Common Types of Congenital Heart Defects

Congenital heart disease can be broadly classified into two main categories based on cardiovascular malformations, the direction of blood shunting in the heart, and whether or not the lips and nails appear cyanotic. The first group is non-cyanotic congenital heart disease, which typically involves milder conditions. The second type is cyanotic congenital heart disease, which is often associated with more complex cardiovascular abnormalities.

Understanding Non-Cyanotic Congenital Heart Defects

Non-cyanotic congenital heart defects usually involve a left-to-right shunt, where blood flows from the left atrium or left ventricle through an internal cardiac defect into the right atrium or right ventricle. As the condition progresses, it can lead to increased pressure in the pulmonary artery. This elevated pressure affects the entire right side of the heart, including the right atrium and right ventricle. When the pressure on the right side of the heart exceeds that on the left, deoxygenated venous blood may begin to flow back into the left side of the heart.

Potential Complications of Non-Cyanotic Defects

Once this reversed flow occurs, the unoxygenated blood from the right side of the heart enters the left atrium and left ventricle before being pumped out to the rest of the body. This abnormal circulation can lead to cyanosis—a bluish discoloration of the skin, lips, and nails due to low oxygen levels in the blood. When cyanosis develops in previously non-cyanotic heart defects, it often indicates a worsening of the condition and can lead to serious health consequences if not treated promptly.

Characteristics of Cyanotic Congenital Heart Defects

Cyanotic congenital heart disease is typically associated with structural abnormalities that result in reduced oxygen levels in the blood reaching the body. These defects often involve complex malformations such as tetralogy of Fallot, transposition of the great arteries, or truncus arteriosus. Patients with cyanotic heart disease commonly present with noticeable bluish skin tone from birth or early infancy due to the persistent lack of adequate oxygenation in their bloodstream.