The cause of most congenital heart defects is unknown.
Transposition of the great vessels is a cyanotic heart defect. This means there is decreased oxygen in the blood that is pumped from the heart to the rest of the body. Low blood oxygen leads to cyanosis (a bluish-purple color to the skin) and shortness of breath. In normal hearts, blood that returns from the body goes through the right side of the heart and pulmonary artery to the lungs to get oxygen. The blood then comes back to the left side of the heart and travels out the aorta to the body. In transposition of the great vessels, the blood goes to the lungs, picks up oxygen, and then goes right back to the lungs without ever going to the body. Blood from the body returns to the heart and goes back to the body without ever picking up oxygen in the lungs. Symptoms appear at birth or very soon afterward. How bad the symptoms are depends on the type and size of heart defects (such as atrial septal defect or patent ductus arteriosus) and how much oxygen moves through the body's general blood flow.
The condition is the second most common cyanotic heart defect.
What causes Transposition of the great vessels?
The cause of most congenital heart defects is unknown.
Transposition of the great vessels is a cyanotic heart defect. This means there is decreased oxygen in the blood that is pumped from the heart to the rest of the body. Low blood oxygen leads to cyanosis (a bluish-purple color to the skin) and shortness of breath. In normal hearts, blood that returns from the body goes through the right side of the heart and pulmonary artery to the lungs to get oxygen. The blood then comes back to the left side of the heart and travels out the aorta to the body. In transposition of the great vessels, the blood goes to the lungs, picks up oxygen, and then goes right back to the lungs without ever going to the body. Blood from the body returns to the heart and goes back to the body without ever picking up oxygen in the lungs. Symptoms appear at birth or very soon afterward. How bad the symptoms are depends on the type and size of heart defects (such as atrial septal defect or patent ductus arteriosus) and how much oxygen moves through the body's general blood flow.
The condition is the second most common cyanotic heart defect.