Who Is At Risk for Heart Block?

The risk factors for congenital and acquired heart block are different.

Congenital Heart Block

If a pregnant woman has an autoimmune disease, such as lupus, her fetus is at risk for heart block.

Autoimmune diseases can cause the body to make proteins called antibodies that can cross the placenta. (The placenta is the organ that attaches the umbilical cord to the mother's womb.) These antibodies may damage the baby's heart and lead to congenital heart block.

Congenital heart defects (problems with the heart's structure) also may result in congenital heart block. Most of the time, doctors don't know what causes these defects.

Heredity may play a role in certain heart defects. For example, a parent who has a congenital heart defect may be more likely than other people to have a child with the condition.

Acquired Heart Block

Acquired heart block can occur in people of any age. However, most types of the disorder are more common in older people. This is because many of the risk factors are more common in older people.

People who have a history of heart disease or heart attacks are more likely to have heart block. Examples of heart disease that can lead to heart block include heart failure, coronary artery disease, and cardiomyopathy.

Other diseases also may raise the risk for heart block. These include sarcoidosis and the degenerative muscle disorders, Lev's disease and Lenegre's disease.

Exposure to toxic substances or taking certain medicines, such as digitalis, can raise your risk for heart block.

Well-trained athletes and young people are at higher risk for first-degree heart block caused by an overly active vagus nerve. Activity in this nerve slows the heart rate.