Mitral valve stenosis is a form of valvular heart disease. It occurs when there is a narrowing of the mitral valve, which restricts the flow of blood from the left atrium to the left ventricle.

The mitral valve is in the heart, between the left atrium and left ventricle. The primary function of the mitral valve is to stop the blood in the heart flowing the wrong way. Stenosis is a term that refers to the narrowing of a body passage or opening.

Mitral valve stenosis (MVS) is a form of valvular heart disease that can occur when the mitral valve opening becomes narrow, stiff, and unable to fully open to allow the blood to flow through.

In this article, we will discuss the causes and symptoms of MVS, alongside some treatment options that are available.

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The mitral valve is a heart valve that sits between the left atrium and the left ventricle. When the valve is functioning correctly, the primary function is to allow the blood to flow from the left atrium to the left ventricle and to stop it from going in the wrong direction.

MVS is a type of valvular heart disease that causes the narrowing and hardening of the mitral valve. This restricts the flow of blood through the heart and increases the pressure in the left atrium, causing the left atrium to enlarge.

This can lead to pulmonary hypertension, which is high blood pressure in the blood vessels that supply the lungs. A person may also have a greater chance of developing atrial fibrillation, which is an irregular heartbeat, or heart failure.

RHD can occur when a person has had rheumatic fever, which results from an untreated strep infection and can damage the valves in the heart. However, symptoms may not present until 10–15 years after an episode of rheumatic fever.

Other causes of MVS include:

  • Calcific mitral stenosis: This is a buildup of calcium on the heart valves, which is more likely to happen when a person is older.
  • Congenital heart defects (CHDs): This refers to heart problems that are present at birth and affect the structure of the heart and how it works.
  • Lupus: This is a chronic autoimmune disease that can affect almost any organ in the body.

It is possible that MVS does not present with any symptoms. A doctor may advise a person with MVS that is not presenting any symptoms to attend regular appointments to monitor their condition.

If a person has symptomatic MVS, some of the symptoms may include:

  • fatigue
  • weakness
  • dizziness or fainting
  • breathlessness
  • heart palpitations
  • chest pain
  • fever
  • blood in the phlegm
  • blood clots

To diagnose MVS, a doctor will listen to the heart and may be able to detect an unusual sound. Depending on the location of the sound, a doctor may be able to determine if they think the person has MVS.

To confirm this diagnosis, a doctor may need to look more closely at the heart and perform several tests. Some of these may include:

There are several medications available that may help to relieve some of the symptoms of MVS. These include:

A person with MVS may be able to undergo a surgical procedure to repair or replace the mitral valve. This will depend on the cause of MVS, how damaged the valve is, whether surgery may put the person at risk, how severe the symptoms are, and how the heart is functioning.

Some of the procedures may include:

  • Balloon valvuloplasty: A minimally invasive procedure that may be able to repair the valve by placing a small balloon inside it to stretch it and create space.
  • Valve replacement: A doctor may recommend surgery to replace the mitral valve with a mechanical valve made with durable materials or a tissue valve from a donor.
  • Mitral valve commissurotomy: If a person has rheumatic mitral stenosis, they may require a commissurotomy, where a surgeon separates the opening of the valve that has fused together.

A doctor may advise a person with MVS to make some lifestyle changes, including gentle exercise and eating a healthy, low-sodium diet.

If a person has advanced MVS, a doctor may ask them to reduce physical activity in order to avoid putting strain on the heart.

Once symptoms of MVS are present, the condition typically accelerates rapidly. Approximately 8 in 10 people with MVS do not live longer than 10 years from when the symptoms became apparent.

If a person with symptomatic MVS does not seek any form of treatment, there can be several serious health complications, including:

  • heart failure
  • delays in weight gain or growth
  • stroke
  • pulmonary hypertension — high blood pressure in the blood vessels that supply the lungs
  • endocarditis — an infection of the lining of the heart
  • an irregular heartbeat

Mitral valve stenosis can occur when the mitral valve narrows and stiffens, causing a restriction in blood flow.

The most common cause of MVS is rheumatic heart disease, resulting from rheumatic fever. Symptoms may not present until 10–15 years after an episode of rheumatic fever. Symptoms of MVS can include fatigue, weakness, heart palpitations, and chest pain.

There are several medications available to help relieve the symptoms of MVS and surgical options to repair or replace the mitral valve. If a person with MVS does not seek the relevant treatment, it can lead to serious health complications, including heart failure.