Mitral regurgitation (patient information)

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 * Katherine Ogando

Overview
Mitral regurgitation is a disorder in which the heart's mitral valve suddenly does not close properly, causing blood to flow backward (leak) into the upper heart chamber when the left lower heart chamber contracts. Acute mitral regurgitation can develop into chronic mitral regurgitation, a long-term disorder.

What are the symptoms of Mitral regurgitation?
Symptoms for acute mitral regurgitation include chest pain unrelated to coronary artery disease or heart attack, cough, rapid breathing, shortness of breath that increases when lying flat (orthopnea), and sensation of feeling the heart beat (palpitations). These symptoms may start suddenly.

For chronic mitral regurgitation there are often no symptoms. When symptoms do occur, they often develop gradually and may include cough, fatigue, exhaustion, and light-headedness, palpitations (related to atrial fibrillation), shortness of breath during activity and when lying down, and excessive urination at night.

What causes Mitral regurgitation?
Regurgitation means leaking from a valve that doesn't close all the way. It is caused by diseases that weaken or damage the valve or its supporting structures. Mitral regurgitation becomes chronic when the condition persists rather than occurring for only a short time period. Chronic mitral regurgitation should be distinguished from acute mitral regurgitation.

Acute Mitral Regurgitation
In acute mitral regurgitation, the mitral valve doesn't close all the way and blood flows backward into the left upper heart chamber (atrium). This leads to a decrease in blood flow to the rest of the body. As a result, the heart may try to pump harder.

Acute mitral regurgitation may be caused by dysfunction or injury to the valve following a heart attack or infection of the heart valve (infective endocarditis). These conditions may rupture the valve or surrounding structures, leaving an opening for blood to move backwards.

Chronic Mitral Regurgitation
Mitral valve prolapse is a relatively common cause of chronic mitral regurgitation.

About one-third of all cases of chronic mitral regurgitation are caused by rheumatic heart disease, a complication of untreated strep throat that is becoming less common.

Congenital (present from birth) mitral regurgitation is rare if it is not part of a more complex heart defect or syndrome.

Chronic mitral regurgitation can also be caused by:


 * Atherosclerosis
 * Endocarditis
 * Heart tumors
 * High blood pressure
 * Marfan syndrome
 * Swelling of the left lower heart chamber
 * Untreated syphilis (rare)

Risk factors include an individual or family history of any of the disorders mentioned above and use of fenfluramine or dexfenfluramine (appetite suppressants banned by the FDA) for 4 or more months.

Who is at highest risk?
Persons who already have cardiac disease, sustained trauma to the chest area, have congenital heart abnormalities, or have had endocarditis or rheumatic fever are at risk for mitral regurgitation.

Diagnosis
The doctor may detect a thrill (vibration) over the heart when feeling (palpating) the chest area. An extra heart sound (S4 gallop) and a distinctive heart murmur may be heard when listening to the chest with a stethoscope. However, some patients may not have this murmur. If fluid backs up into the lungs, there may be crackles heard in the lungs.

Blood pressure is usually normal. In cases of chronic mitral regurgitation, the physical exam may also reveal ankle swelling, enlarged liver, distended neck veins, and other signs consistent with right-sided heart failure.

The following tests may be performed:


 * Cardiac catheterization
 * Chest MRI scan
 * Chest x-ray - may also show fluid in the lungs or prominent lung veins
 * Color flow Doppler exam
 * CT scan of the chest
 * Echocardiogram
 * ECG - usually shows a normal sinus rhythm but may show abnormal heart rhythms
 * Radionuclide scans
 * Right heart catheterization - may show high left atrial pressure.
 * Transesophageal echocardiogram (TEE)

When to seek urgent medical care?
Call your health care provider if you have symptoms of mitral valve regurgitation, or if symptoms worsen or do not improve with treatment.

Call your health care provider if you are being treated for this condition and develop signs of infection, which include:


 * Chills
 * Fever
 * General ill feeling
 * Headache
 * Muscle aches

Treatment options
If you have severe symptoms, you may need to be admitted to a hospital for diagnosis and treatment. Emergency surgery may be necessary for severe leakages, usually resulting from infection, heart attack, or rupture of a valve structure.

Medications prescribed to you may include:


 * Antibiotics to fight any bacterial infections
 * Antiarrhythmics to control heart rhythms
 * Blood thinners to prevent clot formation if atrial fibrillation is present (mainly used for patients with chronic mitral regurgitation)
 * Digitalis to strengthen the heartbeat
 * Diuretics (water pills) to remove excess fluid in the lungs
 * Vasodilators to dilate blood vessels and reduce the workload of the heart

If blood pressure cannot be controlled, an intra-aortic balloon pump (IABP) may be used to help move blood forward into the aorta, the main artery from the heart.

In chronic cases, you may be treated with anti-hypertensive drugs and vasodilators to reduce the strain on the heart and to help improve the condition. A low-sodium diet may also be helpful. Most individuals have no symptoms; but if a person develops symptoms, activity may be restricted.

Surgical repair or replacement of the valve is recommended if heart function is poor, if symptoms are severe, or if the condition deteriorates. Once the diagnosis of mitral regurgitation is made, periodic follow-up by a specialist is needed to determine the appropriateness of surgery.

Where to find medical care for Mitral regurgitation?
Directions to Hospitals Treating Mitral regurgitation

Prevention
Prompt treatment of disorders that can cause mitral regurgitation reduces your risk.

Any invasive procedure, including dental work and cleaning, can introduce bacteria into your bloodstream. The bacteria can infect a damaged mitral valve, causing endocarditis. Always tell your health care provider and dentist if you have a history of heart valve disease or congenital heart disease before treatment. Taking antibiotics before dental or other invasive procedures may decrease your risk of endocarditis.

What to expect (Outlook/Prognosis)?
How well a patient does depends on the cause and severity of the valve leakage. Milder forms may become a chronic condition.

Acute mitral regurgitation can rarely be controlled with medications. Surgery is usually needed to repair or replace the mitral valve.

Abnormal heart rhythms associated with acute mitral regurgitation can sometimes be deadly.

Possible complications

 * Arrhythmias (abnormal heart rhythms), including atrial fibrillation and lethal arrhythmias.
 * Clots to other areas.
 * Endocarditis (infection of the heart valve).
 * Heart failure.
 * Pulmonary emboli (blood clots in the lungs).
 * Stroke.