Mitral regurgitation - acute Health Article

Definition

Acute 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.

See also: Chronic mitral regurgitation

Alternative Names

Mitral insufficiency; Acute mitral regurgitation

Causes, incidence, and risk factors

Regurgitation means leaking from a valve that doesn't close all the way. Diseases that weaken or damage the valve or its supporting structures cause mitral regurgitation.

When the mitral valve doesn't close all the way, 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.

Symptoms

• Chest pain -- unrelated to coronary artery disease or a heart attack
• Cough
• Rapid breathing
• Shortness of breath that increases when lying flat (orthopnea)
• Sensation of feeling the heart beat (palpitations)

Note: Symptoms may start suddenly.

Signs and tests

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.

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)