Aortic Valve Stenosis

• Aortic stenosis is narrowing of the aortic valve, impeding delivery of blood from the heart to the body.
• Aortic stenosis can be caused by congenital bicuspid aortic valve, scarred aortic valve of rheumatic fever, and wearing of aortic valve in the elderly.
• Aortic stenosis can cause chest pain, fainting, and heart failure leading to shortness of breath.
• Echocardiogram and cardiac catheterization are important tests in diagnosing and evaluating severity of aortic stenosis.
• Patients with aortic stenosis are usually given antibiotics prior to any procedures which might introduce bacteria into the bloodstream, such as dental procedures and surgeries.
• Patients with aortic stenosis who have symptoms may require surgical heart valve replacement.

Aortic stenosis is abnormal narrowing of the aortic valve. A number of conditions cause disease resulting in narrowing of the aortic valve. When the degree of narrowing becomes significant enough to impede the flow of blood from the left ventricle to the arteries, heart problems develop. The basic mechanism is as follows:

• The heart is a muscular pump with four chambers and four heart valves.
• The upper chambers, the right atrium and left atrium (atria -- plural for atrium), are thin walled filling chambers.
• Blood flows from the right and left atria across the tricuspid and mitral valves into the lower chambers (right and left ventricles).
• The right and left ventricles have thick muscular walls for pumping blood across the pulmonic and aortic valves into the circulation.
• Heart valves are thin leaflets of tissue which open and close at the proper time during each heart beat cycle.
• The main function of these heart valves is to prevent blood from flowing backwards.
• Blood circulates through the arteries to provide oxygen and other nutrients to the body, and then returns with carbon dioxide waste through the veins to the right atrium; when the ventricles relax, blood from the right atrium passes through the tricuspid valve into the right ventricle.
• When the ventricles contract, blood from the right ventricle is pumped through the pulmonic valve into the lungs to reload on oxygen and remove carbon dioxide.
• The oxygenated blood then returns to the left atrium and passes through the mitral valve into the left ventricle.
• Blood is pumped by the left ventricle across the aortic valve into the aorta and the arteries of the body.

The flow of blood to the arteries of the body is impaired when aortic stenosis exists. Ultimately, this can lead to heart failure. Aortic stenosis occurs three times more commonly in men than women.

Source: MedicineNet.com
http://www.medicinenet.com/aortic_stenosis/article.htm