Congenital Heart Disease

Definition

Congenital heart disease, or congenital heart defect, includes a variety of structural problems of the heart or its major blood vessels, which are present at birth.

Description

The heart, which is completely developed about eight weeks after conception, is one of the earliest organs to completely develop. Congenital heart defects occur when the heart or blood vessels near the heart do not develop properly before birth. Some infants are born with mild types of congenital heart defects, but most need surgery in order to survive. In some cases, the defect may be mild and unnoticed at birth, then diagnosed later in life.

Research is ongoing, and at least 35 congenital heart or cardiovascular defects have been identified. Each defect is defined by its location and severity. Most congenital cardiovascular defects obstruct the flow of blood in the heart or nearby blood vessels, or cause an abnormal flow of blood through the heart. Rarer congenital cardiovascular defects occur when the newborn has only one ventricle (lower chamber), when the pulmonary artery (leading to the lungs) and the aorta (the largest artery that brings blood to the body) come out of the same ventricle, or when one side of the heart is not completely formed.

Patent ductus arteriosus

Ductus arteriosus refers to an open passageway—or temporary blood vessel (ductus)—that carries blood from the heart via the pulmonary artery to the aorta before birth. This passageway allows blood to bypass the lungs, which are not yet functional in the fetus. The ductus should close spontaneously in the first few hours after birth. When it does not close in the newborn, some of the blood that should flow through the aorta returns to the lungs. Patent ductus arteriosus is common in premature babies, but rare in full-term babies. It has been associated with mothers who had German measles (rubella) while pregnant. Patent ductus arteriosus accounts for 6–11 percent of all cases of congenital cardiovascular defects in the United States.