The human heart is a highly efficient pump with four chambers – two upper (the atria) and two lower (the ventricles). Each of those chambers is closed off by a one-way valve. As the heart expands and contracts 100,000 times a day, the four valves open and close in sequence to keep the blood flowing the right way.
The four heart valves are:
- The tricuspid valve, which regulates blood flow between the right atrium and right ventricle
- The pulmonary valve, regulating blood flow from the right ventricle into the pulmonary arteries
- The mitral valve, which controls the flow of oxygen-rich blood from the left atrium into the left ventricle
- The aortic valve, which is the final doorway from the left ventricle into the aorta, the body’s main artery
To work correctly and keep blood flowing smoothly, the valves’ flap-like doors or leaflets must open at the right time in response to a pressure change, then close securely to prevent blood from back flowing. In heart valve disease, the flaps either cannot open sufficiently or close securely.
- For more information: Your heart valves
Women and Heart Valve Disease
Rheumatic fever in childhood used to be the major cause of valve disease in women. Today, rheumatic fever is rare in developed countries, and calcification of the valve or a weakening of the valve tissue with aging are now the most common causes of valve disease. A narrowed mitral valve or a deformed aortic valve also may be a congenital defect (present at birth). Other causes of valve dysfunction include an infection in the lining of the heart's walls and valves and heart disease such as coronary artery disease or heart attack.
Most of the more than 100.000 heart valve repair operations performed in the United States every year are on the mitral and aortic valves, so we will focus on the problems that can occur with those two valves.
Mitral Valve Disease
MVP is the most common forms of valve disease, affecting 6 percent of all women. In this condition one or both of the valve leaflets is enlarged or floppy, preventing the valve from closing evenly. When the valve shuts, the leaflets bulge into the left atrium. You may have heard mitral valve prolapse referred to as click-murmur syndrome from the sound the valve makes when it closes.
Although men and women are affected by MVP in equal numbers, the course of the disease differs by gender. MVP is a fairly common diagnosis in young women, but the incidence decreases among elderly women. For men, the incidence of MVP remains fairly steady across age groups. Men with MVP are more likely than women to require surgical treatment, and the need for surgery increases with age. Overall, 60 percent of people with MVP will not require treatment.
MVP may coexist with coronary artery disease, congestive or hypertrophic cardiomyopathy, atrial septal defect, Marfan syndrome or other connective tissue disorders. But most women with MVP do not have any of these other medical problems, and their MVP is considered idiopathic.
- For more information: mitral valve prolapse
Mitral stenosis is a narrowing or blockage of the mitral valve, which causes blood to back flow into the left atrium instead of flowing down into the left ventricle. Rheumatic fever is the major cause of mitral stenosis. Other causes are infective endocarditis, severe calcification of the valve opening, tumors, systemic lupus erythematosus or cancer.
Three times more women than men have mitral valve stenosis, and women account for 70 percent of all cases. In women, the valve tends to calcify at a later age than in men.
Aortic Valve Disease
Prolapse and stenosis also can occur in the aortic valve. For reasons that are not yet clearly understood, aortic valve prolapse is more common in men than in women.
Aortic Valve Prolapse
Severe, uncontrolled high blood pressure has been associated with aortic valve prolapse. Another cause is a congenital defect in which the valve has only two leaflets instead of the usual three, a condition affecting men more often than women. This deformity also can cause aortic valve stenosis
Calcification is the most common cause of aortic stenosis in elderly patients. This condition affects men and women equally and accounts for the majority of aortic valve disease today. About 25 percent of men and women over age 65 have mild thickening and/or calcification of a tri-leaflet aortic valve but without restriction of valve movement - this is termed aortic sclerosis. Aortic sclerosis is usually not progressive and requires no specific treatment. However, aortic stenosis affects approximately 2 to 3 percent of people over age 75 and frequently requires surgical correction.
- For more information: types of heart valve disease