Mitral valve stenosis

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at June 20, 2016
StartDiseasesMitral valve stenosis

A healthy mitral valve opens and closes to allow blood into the primary chamber of an individual's heart. When the mitral valve is narrowed, the left ventricle must contract much harder to pump blood throughout the body. This condition is known as mitral valve stenosis (MVS), and it can result in a variety of serious health conditions if left untreated.

Contents

Definition & Facts

While mitral valve stenosis is a relatively rare condition, over 90 percent of patients who have rheumatic heart disease (valvular heart disease that results from rheumatic fever) eventually develop MVS. This particular disease is almost always the result of a patient having had a rheumatic fever when they were younger. Once the patient's heart has been weakened by the fever and subsequent disease, there is a very high likelihood that one or more valves in their heart will no longer work properly.

While MVS can take place in either sex, women develop this condition at much higher rates. Patients who do not have access to antibiotics also have a higher risk of developing MVS. Ongoing studies recently revealed that incidences of rheumatic fever have declined from 10 percent to .01 percent over the last 80 years. 

Symptoms & Complaints

One of the reasons why mitral valve stenosis is so difficult to diagnose is because patients can have this condition for decades without showing any symptoms. Many patients who develop MVS in their teens will not begin to notice any serious symptoms until they are well into their 50s.

The most common symptom is general lethargy. Patients with MVS often complain of fatigue after any physical activity. They might also feel chest tightness or pain in their chest throughout the day or when their heart rate increases.

Because sometimes the fluid in one's heart can become lodged in the lungs, MVS patients almost always exhibit flu-like symptoms. This includes hoarseness, coughing fits, heart murmurs, and congestion. Some patients also experience swelling of their hands and feet due to high blood pressure

Causes

Almost any condition that weakens the heart can result in MVS. This includes bacterial infections like strep throat. Strep throat only accounts for a small percentage of sore throats, but it is much more severe than the average illness. When it is not treated immediately, it can result in a rheumatic fever. Rheumatic fever is the single most common cause of MVS because of the fact that it causes one's heart valves to thicken and fuse.

In some rare cases, mitral valve stenosis can be caused by congenital heart defects. This includes unusual calcium deposits or a narrowed mitral valve. Patients who have been diagnosed with autoimmune diseases such as lupus should be tested for MVS as well. Older individuals with kidney disease also tend to develop MVS at much higher rates. This particular condition can harden one's vessels as well as valves within their heart.

Diagnosis & Tests

Patients should immediately contact their doctor if they have noticed any of the symptoms listed above. Typically, doctors will begin the physical examination by listening to the patient's heart and lungs with a stethoscope. If they notice any irregularities with the patient's heartbeat or their breathing, then they will schedule an electrocardiogram (ECG). This is a pain-free test that utilizes electrodes to measure the electrical impulses coming from the patient's heart. During this test, the patient might be asked to walk on a treadmill or ride a stationary bike to get a better reading, which is called a cardiac stress test.

Another common MVS test is a chest X-ray. The images that are collected from an X-ray will tell the doctor if any of the patient's heart valves are swollen or damaged. When these tests are inconclusive, the doctor might suggest switching over to a cardiac catheterization to get a better idea of what is taking place in the patient's heart. Cardiac catheterizations utilize medical-grade dyes placed in the heart to get a better X-ray reading. 

Treatment & Therapy

Patients who have mild MVS typically do not need any treatments whatsoever. The doctor might suggest regular testing to ensure that the condition does not become worse. While medication cannot reverse mitral valve stenosis, it can lessen the side effects. Diuretics are generally the first type of medication given to patients with MVS. These reduce the accumulation of fluid in one's heart and lungs. Many patients are also given aspirin to thin their blood and reduce the risk of blood clots. For those who have a high risk of developing a rheumatic fever, long-term antibiotics might be needed.

Advanced cases of MVS almost always require surgery. During open-heart surgery, the doctor will attempt to remove the calcium from the valve or replace the valve entirely. The other option is a procedure known as a balloon valvuloplasty. During a valvuloplasty, a balloon will be inserted into an artery and then directed up to the patient's heart. Once in place, the balloon is inflated to increase the size of the chamber. This procedure can be carried out periodically to lessen the side effects, but it is not a permanent solution. 

Prevention & Prophylaxis

The single most effective way to prevent mitral valve stenosis is to prevent rheumatic fever. In order to do this, parents should immediately seek out medical attention for their child if they notice any flu-like symptoms or the child complains of a sore throat.

While strep throat can be a dangerous illness, it is easily treated with a battery of antibiotics. Failing to treat strep throat can result in a wide range of additional complications including rheumatic fever and rheumatic valvular disease.

Some of the lifestyle factors that could increase one's risk of developing MVS include heavy drinking, the use of tobacco products, and the consumption of foods that are high in sodium. While these factors do not directly cause MVS, they can weaken the heart's valves. High cholesterol and diabetes have also been linked to mitral valve stenosis. Patients who eat well, exercise regularly, and stay at a healthy weight will reduce their risk of MVS.