Heart valve disease is the term used for a number of conditions that affect the four valves of the heart. The best way to understand heart valve disease is to first understand how the heart works.

How does the heart pump blood?

Your heart is divided into two separate pumping systems-right and left:

• The right side of your heart receives oxygen-poor blood from your veins and pumps it to your lungs to take up fresh oxygen.
• The left side of your heart receives oxygen-rich blood from your lungs and pumps it through your arteries to your body.

Your heart has four separate chambers that pump blood-two on the right side and two on the left side:

• Right atrium
• Right ventricle
• Left atrium
• Left ventricle

Blood travels through your heart and lungs in four steps. In each step, it must pass through a valve.

• Step 1: The right atrium receives oxygen-poor blood from the body and pumps it through the tricuspid valve to the right ventricle.
• Step 2: The right ventricle pumps the oxygen-poor blood through the pulmonary valve to the lungs.
• Step 3: The left atrium receives oxygen-rich blood from the lungs and pumps it through the mitral valve to the left ventricle.
• Step 4: The left ventricle pumps the oxygen-rich blood through the aortic valve to the entire body.

See an illustration of the heart and its chambers, valves, and blood flow .

Disease occurs when any of the heart's valves either cannot open well enough to let blood flow through (stenosis) or cannot close well enough to prevent backflow of the blood (regurgitation). Heart valve disease can affect any of the four valves in different ways, including a combination of stenosis and regurgitation. These diseases include:

• Aortic stenosis.
• Aortic regurgitation (also know as aortic insufficiency).
• Combined aortic stenosis and regurgitation.
• Mitral stenosis.
• Mitral regurgitation.
• Combined mitral stenosis and regurgitation.
• Tricuspid stenosis.
• Tricuspid regurgitation.
• Combined tricuspid stenosis and regurgitation.
• Pulmonic stenosis.
• Pulmonic regurgitation.
• Combined pulmonic stenosis and regurgitation.

Although mitral valve prolapse does not hinder blood flow, it is often included in the list of heart valve diseases because it is seen frequently and may lead to mitral valve regurgitation.

Each of these heart valve diseases is a correctable cause of heart failure. Because of this, prompt recognition of heart valve disease may be critical. After the disease progresses, it can be more difficult to treat.