The Most Common Types of Congenital Heart Defects

Congenital heart disease refers to structural abnormalities in the heart that develop before birth. These defects can affect the heart's walls, valves, or blood vessels, and vary in severity. Among the many types, some are more frequently diagnosed than others.

Atrial Septal Defect (ASD)

One of the most commonly diagnosed congenital heart conditions is atrial septal defect. In a healthy heart, the wall between the two upper chambers (atria) is fully closed, preventing blood from mixing. However, in ASD, a small hole remains open in the septum, allowing blood to flow between the left and right atria. A specific and milder form of this defect is known as patent foramen ovale (PFO), which occurs when a small flap-like opening in the atrial septum fails to close completely after birth. While PFO is a type of ASD, it differs from more serious forms of septal defects.

Ventricular Septal Defect (VSD)

Another prevalent congenital heart condition is ventricular septal defect. This occurs when there is an opening in the wall (septum) separating the two lower chambers of the heart (ventricles). As a result, oxygen-rich blood from the left ventricle flows back into the right ventricle, increasing blood flow to the lungs. This can lead to symptoms such as shortness of breath, fatigue, and poor growth in infants if left untreated.

Patent Ductus Arteriosus (PDA)

Before birth, a fetal blood vessel called the ductus arteriosus connects the pulmonary artery and the aorta, allowing blood to bypass the lungs. Normally, this vessel closes shortly after birth. If it remains open, the condition is called patent ductus arteriosus. This results in abnormal blood flow between the two major blood vessels of the heart, which can cause heart enlargement and high blood pressure in the lungs if not addressed early.

Tetralogy of Fallot

Tetralogy of Fallot is a more complex and rare congenital heart defect that involves a combination of four related heart abnormalities: a ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta. This combination disrupts normal blood flow and often results in low oxygen levels in the blood, causing a bluish tint to the skin (cyanosis). Treatment typically involves surgical correction early in life and requires long-term follow-up care.