Causes

How the heart works

To understand the causes of congenital heart defects, it may be helpful to know how the heart works.

The heart is divided into four hollow chambers, two on the right and two on the left. To pump blood throughout the body, the heart uses its left and right sides for different tasks.

The right side of the heart moves blood to the lungs through the lung (pulmonary) arteries. In the lungs, blood picks up oxygen then returns to the heart's left side through the pulmonary veins. The left side of the heart then pumps the blood through the body's main artery (aorta) and out to the rest of the body.