Leakage of blood back through the aortic valve of the heart
The aortic valve separates the left lower chamber of the heart (the left ventricle) from the aorta, which is the main artery leading from the heart. This valve normally stops blood from flowing back into the heart from the aorta. In aortic incompetence, the valve cusps (flaps) do not close tightly, letting blood leak back from the aorta. As a result, the heart has to pump harder and faster to circulate blood around the body, and this may eventually lead to the development of chronic heart failure.
About 1 in 50 boys and 1 in 100 girls are born with an aortic valve with two cusps instead of the normal three. Another cause of aortic incompetence is the rare genetic disorder Marfan’s syndrome. A possible cause of valve damage later in life is infection (see Infective endocarditis). Sometimes, long-standing high blood pressure (see Hypertension) can cause the root of the aorta to stretch so that the cusps of the aortic valve do not close tightly and the valve leaks. The aortic valve flaps may also become leaky as a result of the rare inflammatory joint disorder ankylosing spondylitis. Other causes of aortic incompetence include rheumatic fever and syphilis, but these diseases are now rare in developed countries due to the widespread use of effective antibiotics.
If aortic incompetence is mild, it may not cause symptoms for years. If symptoms do develop, they may include:
Shortness of breath during exertion.
Awareness of the heart beating strongly.
In severe aortic incompetence, heart failure may eventually develop, leading to symptoms such as constant shortness of breath and swollen ankles.
If there are no symptoms, aortic incompetence is usually discovered during a routine examination. Your doctor may then arrange for electrocardiography (see ECG) to evaluate the electrical activity of the heart. In addition, the heart may be imaged by echocardiography, which looks at the interior of the heart and can evaluate the movement of the valves. A chest X-ray may also be taken to see if the heart has enlarged.
If the aortic incompetence is mild, often no treatment is needed. However, if you have symptoms or if chronic heart failure develops, you may need treatment with drugs such as ACE inhibitors, which reduce the work that the heart has to do.
You may also be evaluated to see whether surgery to repair or replace the defective valve will help (see Heart valve replacement). In some cases, valve replacement surgery may be recommended if tests show that the valve is leaking severely and the heart has started to enlarge, even though there may be no external symptoms or signs of heart failure. In all cases where surgery is performed, it is likely to be more successful if it is done before heart failure becomes advanced.
An abnormal or replacement aortic valve is more susceptible to infection (see Infective endocarditis) than a normal valve. Your doctor will advise you to maintain good oral hygiene to reduce the risk of infection. You will also be told how to recognize symptoms of infective endocarditis so that treatment can be given promptly if it does develop.
Once the damaged aortic valve has been repaired or replaced, the outlook for the affected person is good and life expectancy should be normal.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.