What is the aortic valve?

The location of the aortic valve is shown in the diagram to the right. The heart has two sets of pumping chambers: the right-sided chambers pump blood to the lungs, and the left side pumps blood to the rest of the body. The left side, therefore, has a harder job than the right side, and the left side does most of the work. The main pumping chambers of the heart are called the ventricles.

Because the ventricle is a pump, it must have both an inflow valve and an outflow valve. The aortic valve is on the left side of the heart and is the outflow valve. The aortic valve opens to allow blood to leave the left ventricle (the main pumping chamber of the heart) and closes to prevent blood from leaking backwards into the ventricle from the rest of the body.

What causes an aortic valve to malfunction?

The aortic valve to malfunction for several reasons:

• It may be abnormal from birth (congenital aortic valve disease)
• It may become diseased with age (acquired aortic valve disease)

Normal aortic valve  Bicuspid aortic valve

Congenital aortic valve disease

The most common congenital abnormality is a bicuspid aortic valve. As shown below, the aortic valve normally has three leaflets, but a bicuspid aortic valve has only two. It may, therefore, not open or close completely.

A bicuspid aortic valve is a common abnormality and occurs in 1-2% of people. This is the second most common cause of aortic valve disease requiring surgery. Such valves may function normally for years before becoming stenotic (blocked), regurgitant (leaky), or both. People with a bicuspid aortic valve require antibiotic prophylaxis before dental procedures but generally no other special precautions are required other than regular follow up with a qualified cardiologist.

Acquired aortic valve disease

The most common cause of aortic valve disease requiring surgery is called "senile aortic calcification," meaning that the valve has worn out with age. When a valve becomes worn, the body deposits calcium on it for reasons that are unknown. The calcium restricts or limits the motion of the valve leaflets. This may prevent the valve from opening (causing stenosis) or closing (causing leakage or regurgitation).

 Less common causes of aortic valve disease include diseases of the aorta, the main blood vessel coming out of the heart and carrying blood to the rest of the body, including ascending aortic aneurysms, aortic dissection, and Marfan's syndrome.

What are the warning signs of a failing aortic valve?

A failing aortic valve may cause a variety of symptoms including:

• Shortness of breath,
• Chest pain (angina pectoris),
• Dizziness or loss of consciousness (passing out)

A narrow valve makes the heart work harder just to pump the blood through the valve to the body. A leaky valve lets blood back into the heart after it has been pumped out. The heart must therefore pump more blood forward to make up for the blood that is leaking backwards.

Either way the extra work may cause symptoms of heart failure, such as shortness of breath. Early on the shortness of breath may be noticeable only with exercise. Later, with the progression of valve disease, a patient could experience shortness of breath with even light activity or at rest. Some patients will be unable to sleep flat in bed or may awaken from sleep short of breath. Another sign of heart failure that may occasionally occur is swelling of your feet, particularly prominent later in the afternoon or evening although other conditions, such as varicose veins, can also cause this to occur.

The extra work the heart has to perform may also cause chest pain or angina pectoris similar to the symptoms of a heart attack. It may be difficult to tell the difference between heart valve disease and narrowing of the blood vessels to the heart itself.

Aortic valve disease may also cause dizziness, light headedness or even fainting spells.

How is Aortic Valve Diseases corrected?

• Aortic valve surgery is performed when an abnormality of the valve compromises the normal functioning of the valve.

Other aortic valve abnormalities, congenital as well as aquired (for example rheumatic, infection radiation), occur but are less common. Many times, patients with congenital or bicuspid aortic valve disease do not require aortic valve surgery until they are adults.

To learn more about aortic valve surgery, click here