic coarctation) or closed (example- bicuspid aorta). This causes an inability within the heart to pump blood correctly. In some instances, the valve is not able to close properly, which causes the blood to leak backward (example- aortic regurgitation).

Heart wall defects - There is a natural wall that separates the left and right sides of the heart chambers. When there is a defect, the wall does not develop properly, causing the pure and impure blood to mix. It may also cause blood to back up in the heart or build up in places where it shouldn't. The heart, therefore, has to work harder, causing high blood pressure.

Blood vessel defects - When this happens, the arteries and veins that carry blood from the body to the heart and back may not function properly, leading to various complications of the heart.

What are the common congenital heart defects?

1. Atrial Septal Defect (ASD)

In simpler terms, this condition is called ‘a hole in the heart’. The hole appears between the heart’s two upper chambers called the left and right atria and causes an abnormal blood flow through the heart.

2. Atrioventricular Septal Defect

This is a congenital abnormality in the structure of the heart where there are holes between the right and left ventricles. This hole that results due to the congenital malformation in the fetus is also called the atrioventricular canal.

3. Bicuspid aortic valve

A normal aortic valve has three cusps, known as the tricuspid aorta. However, in some babies, one of the cusps may either not be developed enough to function or be closed. As a result, the bicuspid aortic valve has only two functional cusps, which cause the normal flow of blood to be disrupted.

4. Coarctation of the Aorta

This is a condition whereby the aorta, which is the main artery in our heart, becomes narrow or constricted.

5. Congenital mitral valve anomalies

The Mitral valve (or the atrioventricular valve) is the one between the heart’s left atrium and left ventricle. Birth defects in this valve include narrowing of the valve (mitral valve coarctation) or leaky mitral valve (mitral valve regurgitation).

6. Double-outlet Right Ventricle

This condition is present at birth. In normal conditions, the aorta connects to the left ventricle (the chamber that pumps oxygen-rich blood to the body). However, in this condition, the aorta is wrongly placed and connects to the right ventricle instead.

7. d-Transposition of the Great Arteries

This is a defect where the main pulmonary artery and the aorta switch positions or are ‘transposed.’

8. Ebstein Anomaly

This is a rather rare form of congenital heart disease where the heart valve does not develop properly. When this happens, the leaflets of the tricuspid heart valve are malformed and do not work well. As a result, blood may leak backward from the valve.

9. Eisenmenger syndrome

This is a congenital defect that causes blood to flow abnormally in the heart and lungs. It makes the blood vessels in the lungs to become stiff and narrow and increases the pressure in the lungs’ arteries.

10. Hypoplastic Left Heart Syndrome

This is a rather complex defect as it is a combination of several abnormalities of the left chambers of the heart. In this condition, the aorta and left ventricle are too small and underdeveloped, while the septum does not mature and close well enough. Therefore, not enough blood is pumped into the body. This condition, if not treated urgently, could also be fatal.

11. Interrupted Aortic Arch

When a part of an aorta is missing in a baby, the condition is called Interrupted Aortic Arch. This condition needs surgery right after birth as the heart will not be able to send blood from the aorta to the rest of the body.

12. Pulmonary Atresia

It is a condition where the pulmonary valve does not exist. It, therefore, causes a problem for the blood to flow to the lungs and pick up oxygen for the body.

13. Pulmonary valve stenosis

The pulmonary valve’s function is to control the flow of blood out of the right heart towards the lungs. When there is a defect, the valve is narrower than normal, causing the right side of the heart to work harder.

14. Single Ventricle

This is a rather severe defect that can be fatal within the first few weeks of birth. A single ventricle is a defect whereby only 1 of the ventricles (pumping chambers at the bottom of the heart) develops properly.

15. Tetralogy of Fallot

As the name suggests, tetra means 4. This condition is rare and is a combination of several defects like:

  • A hole between the left and right ventricle
  • Narrowing of the pulmonary valve
  • Thickening of the right ventricle muscles
  • The aorta is not in its correct position
16. Total Anomalous Pulmonary Venous Return (TAPVR)

There are four veins that take oxygenated blood from the lungs to the heart. TAPVR occurs when these four veins are connected in the wrong way, causing blood to enter the wrong chambers or leak.

17. Tricuspid Atresia

The normal blood cycle of the heart is; heart-lung-heart-body. If a baby has Tricuspid Atresia, the valve that controls this flow doesn’t form at all. Hence, the blood cannot flow in the normal way.

18. Truncus Arteriosus

This condition occurs when the two main arteries (pulmonary and aorta) fail to develop properly and instead remain as a single vessel.

19. Ventricular Septal Defect (VSD)

The ventricular septum is the wall that divides the two lower chambers of a heart. VSD occurs when there is a hole in this wall that causes extra blood to be pumped into the right ventricle. It, therefore, creates congestion in the lungs.

20. Vascular rings

When the aortic arch in the main blood vessel does not form properly, it may branch out and encircle the windpipe (trachea). This condition is known as trachea rings.

21. Kawasaki disease

It is a condition in which inflammation occurs in coronary arteries, which supply oxygen-rich blood to the heart.

22. Long QT syndrome (LQTS)

LQTS is a heart rhythm condition that can cause fast, chaotic heartbeats, which can also lead to death.

