Understanding Congenital Heart Defects

Congenital Heart Defects

by Stefanie Zinchiak M.Ed.
Medically Reviewed by Dr. Linda Lemay M.D.

Understanding Congenital Heart Defects

Congenital Heart Defects

Congenital heart defects are problems with the structure of the heart and are present at birth. In fact, congenital heart defects are the most common type of birth defect, occurring in the heart’s chambers, valves or blood vessels. These structural defects affect the normal flow of blood through the heart. And while many defects are mild and may require little or no medical treatment, others can be life threatening. Approximately 8 out of 1,000 newborns are born with a heart defect and more than 1 million adults are living with congenital heart defects.

There are many congenital heart defects, some of which are ‘simple’ and some of which are more complex, involving multiple defects. Based on the diagnosis, ask your health care provider for more information to better understand and learn about the condition. Here are just a few of the more common types of congenital heart defects.

Types of Congenital Heart Defects

Septal Defects: Also referred to as having a  ‘hole in the heart’, a septal defect is when there is a hole in the heart’s wall that separates the chambers on the left and right side of the heart. This allows the blood to mix between the two sides of the heart. The holes can be small, medium or large, and often times with a small hole they don’t affect the heart’s function and require no treatment. These smaller holes will likely close on their own as the heart grows. The medium and larger holes that require treatment can be repaired using a catheter procedure or open-heart surgery. There are 2 types of septal defects:

Types of Congenital Heart Defects

Atrial Septal Defect (ASD): This is a hole in the part of the septum (heart’s wall), which separates the upper chambers of the heart, known as the atria. This allows the oxygen-rich blood from the left atrium to flow into the right atrium.

Ventricular Septal Defect (VSD): This is a hole in the part of the septum (heart’s wall), which separates the lower chambers of the heart, known as the ventricles. This allows the oxygen-rich blood to flow from the left ventricle into the right ventricle, instead of into the aorta and out to the body.

Patent Ductus Arteriosus (PDA): During pregnancy, a blood vessel called the ductus arteriosus allows blood flow between the aorta and pulmonary artery. However, shortly after birth this vessel closes. When this process fails to take place and remains open (patent), it allows the oxygen-rich blood to mix with oxygen-poor blood, straining the heart. A heart murmur may be the only sign of PDA. PDA is treated with medicine, catheter procedures and surgery, but many small PDAs often close without treatment.

Narrowed Valves: Heart valves control the flow of blood from the atria (upper chambers) to the ventricles (lower chambers), and from the ventricles to the arteries.  There are various structural defects but the most common is pulmonary valve stenosis, which is a narrowing of the pulmonary valve and can range from being mild to severe. Mild cases typically don’t require treatment.

Tetralogy of Fallot: This is the most common complex heart defect, and it is a combination of 4 defects. With this condition, not enough blood is able to reach the lungs to get oxygen, and oxygen-poor blood flows to the body. The treatment involves open-heart surgery and requires lifelong monitoring to ensure optimal health.

Tetralogy of Fallot

Signs & Symptoms

Many congenital heart defects cause few or no signs and symptoms, but some severe defects can cause symptoms such as rapid breathing, cyanosis (bluish tint to the skin, lips, and fingernails), fatigue and poor blood circulation. Heart defects can also cause heart murmurs, which is an extra or unusual sound heard during a heartbeat. However, it’s important to note than many healthy children have heart murmurs as well. 


Severe congenital heart defects are generally diagnosed during pregnancy or soon after birth. Less severe defects may not be diagnosed until children are older. For diagnosis, the doctor will likely perform a physical exam (listening to the child’s heart and lungs and looking for signs such as cyanosis). Diagnostic tests may include an echocardiography, which is a painless test that uses sound waves to create a moving picture of the heart, or an EKG, which is also a painless test and records the heart’s electrical activity to show the heartbeat and rhythm.

Other diagnostic tests may include a chest x-ray, pulse oximetry or cardiac catheterization. With cardiac catheterization, a thin flexible tube called a catheter is put into a vein in the arm, groin or neck and goes to the heart, which then allows for dye to be injected and for the doctor to see blood flowing on an x-ray image. This same type of procedure using a catheter can be used to repair some heart defects.

Where to Go

Children need health care designed specifically to meet their needs. "We found in our studies that 75% percent of women associate children’s hospitals with care for seriously ill children and nearly 50% of women are unfamiliar with the offerings of a children’s hospital. Our goal at the Women’s Choice Award is to help moms—and parents—make educated, confident decisions about where to take their children for a wide range of healthcare services.” said Delia Passi, CEO and founder of the Women’s Choice Award. The following hospitals have met the highest standards for Pediatric Care and have made the list of Best Children's Hospitals by the Women’s Choice Award, America's trusted referral source for the best in healthcare.

Questions to Ask Your Doctor:

Q: How severe is the defect and what type of treatment is required?

Q: If no treatment is required: How will my child be monitored to ensure everything progresses normally?

Q: Are there any signs or symptoms that should alert me to seek immediate medical attention?

Q: Can you refer me to a Pediatric Cardiologist so that I can have my child monitored, if needed?


America’s Best Children’s Hospitals
American’s Best Hospitals for Obstetrics
The American Heart Association
Know Where to Go, Know What to Do

This content is for informational purposes only and is not intended to provide medical advice or to treat, diagnose, cure or prevent any disease or condition.  Always seek the advice of your healthcare provider.