Mitral Regurgitation: Symptoms and Treatment

The heart is divided into four major chambers, the left atrium, left ventricle, right atrium and the right ventricle. The valve present between the left atrium and the left ventricle is called the mitral valve. The valve present between the right atrium and the right ventricle is called the tricuspid valve. When the mitral valve doesn’t close properly, it may allow the blood to backflow into your heart, because of which enough blood doesn’t reach your body; this condition is called Mitral Regurgitation (MR)

Causes of Mitral Regurgitation

The mitral regurgitation can be due to a problem in the valves, or due to a problem in the annulus on which the leaflets of the valve are present.

• Rheumatic heart disease: a long term consequence of multiple episodes of rheumatic fever which in itself is a complication of the common strep throat. MR due to Rheumatic heart disease may be accompanied by mitral stenosis on some occasions
• Mitral valve prolapse: the valve leaflets bulge into the atrium and prevent the valves from closing properly leading to backflow.
• Genetic disorders: like Marfan syndrome and Ehler-Danlos syndrome predispose individuals to MR
• Infective endocarditis: an infection of the heart in which the infection may sometimes lead to perforations in the heart valve, hence leading to regurgitation.
• Dilated cardiomyopathy: dilation of the heart may lead to an increase in the size of the ring on which the valves leaflets are attached. The dilation may prevent proper approximation of the leaflets leading to regurgitation. Dilated cardiomyopathy can be caused due to multiple reasons.
• Heart attack: it may cause damage to the cords and the associated muscles which are holding the valve in its place.

Other causes are drug induced MR, radiation exposure, sudden tear of the cord supporting the mitral valve, Systemic lupus erythematosus.

Symptoms of Mitral Regurgitation

Mitral regurgitation leads to an inadequate blood flow to the body which leads to its symptoms. They are:

• Difficulty in breathing after doing exercise
• Fatigue
• Swelling in feet or ankle
• Sensation of rapid, erratic heartbeat

Diagnosis of Mitral Regurgitation

Your doctor would like to listen to complains that you have and then perform an examination of your heart and lungs to confirm the suspicions of a mitral regurgitation. A battery of tests may be ordered by your cardiologist to confirm the diagnosis.

• Electrocardiogram: small leads will be placed on your chest to assess the electrical activity of the heart. This indirectly tells your doctor if there are structural abnormalities in your heart or not.
• Echocardiogram: a small rod like probe will be placed on your heart, it produces sound waves and is used to visualise the chambers of the heart and see the valves in action. This procedure allows your doctor to have a closer look at the valves and hence identify the severity of the regurgitation.
• Trans esophageal echocardiography (TEE): sometimes when the results of a echocardiography aren’t conclusive your doctor will order for a TEE. For this procedure the sound wave producing probe is introduced into your food pipe via your mouth for a better visualisation of the heart.
• Magnetic Resonance Imaging (MRI): used to assess the functional status of your left ventricle, also used when echocardiography results aren’t satisfactory. The results will affect the future course of action.
• Chest X ray: a radiography of your chest can tell your doctor whether your left atrium or left ventricles is enlarged.
• Cardiac catheterization: a procedure not used very frequently for valve problems; a small tube is inserted into the artery of your groin or your arm to reach the heart. There it is used to visualise the chambers of your heart and assess the severity of the regurgitation. It can also be used to measure the pressure in the different chambers of the heart.

Complications of Mitral Regurgitation

When left untreated mitral regurgitation can lead to:

• Atrial fibrillation: stretching of the walls of the left atrium predisposes individuals with MR to atrial fibrillation
• Heart failure: it occurs when the heart is not able to pump enough blood to meet the demands of the body. The continuous regurgitation of blood through the mitral valve reduces the efficiency of the heart and increases its workload which eventually leads to heart failure.
• Pulmonary hypertension: constant back flow of blood causes an increase in the pressure of the left atrium which is reflected in the blood pressure in the vessels of the lungs. This condition is called pulmonary hypertension, which may eventually lead to a failure in the functioning of the right side of the heart.

Treatment of Mitral Regurgitation

The treatment aims to reduce your symptoms and chances of further complications. Surgical treatment may help in correcting the defect in the heart.

• Medical treatment: Blood thinners if you have had atrial fibrillation, to prevent clot formation ACE inhibitors and beta blockers will be prescribed if you have hypertension because hypertension causes a worsening of the symptoms.
• Mitral Clip (Non-operative percutaneous treatment): a thin tube in inserted into a vein in your groin and pushed forward until it reaches the right side of the heart. Here it pierces the wall separating the left and the right atrium and enters the left atrium. Your doctor then introduces a clip which pinches the leaflet together creating a figure of eight opening hence reducing the chances if mitral regurgitation. It is generally done for patients who cannot undergo an open heart surgery.
• Mitral valve repair: your surgeon will perform and open heart surgery to repair the damaged part of the leaflets, replace the cords the support the valve and sometimes also mend the annulus on which the leaflets are present.
• Mitral valve replacement surgery: sometimes when the valve is damaged beyond repair your surgeon will suggest that you opt for a mitral valve replacement. In this procedure the damaged valve is replaced with a valve made of human, cow or pig. If you undergo this procedure you will have to take low doses of blood thinners all your life. The replaced valve undergoes biological degradation and hence may require replacement over the time of few years.

Resources:

• American Heart Association
• http://www.acc.org/guidelines