The aortic valve controls blood flow from the left ventricle to the aorta and the rest of the body. It opens when the ventricle contracts and closes when the ventricle relaxes.
Aortic stenosis means that the aortic valve has become narrowed. The result is that the left ventricle must squeeze harder to get a sufficient amount of blood through the aortic valve with each beat. (Imagine trying to push the same amount of water through a small syringe needle as through a hose). The increased work load makes the muscle of the left ventricle grow thicker (hypertrophy). Eventually the heart muscle cannot keep up with the work load and begins to fail.
The three major causes of aortic stenosis are calcific degeneration or deposits of calcium on the valve (primarily affects the elderly), congenital abnormality with only two instead of three cusps, and rheumatic fever. Even in the case of a congenital defect, symptoms are most likely to occur only in adulthood.
Aortic stenosis can occur at any age (because the causes are different) but is usually asymptomatic until middle or old age.
The condition is three times more common in men than women.
Aortic stenosis does not always cause symptoms immediately, even though the valve can be tight. When the heart begins to fail, symptoms of congestive heart failure can develop including fatigue, weakness, shortness of breath with exercise or at night, and swelling in the ankles.
Characteristic signs include a heart murmur heard with a stethoscope.
Diagnosis is based on the medical history including symptoms and the physical examination. Further studies may include an electrocardiogram (EKG), chest X-ray, echocardiogram (ultrasound study of the heart), and cardiac catheterization.
Medications cannot slow or reverse the scarring and calcification process that leads to aortic valve stenosis. Nevertheless, patients with the disease should take antibiotics before dental and other medical procedures to prevent bacterial endocarditis. Some patients may require medications to control arrhythmias (heart beat irregularities) such as atrial fibrillation.
The most important medical advice for people with mild to moderate aortic stenosis is to carefully discuss and review with their doctors any changes in symptoms. Patients with moderate aortic stenosis should have their condition checked every 6 to12 months.
Once symptoms develop, the only effective treatment for adults is surgical replacement of the aortic valve. Without surgery, people with symptoms from severe aortic stenosis usually will live for no more than a few years.
After surgery, most patients experience a marked improvement in their symptoms for many years, but surgery is not without risks or complications.
Balloon valvuloplasty is usually reserved for those people who are poor candidates for surgery or as an intermediate procedure to stabilize high-risk patients prior to surgery. Valve replacement is usually not indicated for patients who are asymptomatic unless they have severely narrowed valves or evidence of heart failure.