Definition

The flow of blood pumped by the heart is controlled by one-way valves. These valves assure that blood moves in only one direction. Mitral regurgitation occurs when the heart’s mitral valve leaks blood into the upper chamber from the lower chamber.

If the amount of blood that leaks is severe, mitral regurgitation can be serious. The sooner it is treated, the better the outcome.

Causes

Mitral regurgitation may be caused by:

• Mitral valve prolapse—Abnormal closure of the valve with protrusion of a leaflet tip backward into the left atrium, causing it to leak.
• Infections that cause scarring of the heart valve, such as rheumatic fever or bacterial endocarditis.
• Damage from a heart attack.
• Several different types of congenital heart defects, which can affect mitral valve function.
• Cardiomyopathies—Diseases that weaken the heart muscle and stretch the mitral valve.

Risk Factors

Factors that may increase your chance of developing mitral regurgitation include:

• A history of rheumatic fever or other serious infectious disease
• Autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis
• Storage diseases such as hemochromatosis and glycogen storage disease
• Cardiovascular disease
• Muscle disease
• Malnutrition
• Alcoholism
• Radiation exposure
• Exposure to certain drugs such as lithium, sulfonamides, cancer chemotherapy, and phenothiazines

Symptoms

The speed with which symptoms progress closely follow the cause of mitral disease. Acute diseases cause rapid decline, while more chronic diseases lead to slower onset of symptoms.

Mitral regurgitation may cause:

• Chronic, progressive fatigue
• Shortness of breath, especially with exertion
• Worsening shortness of breath when you lie down
• New, associated palpitations or racing heart rate, which may suggest the development of a heart arrhythmia

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. Leaking heart valves usually make sounds called murmurs that can be heard through a stethoscope. You will likely be referred to a cardiologist.

Imaging tests evaluate the heart and surrounding structures. These can be done with:

• Chest x-ray
• Echocardiogram
• Cardiac catheterization

An electrocardiogram (EKG) can measure your heart’s electrical activity.

Treatment

Treatment options depend on the severity and history of the valve leakage and its effects on the heart’s size and function. Talk with your doctor about the best treatment plan for you. Treatment options include the following:

Prevention

To help reduce your chance of getting mitral regurgitation:

• Prevent cardiovascular disease by controlling weight and blood pressure, exercising, eating heart-healthy foods, and watching your cholesterol levels
• Avoid contact with streptococcal diseases including strep throat, pharyngitis, and scarlet fever
• Get prompt treatment for infections
• Avoid IV drug use
• Limit alcohol intake

National Heart, Lung, and Blood Institute http://www.nhlbi.nih.gov

Heart and Stroke Foundation of Canada http://www.heartandstroke.ca

Mitral regurgitation. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated April 2, 2014. Accessed August 20, 2014.

Shipton B and Wahba H. Valvular heart disease: review and update. Am Fam Physician. 2001;63:2201-2208.

Wood AJJ. Adverse reactions to drugs. In: Isselbacher K, et al. (Eds.) Harrison’s Principles of Internal Medicine. 14th ed. New York: McGraw-Hill; 1998.

Wynne J, Braunwald E. The cardiomyopathies and myocarditides. In: Isselbacher K, et al. (Eds). Harrison’s Principles of Internal Medicinem. 14th ed. New York: McGraw-Hill; 1998.