Heart conditions and other disorders, age-related changes, rheumatic fever, or infections can cause acquired heart valve disease. These factors change the shape or flexibility of once-normal valves.
The cause of congenital heart valve disease isn't known. It occurs before birth as the heart is forming. Congenital heart valve disease can occur alone or with other types of congenital heart defects.
Heart Conditions and Other Disorders
Certain conditions can stretch and distort the heart valves, such as:
- Damage and scar tissue due to a heart attack or injury to the heart.
- Advanced high blood pressure and heart failure. These conditions can enlarge the heart or the main arteries.
- Atherosclerosis (ath-er-o-skler-O-sis) in the aorta. Atherosclerosis is a condition in which a waxy substance called plaque (plak) builds up inside the arteries. The aorta is the main artery that carries oxygen-rich blood to the body.
Men older than 65 and women older than 75 are prone to developing calcium and other types of deposits on their heart valves. These deposits stiffen and thicken the valve flaps and limit blood flow through the valve (stenosis).
The aortic valve is especially prone to this problem. The deposits look similar to the plaque deposits seen in people who have atherosclerosis. Some of the same processes may cause both atherosclerosis and heart valve disease.
Untreated strep throat or other infections with strep bacteria that progress to rheumatic fever can cause heart valve disease.
When the body tries to fight the strep infection, one or more heart valves may be damaged or scarred in the process. The aortic and mitral valves most often are affected. Symptoms of heart valve damage often don't appear until many years after recovery from rheumatic fever.
Today, most people who have strep infections are treated with antibiotics before rheumatic fever occurs. If you have strep throat, take all of the antibiotics your doctor prescribes, even if you feel better before the medicine is gone.
Heart valve disease caused by rheumatic fever mainly affects older adults who had strep infections before antibiotics were available. It also affects people from developing countries, where rheumatic fever is more common.
Common germs that enter the bloodstream and get carried to the heart can sometimes infect the inner surface of the heart, including the heart valves. This rare but serious infection is called infective endocarditis (EN-do-kar-DI-tis), or IE.
The germs can enter the bloodstream through needles, syringes, or other medical devices and through breaks in the skin or gums. Often, the body's defenses fight off the germs and no infection occurs. Sometimes these defenses fail, which leads to IE.
IE can develop in people who already have abnormal blood flow through a heart valve as the result of congenital or acquired heart valve disease. The abnormal blood flow causes blood clots to form on the surface of the valve. The blood clots make it easier for germs to attach to and infect the valve.
IE can worsen existing heart valve disease.
Other Conditions and Factors Linked To Heart Valve Disease
Many other conditions and factors are linked to heart valve disease. However, the role they play in causing heart valve disease often isn't clear.
- Autoimmune disorders. Autoimmune disorders, such as lupus, can affect the aortic and mitral valves.
- Carcinoid syndrome. Tumors in the digestive tract that spread to the liver or lymph nodes can affect the tricuspid and pulmonary valves.
- Metabolic disorders. Relatively uncommon diseases (such as Fabry disease) and other metabolic disorders (such as high blood cholesterol) can affect the heart valves.
- Diet medicines. The use of fenfluramine and phentermine ("fen-phen") has sometimes been linked to heart valve problems. These problems typically stabilize or improve after the medicine is stopped.
- Radiation therapy. Radiation therapy to the chest area can cause heart valve disease. This therapy is used to treat cancer. Heart valve disease due to radiation therapy may not cause symptoms until years after the therapy.
- Marfan syndrome. Congenital disorders, such as Marfan syndrome and other connective tissue disorders, can affect the heart valves.