Problems affecting the mitral valve

Problems with the mitral valve can make the heart less efficient at pumping blood around the body. Severe problems can lead to Heart failure (where the heart can no longer pump enough blood around the body) if the valve is not surgically repaired or replaced.

Common mitral valve problems are:

  • mitral regurgitation (also called 'mitral incompetence') where there is a backflow of blood through the valve, often as a result of a problem called mitral valve prolapse (where the valve collapses)
  • mitral stenosis where the valve doesn't open as wide as it should, restricting blood flow

These conditions can occur alone or in combination. They are covered in more detail below.

Mitral regurgitation

Mitral regurgitation means there is a backflow of blood from the left ventricle to the left atrium when the heart contracts during a heartbeat.

This can cause symptoms such as shortness of breath , tiredness, dizziness and chest pain , and it can lead to atrial fibrillation (a condition that causes an irregular and often abnormally fast heart rate), pulmonary hypertension (high pressure inside the vessels carrying blood from the heart to the lungs) and Heart failure .

Mitral regurgitation can happen when the mitral valve flaps fail to seal shut, either because of problems with the flaps (such as a mitral valve prolapse see below) or due to widening of the mitral annulus, which is the ring of muscle surrounding the valve.

These problems are more common in older people and are often the result of changes to the heart with age. For example, the mitral valve may become weaker due to 'wear and tear' or damage caused by persistent high blood pressure .

Occasionally, mitral regurgitation can occur as a result of rheumatic heart disease (a complication of rheumatic fever), cardiomyopathy (a disease of the heart muscle), endocarditis (infection of the inner lining of the heart), or congenital heart disease (birth defects affecting the normal workings of the heart).

If regurgitation is only mild, you may just be monitored at regular intervals with echocardiography (an scan of the heart) to check your heart function.

If you have moderate or severe mitral regurgitation, you'll probably need surgery to repair or replace the valve (see below). You may also need medications called nitrates or diuretics to reduce symptoms such as shortness of breath, and medication to treat atrial fibrillation .

If you have severe mitral regurgitation and you are not suitable for surgery, or you are still having problems after surgery, you may be offered medications called angiotensin-converting enzyme (ACE) inhibitors or beta-blockers to help manage the condition.

Mitral valve prolapse

Mitral valve prolapse means that one or more of the mitral flaps are floppy and don't close tightly, often leading to backflow of blood (mitral regurgitation see above).

Most people with a mitral valve prolapse will not have symptoms, unless the problem causes severe mitral regurgitation, and it is usually discovered by chance during echocardiography (an ultrasound scan of the heart) carried out for a different reason.

Occasionally, however, mitral valve prolapse can cause problems such as arrhythmia (an irregular heartbeat) and palpitations (sudden, noticeable heartbeats).

Mitral valve prolapse can be caused by problems with the connective tissues (chords) that join the mitral valve to the heart muscles or, more rarely, by damage to the heart muscles themselves as the result of a heart attack. Some people with the condition are born with it and it's more common in people with connective tissue disorders, such as Marfan syndrome .

If mitral valve prolapse isn't causing any symptoms and you are at low risk of developing severe mitral regurgitation, you won't need surgical treatment.

Mild symptoms can sometimes be controlled with lifestyle changes, such as giving up cigarettes, caffeine and alcohol, because these can cause your heart to become overstimulated.

Surgical repair or replacement of the valve (see below) may be recommended if you have:

  • severe mitral regurgitation causing symptoms
  • no symptoms but an enlarged lower heart chamber
  • severe mitral regurgitation with atrial fibrillation or pulmonary hypertension

Mitral valve stenosis

Mitral valve stenosis occurs when the mitral valve doesn't open as wide as it should, restricting the flow of blood through the heart.

As a result, less blood can get to the body and the upper heart chamber swells as pressure builds up. Blood and fluid can also collect in the lungs, making it hard for you to breathe.

The most common cause of mitral valve stenosis in adults is rheumatic fever , which can occur five to 10 years before the heart valve problems began. Rheumatic fever causes the valve to become inflamed (swollen), and over time the flaps of the inflamed valve stick together and become scarred, rigid and thickened.

Rarercauses of mitral valve stenosis include calcium deposits forming around the valve, radiation treatment to the chest and some medications.

Mitral valve stenosis may not cause any symptoms, but common warning signs include shortness of breath and an abnormally fast heart rhythm ( atrial fibrillation ).

Ifyou don't have any symptoms, your heart function may just be monitored at regular intervals with echocardiography (an ultrasound scan of the heart).

Some people will be offered medications called nitrates or diuretics to reduce the build-up of fluid in the lungs, medication to treat atrial fibrillation and medication to prevent blood clots .

If you have symptoms, you're at risk of heart failure if you do not have an operation either to open up the valve (percutaneous balloon valvuloplasty) or have it replaced. See below for more information about these procedures.

Left untreated, moderate to severe mitral stenosis can lead to Heart failure .

Content supplied by the NHS Website

Medically Reviewed by a doctor on 21 Dec 2018