The mitral valve is one of four valves that regulate blood flow through the heart. More specifically, the mitral valve controls flow from the left upper chamber of your heart (the left atrium) to the left lower chamber (the left ventricle). In a healthy heart, once the blood flows to the left ventricle, the mitral valve seals shut so that when the left ventricle contracts, the blood is pumped out only through the aortic valve out to the body, as it should be, and cannot flow back into the left atrium.
Mitral valve regurgitation (or mitral valve insufficiency, as it is sometimes called) refers to when the flaps of the mitral valve, called leaflets, no longer seal properly in between heartbeats and allow blood to leak ‘backwards’ to the left atrium.
What Causes the Mitral Valve to Leak?
The mitral valve is a complex structure made up of the valve flaps (called leaflets). There are fibers that support those leaflets (called chordae tendineae or just chords), and papillary muscles that support the chords. Abnormalities or damage to any of these structures can cause mitral regurgitation.
The most common cause of mitral regurgitation is mitral valve prolapse, which is when part of the mitral valve slips backward into the left atrium when the left ventricle squeezes (contracts) during a heartbeat. Mitral valve prolapse does not always lead to regurgitation. In fact, many people who have mitral valve prolapse never develop severe leaking of the mitral valve.
The risk of developing a leaky mitral valve increases as we age because the valve is prone to wear and tear over time. The valve leaflets can be damaged or stretched out to the extent they don’t close properly, allowing blood to leak back into the heart
Symptoms and Signs
You can have a mitral regurgitation and never know. Over years, mitral regurgitation cause weakness in the left ventricle, leading to heart failure. Symptoms of heart failure related to mitral valve regurgitation include:
- Shortness of breath or difficulty breathing, especially with exertion or when lying down
- Swelling in the legs or feet
- Fatigue, exhaustion, weakness
- Fainting (syncope)
Your doctor may suspect you have mitral regurgitation after hearing a heart murmur during an examination and may want to do further testing. It is likely you will also be referred to a cardiologist. Echocardiography, and possibly cardiac magnetic resonance imaging, are the two most common ways to diagnose mitral regurgitation. These non-invasive tests can also be used to monitor your valve and the degree of any dysfunction.
Progression and Possible Complications
Patients with mitral regurgitation rarely have symptoms until the valve is leaking severely, and even then, many remain asymptomatic. Often asymptomatic patients with mild leakage remain stable for many years and need no treatment. However, because mitral regurgitation can lead to a more serious disorders, your physicians may recommend early treatment for your mitral regurgitation before symptoms develop.
Two conditions commonly related to mitral regurgitation are atrial fibrillation and heart failure, both of which can be serious. Early treatment of your mitral regurgitation may be recommended, not because you are having symptoms, but to avoid these serious complications. Also, there have been studies that indicate that early mitral valve repair (before symptoms appear or damage has occurred) is associated with better health over the long term.
Treatment for mitral regurgitation includes medical therapy, surgical intervention and recently some less invasive techniques. Once a patient is symptomatic, repair of the valve is generally recommended. There are also newer, less-invasive treatment options that involve using a catheter-based procedure to repair or replace the mitral valve. For details on treatment of mitral regurgitation, click here