Mitral Regurgitation

About Your Diagnosis
The mitral valve is the valve in the heart between the left atrium and left ventricle. It opens when the atrium pumps blood into the ventricle. It closes then the ventricle pumps blood out of the ventricles to the body. This prevents the blood from going back into the atrium. If blood leaks back into the atrium from the ventricle this is called regurgitation. Sometimes it is called mitral insufficiency or mitral incompetence. If blood regurgitates back into the atrium, it is not pumped out of the heart efficiently, and the atrium cannot fill with the next cycle. Blood may become backed up in the right heart system (to the lungs) causing fluid to accumulate in the lungs. This means the left ventricle has to do more work to move the blood. After a while, the extra work may cause the heart to fail in its function.

Living With Your Diagnosis
Mitral regurgitation is caused by damage that happens to the mitral valve. The damage may be from a congenital abnormality (one that is present at birth). It may come from a heart attack (myocardial infarction, in which parts of the heart muscle or valve die because they do not have enough blood supply). An infection such as rheumatic fever (from streptococcal infections such as strep throat) also can cause damage to the valve. Connective tissue disorders such as lupus and inherited conditions such as Marfan syndrome may affect the mitral valve. Mitral valve prolapse also can lead to mitral regurgitation. Blood moves abnormally through the valve in mitral regurgitation, producing an abnormal sound called a murmur. The murmur is heard when the heart is examined with a stethoscope. The timing of the murmur in the cardiac cycle and the location of the murmur help determine which valve is affected. Often patients live for years without ever knowing of this condition. Most patients have no symptoms if the defect is small. Symptoms may develop after a few years and usually include fatigue and difficulty breathing. Chest radiographs (x-rays) often show the left atrium enlarged (from overfilling) and fluid leaking into the lungs. Arrhythmias (such as atrial fibrillation) occur if the changes in the atrium affect the electrical system of the heart. This may cause palpitations or a rapid heartbeat.

Treatment
Management of mitral regurgitation varies with severity. If the condition is mild, attempts are made to prevent possible complications. Abnormally functioning valves may be a target for an infection called endocarditis. Antibiotics are routinely given to patients with known mitral regurgitation for dental or surgical procedures and for bacterial infections to prevent spread of infection to the valve. Digitalis (digoxin) may be given for atrial fibrillation
and heart failure. Some patients with atrial fibrillation are given anticoagulant medications to prevent a blood clot from forming in the atrium. If there is evidence of heart failure, diuretics may be used to reduce the fluid volume in the blood. Vasodilators such as nitrates, hydralazine, captopril, or enalapril may be used if heart failure becomes more prominent. These drugs decrease the workload on the heart. If heart failure becomes unmanageable with medication or the ability of the heart to keep working is threatened, heart valve replacement may be needed. Side effects of the medications vary depending on the drug and choice of therapy. Allergies to antibiotics or the other drugs may exist. Digoxin levels in the blood must be checked periodically to limit side effects. Diuretics cause frequent urination and can cause dehydration and electrolyte (salt) abnormalities in the blood. Extra potassium pills may be needed if diuretics are used, and these can cause nausea, vomiting, or diarrhea. Nitrate medications may cause headaches or dizziness, and the other vasodilators can cause lightheadedness, fatigue, and intestinal problems.

The DOs
•Take your medications as directed.
•Restrict fluid and salt in your diet if you have symptoms of heart failure.
•Take antibiotics as prescribed before and after dental or surgical treatments, including tooth cleanings.
•Exercise as tolerated.

The DON’Ts
•Do not ignore worsening symptoms.

When to Call Your Doctor
•If you have side effects from your medications.
•If you have new or worsening symptoms, specifically chest pain, shortness of breath, difficulty breathing at rest, lightheadedness, palpitations (rapid heartbeat), or new swelling in your feet or legs.