What is mitral regurgitation (MR)?

Mitral regurgitation involves blood leaking back into the left top chamber, through the mitral valve. 

The mitral valve separates the left atrium from the left ventricle and regulates the flow of blood between these two chambers. In mitral valve regurgitation, the mitral valve leaks, allowing the backflow of blood through the heart and into the lungs. This condition can cause shortness of breath, irregular heartbeats and pain.

The mitral valve separates the left upper chamber (atrium) from the left lower chamber (ventricle) of the heart. The heart has two cycles: systole and diastole. During diastole the left ventricle fills with blood which will empty it during the systole to the body (circulation). During diastole mitral valve is open in order to allow the filling of the ventricle with blood and during systole it is closed to forbid the return of blood to the left atrium. If the mitral valve loses its ability to be completely closed during systole or it is perforated (from an infection) then mitral regurgitation occurs, which means that blood returns from the ventricle to the atrium in the form of a jet.

The mitral valve controls blood flow between two of the heart’s chambers, the left atrium and the left ventricle. During mitral valve regurgitation, the valve’s flaps, or leaflets, that regulate blood flow through the valve do not close properly. This is sometimes caused by prolapse, when the leaflets flop backward into the left atrium. If this valve is not functioning correctly, the left side of the heart can become enlarged, and the left ventricle can fail.

Common medications for the treatment of mitral valve regurgitation symptoms include diuretics to reduce fluid retention in the body, anti-hypertensives to control high blood pressure, or antibiotics to prevent or treat a bacterial infection.

Your physician may recommend surgery to replace or repair the mitral valve. Valve repair consists of a number of procedures designed to tighten the valve opening, including stitching the leaflets partially together, tightening cords that connect to the leaflets, narrowing the ring around the valve or removing part of the leaflet material.

Dr. David H. Adams, MD
Cardiothoracic Surgeon

Also known as mitral incompetence or mitral insufficiency, mitral regurgitation is a valvular heart disease in which one of the heart valves fails to close properly, causing blood to leak through the opening and go in the wrong direction.

People with a history of rheumatic fever, coronary artery disease, heart attack or a hereditary disorder, such as Marfan syndrome, are at increased risk of mitral regurgitation. Degenerative mitral valve disease such as mitral valve prolapse is also a common cause for mitral regurgitation.

Dr. Douglas E. Severance, MD
Family Practitioner

Mitral regurgitation or mitral valve regurgitation means there is blood leaking backwards through your mitral valve. Like all heart valves, the mitral valve is a one-way passage. Usually, the mitral valve closes to prevent blood from flowing backward into the left atrium, or the upper left heart chamber, while the heart is ejecting blood out of the aortic valve. With mitral valve regurgitation, one of the leaflets of the valve billows backward into the left atrium. This allows some blood to flow back, or regurgitate, into the left atrium. This regurgitation happens at the time when the blood is supposed to be moving forward. When the heart valves work properly, they open and close tightly. But with mitral regurgitation, the mitral valve does not shut tightly, resulting in the blood flowing backward.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.