Your blood is supposed to follow a one-way path through your heart. It flows in through the top chamber (the left atrium), down to the bottom chamber (the left ventricle), and then out to your body. Your mitral valve separates these two chambers and keeps the blood from flowing backward. 

In mitral valve regurgitation, your mitral valve does not work as it should and allows blood to flow backward into your upper heart chamber.

Mitral valve regurgitation can happen suddenly (acute) or, more commonly, gradually over time (chronic). Acute mitral valve regurgitation is often caused by damage to the heart, perhaps from a heart attack or a heart infection called endocarditis.

There are many possible reasons you can develop chronic mitral valve regurgitation, including mitral valve prolapse, rheumatic heart disease and untreated high blood pressure.

If you have mitral valve regurgitation, you may notice that you feel very tired and that you have a hard time catching your breath when you exercise or when you are lying down. You may also notice swelling in your legs.

Treatment will depend on the type and severity of your condition and may include medications or surgery. Use this condition center to learn more, create a list of questions to ask your health care provider and get practical tips.

Overview

The mitral valve separates the left top chamber (atrium) and the left bottom chamber (ventricle) of the heart. It has two very thin flaps called leaflets. Normally, when the leaflets open, blood pumps through. When the leaflets close, they prevent blood from flowing backward.

If your mitral valve does not work correctly, you may have mitral regurgitation, also called mitral valve insufficiency. This means that the valve does not close tightly, and some blood flows backward from the left ventricle to the left atrium. When this happens, your heart must work harder to pump that extra blood.

You may not even notice your heart has a small leak, but it can get worse over time. This is known as chronic mitral regurgitation. Larger leaks can cause the heart to weaken, and people usually begin to notice symptoms such as:

• Being short of breath
• Feeling fatigued or tired when doing their usual activities
• Holding on to fluid in their ankles and feet

The leaking can also occur suddenly (for example after a heart attack). This is called acute mitral regurgitation and is an emergency.

Your health care provider may be able to discover the regurgitation by listening to your chest with a stethoscope and hearing a sound called a murmur, which should prompt further testing.