Mitral Insufficiency

What is Mitral Insufficiency?

Mitral insufficiency - also known as mitral regurgitation - occurs when a damaged mitral valve allows blood from the left ventricle to flow back into the left atrium during systole. As a result, the atrium enlarges to accommodate the backflow. The left ventricle also dilates to accommodate the increased volume of blood from the atrium and to compensate for diminishing cardiac output.

Mitral insufficiency tends to be progressive because left ventricular dilation increases the insufficiency, which further enlarges the left atrium and ventricle, which further increases the insufficiency.

Causes of Mitral Insufficiency

Damage to the mitral valve can result from rheumatic fever, hypertrophic cardiomyopathy, mitral valve prolapse, myocardial infarction, severe left-sided heart failure, or ruptured chordae tendineae.

In older patients, mitral insufficiency may occur because the mitral annulus has become calcified. The cause is unknown, but it may be linked to a degenerative process. Mitral insufficiency is sometimes associated with congenital anomalies such as transposition of the great arteries.

Signs & Symptoms of Mitral Insufficiency

• Fatigue, especially during times of increased activity
• Shortness of breath
• Cough
• Heart murmur
• Excessive urination

Note: Often no symptoms are present. When symptoms occur, they often develop gradually.

Diagnostic Tests

Cardiac catheterization is used to detect mitral insufficiency, with increased left ventricular end-diastolic volume and pressure, increased left atrial and pulmonary artery wedge pressures, and decreased cardiac output.

Chest X-rays demonstrate left atrial and ventricular enlargement, pulmonary vein congestion, and calcification of the mitral leaflets in long-standing mitral insufficiency and stenosis.

Echocardiography reveals abnormal motion of the valve leaflets, left atrial enlargement, and a hyperdynamic left ventricle.

Electrocardiography may show left atrial and ventricular hypertrophy, sinus tachycardia, and atrial fibrillation.

Treatment

The nature and severity of associated symptoms determine treatment in valvular heart disease. The patient may need to restrict activities to avoid extreme fatigue and dyspnea.

Heart failure requires digoxin. diuretics, a sodium-restricted diet and, in acute cases, oxygen. Other appropriate measures include anticoagulant therapy to prevent thrombus formation around diseased or replaced valves and prophylactic antibiotics before and after surgery or dental care.

If the patient has severe signs and symptoms that can't be managed medically, he may need open-heart surgery with cardiopulmonary bypass for valve replacement.

Valvuloplasty may be used in elderly patients who have end-stage disease and can't tolerate general anesthesia.

Prevention Tips

One possible way to prevent mitral valve regurgitation is to prevent rheumatic fever. You can do this by making sure you see your doctor when you have a sore throat. Untreated strep throat can develop into rheumatic fever. Fortunately, strep throat is easily treated with antibiotics.

Any dental work, including cleaning, and any invasive procedure can introduce bacteria into the bloodstream. This bacteria can infect a damaged mitral valve, causing endocarditis. Preventive treatment with antibiotics given just before dental or other invasive procedures may decrease the risk of endocarditis.