Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Heart Disease Health Center

Font Size

Mitral Valve Regurgitation - Cause

There are two forms of mitral valve regurgitation (MR): chronic and acute. Chronic mitral valve regurgitation develops slowly over several years. Acute MR develops suddenly.

Chronic mitral valve regurgitation

There are two types of chronic mitral valve regurgitation: primary and secondary.

Primary means there is a problem with the anatomy of the valve. The valve does not work well and does not close tightly.

Primary regurgitation can be caused by:

  • Calcium buildup as a person ages. The mitral valve may become hard, or calcified, around the tough ring of tissue (annulus) to which the mitral valve flaps are attached. Normally the mitral annulus is soft and flexible. But as a person ages, calcium may build up inside the annulus. This hardened mitral valve cannot close completely, and blood leaks backward (regurgitates) into the upper left chamber of the heart camera.gif (atrium).
  • Mitral valve prolapse.
  • Heart defects or abnormalities present at birth (congenital heart defects).
  • Endocarditis, which is an infection of the lining of the heart and heart valves. This infection can scar the mitral valve.
  • Autoimmune diseases that can damage the mitral valve, such as rheumatoid arthritis or lupus.
  • Marfan's syndrome, which is a connective tissue disease.
  • Rheumatic fever, which can scar the heart valves. This can prevent them from closing completely.
  • Previous use of the weight-loss medicine fen-phen (phentermine and fenfluramine/dexfenfluramine), which appears to increase the risk of heart valve disease.
  • Injury to the heart or the chordae tendineae, which are strong, flexible cords that control the opening and closing of the mitral valve.

Secondary means another heart problem is causing the valve to not close tightly. The anatomy of the valve is typically normal. The heart problem affects the heart muscle, and this causes regurgitation.

Secondary regurgitation can be caused by heart problems that affect the left ventricle. These problems include:

Acute mitral valve regurgitation

Acute mitral valve regurgitation occurs when the mitral valve or one of its supporting structures ruptures suddenly, creating an immediate overload of blood volume and pressure in the left side of the heart. Your heart doesn't have time to adjust to the increased volume and pressure of blood (as it does in chronic MR).

Causes of sudden rupture include:

  • Injury to the chordae tendineae. Endocarditis may also cause the chordae tendineae to rupture.
  • Injury to the chest.
  • Heart attack, which may cause the rupture of the muscle (papillary) surrounding the valve.
  • Problems with a prosthetic mitral valve.
  • Perforation of the mitral valve flap (leaflet), caused by endocarditis.

    WebMD Medical Reference from Healthwise

    Last Updated: August 08, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
    Next Article:

    Today on WebMD

    x-ray of human heart
    A visual guide.
    atrial fibrillation
    Symptoms and causes.
    heart rate graph
    10 things to never do.
    heart rate
    Get the facts.
    empty football helmet
    red wine
    eating blueberries
    Simple Steps to Lower Cholesterol
    Inside A Heart Attack
    Omega 3 Sources
    Salt Shockers
    lowering blood pressure