23. Partial anomalous pulmonary venous return (PAPVR)

In this heart defect, some of the lung blood vessels are attached at the wrong place in the heart.

24. Patent ductus arteriosus (PDA)

This is basically an unclosed hole in the aorta. Every baby is born with ductus arteriosus, and it closes within a few days of birth. However, it may remain open in some cases of premature births. It may then require closure through medications or catheterization.

25. Patent foramen ovale

This is a hole in the heart that failed to close after birth. A foramen ovale is present in the right and left top chambers as a baby grows in the womb. However, if it does not close normally as it should, it results in a patent foramen ovale.

26. Wolff-Parkinson-White (WPW) syndrome

This is a condition that causes tachycardia (fast heartbeat). An extra signaling pathway between the upper and lower chambers of the heart causes a fast heartbeat.

What are the causes of congenital heart defect?

A baby’s heart develops during the first eight weeks of pregnancy. Should a defect happen to the fetus, it normally occurs during this crucial time.

There are a few reasons for congenital heart defects to happen in a baby.

One reason is when there are changes in the baby’s genes or chromosomes. This is sometimes hereditary and is passed on from either parent. The most widely known genetic condition that can cause a defect is Down’s syndrome. Besides that, Turner and Noonan's syndrome are also associated with congenital heart defects.

How do congenital heart defects develop in a fetus?

In many cases, the exact reason as to why this phenomenon occurs is unknown, but there are a number of risk factors that cause it. Let’s learn about these.

mom with daugther
Risk factors

Heart defects in babies can occur when the mother takes certain medications.

For example, taking ibuprofen or benzodiazepines is linked to an increased risk of a baby being born with a defective heart.

Consumption of alcohol, smoking, or illicit drugs is also known to increase the risk.

Additionally, all women are encouraged to take the flu vaccine before they get pregnant, as getting the flu during the first trimester may pose a risk towards congenital heart defects.

What are the signs and symptoms of congenital heart defect?

Symptoms in adults
  • Rapid breathing
  • Fast pulse rate
  • Swelling in hands, ankles, legs, feet, stomach, or other body parts
  • Shortness of breath during exercise
  • Fatigue
  • Fainting during exercise
  • Blue tinge on nails, lips, etc.
Symptoms in children

Newborns with heart defects may experience bluish lips, skin, fingers, and toes. They could have trouble breathing or feeding, very low birth weight, rapid breathing, or heartbeat.

Sometimes symptoms of congenital heart defects do not appear until a couple of years after birth, and once they start to develop, you would experience extreme tiredness or fatigue, fainting, or swelling in the hands, ankles, or feet.

How is congenital heart defect diagnosed?

Some congenital heart defects can be diagnosed during pregnancy by ultrasound using a fetal echocardiogram that creates ultrasound pictures of the developing heart of the baby. Your doctor may also want to conduct certain physical examinations.

Following are some tests to diagnose a heart defect in a newborn or adult which includes:

  • Electrocardiogram (ECG) - It is used to diagnose irregular heartbeats and blocked arteries and is done while you are on a bike or treadmill. It is also called a stress test.
  • Chest X-Ray - This test shows any changes in the size and shape of the heart and lungs.
  • Pulse oximetry - It is simply a sensor that is attached to your finger. It can estimate the amount of oxygen in your blood.
  • Echocardiogram - his test creates ultrasound images of the heart to see how the heart’s chambers and valves are pumping blood.
  • Transesophageal echocardiogram - This test provides a more detailed image of the heart. A flexible tube containing a transducer is put down your throat and into the tube connecting your mouth to your stomach. This is done under sedation.
  • Cardiac CT scan and MRI - These tests are done to create images of your chest and heart in order to see any abnormalities in it.
  • Cardiac catheterisation - This is used to check blood flow and blood pressures in your heart. A dye is injected into a catheter that helps to show any blockages in the blood vessels.

What are the treatment options for congenital heart defect?

With the highly equipped medical technology and high standards of medical science we have these days, most (if not all) congenital heart defects can be treated if caught at the right time.

The type of treatment depends on the severity of the defect. Some of the available treatment options include:

  • Medications
  • Implantable heart devices
  • Catheter procedures
  • Open heart surgery
  • Heart transplant

What is the life expectancy for congenital heart diseases?

The survival rate of infants with congenital heart disease depends on the severity of the defect, when the diagnosis takes place, and also how it is treated.

According to the Centre of Disease Control and Prevention, about 97% of babies born with non-critical heart conditions are expected to survive one year of age, and 95% are expected to survive up to 18 years of age.

About 75% of babies with critical heart issues are expected to survive the first year and 69% up to 18 years of age.

What are the prevention tips for congenital heart defects?

It may be impossible to prevent congenital heart defects as the exact causes are unknown. However, here some tips that you can follow to help reduce the risk:

  • Attend regular prenatal check-ups with your doctor during pregnancy
  • Consume supplements containing folic acid
  • Do not drink or smoke (even second-hand smoke)
  • Protect yourself against rubella infection (German measles) through vaccination
  • Control your blood sugar level
  • Manage chronic health conditions e.g., phenylketonuria
  • Avoid harmful substances e.g., strong-smelling paint or cleaning products
  • Check with your doctor or pharmacist before consuming any medications


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