Mitral Valve Disease: Regurgitation, Stenosis and Prolapse

What is the mitral valve?

The mitral valve has two leaflets and lies between the left atrium and left ventricle. It opens to let blood enter the ventricle and closes during contraction to prevent backward flow. Its main abnormalities are regurgitation, stenosis and prolapse. These conditions can occur alone or together.

Mitral regurgitation

Mitral regurgitation means blood leaks backwards into the left atrium when the ventricle contracts. Significant chronic leakage can enlarge the left atrium and ventricle and contribute to atrial fibrillation and heart failure.

Causes

Primary regurgitation involves the valve leaflets or supporting structures, for example prolapse, degenerative changes, ruptured chordae, rheumatic disease or endocarditis. Secondary regurgitation results from changes in the size or function of the ventricle or atrium, as may occur with coronary disease, cardiomyopathy or atrial fibrillation.

Symptoms and diagnosis

Mild disease often causes no symptoms. More significant regurgitation may cause breathlessness, fatigue, palpitations, reduced exercise tolerance or swelling. Acute severe leakage can cause pulmonary oedema and circulatory instability.

Echocardiography evaluates the mechanism and severity of leakage, chamber dimensions, ejection fraction and pulmonary pressures. Severity is assessed from several measurements rather than one colour Doppler image. Transoesophageal echocardiography may be needed for detailed anatomy and procedure planning. MRI or other tests can clarify selected cases.

Treatment

Follow-up is appropriate for mild or moderate disease. In secondary regurgitation, appropriate heart failure therapy is central. Medicines do not correct the structural lesion of primary regurgitation, although associated conditions should be treated.

When intervention is required, options include mitral repair, valve replacement and transcatheter edge-to-edge repair in suitable patients. Durable repair is preferred in many patients with degenerative primary disease. Decisions consider symptoms, ventricular size and function, pulmonary pressure, rhythm, anatomy and procedural risk.

Mitral stenosis

Mitral stenosis restricts blood flow from the left atrium to the left ventricle. It can raise left atrial and pulmonary pressures and lead to breathlessness, fatigue, atrial fibrillation and heart failure.

Rheumatic heart disease is an important cause. Other causes include severe annular calcification and congenital abnormalities. Symptoms may include exertional breathlessness, palpitations, difficulty lying flat, cough and occasionally coughing blood.

Echocardiography assesses valve area, mean pressure gradient, anatomy and pulmonary pressure. The gradient depends on heart rate and blood flow and should not be interpreted alone. Transoesophageal imaging may be used to exclude an atrial clot before intervention.

Medication can relieve congestion, control heart rate and address clot risk, but does not remove the mechanical narrowing. Balloon mitral valvotomy may be effective for suitable rheumatic anatomy without important regurgitation or an atrial clot. Other patients may require surgery.

Atrial fibrillation with moderate-to-severe rheumatic mitral stenosis carries an increased stroke risk. Vitamin K antagonist therapy is generally used; direct oral anticoagulants are not a substitute in this setting.

Mitral valve prolapse

Prolapse occurs when one or both leaflets move excessively into the left atrium during contraction. Many people have no significant regurgitation and do well. Some develop progressive leakage or arrhythmias.

Palpitations, chest discomfort and dizziness are not always directly caused by prolapse. Unexplained fainting, complex ventricular ectopy, myocardial fibrosis or particular valve features may justify more detailed rhythm assessment. Prolapse does not mean that every patient has a high risk of sudden death.

Treatment depends on symptoms and the degree of regurgitation. It may involve observation, selected medication or valve intervention when significant disease develops.

Why are regular checks important?

Important valve disease may affect the heart before symptoms become obvious. Attend recommended clinical and echocardiographic follow-up. New exertional breathlessness, palpitations or reduced exercise capacity should prompt review.

Sudden severe breathlessness, fainting, ongoing chest pain or stroke symptoms requires emergency care. Call 112.

Assoc. Prof. Sezen Bağlan Uzunget, MD — Cardiologist

This information is educational. Diagnosis and intervention decisions require individual assessment.

Türkçe: Mitral Kapak Hastalıkları