Mitral valve prolapse

Overview

Mitral valve prolapse (MVP) is a common cardiac condition in which one or both leaflets of the mitral valve bulge (prolapse) backward into the left atrium during the heart's contraction (systole). This abnormal valve movement can lead to the improper closure of the valve, resulting in the backward leakage of blood known as mitral regurgitation. MVP is often a benign condition, but in some cases, it may be associated with significant regurgitation, arrhythmias, or rarely, infective endocarditis and sudden cardiac death.

The mitral valve, located between the left atrium and left ventricle, ensures one-way blood flow through the heart. In MVP, the valve’s structure is altered due to abnormal connective tissue or other underlying factors, causing it to "flop" into the atrium. MVP affects approximately 2–3% of the general population and is more common in women. Most cases are diagnosed incidentally during routine cardiac examinations.

Causes

Mitral valve prolapse can be caused by various structural and genetic factors. It may occur as an isolated finding or as part of a broader connective tissue disorder. The underlying causes can be categorized as follows:

Primary (Myxomatous Degeneration)

• Thickening and redundancy of the mitral valve leaflets

• Elongation of the chordae tendineae (tendinous cords supporting the valve)

• Commonly associated with connective tissue disorders

Secondary (Functional) MVP

• Changes in the left ventricle geometry (e.g., due to dilated cardiomyopathy)

• Ischemic heart disease affecting the papillary muscles

Genetic and Syndromic Associations

• Marfan syndrome

• Ehlers-Danlos syndrome

• Loeys-Dietz syndrome

• Familial MVP due to mutations in genes affecting connective tissue proteins (e.g., FBN1)

Other contributing factors include aging, rheumatic heart disease, and endocarditis, which may lead to acquired MVP.

Symptoms

Many individuals with mitral valve prolapse are asymptomatic and remain undiagnosed. However, in symptomatic patients, the presentation can vary widely and may include:

Cardiac Symptoms

• Palpitations or awareness of heartbeats

• Chest pain (non-anginal in nature)

• Fatigue and exercise intolerance

• Shortness of breath, especially with exertion

• Lightheadedness or dizziness

Symptoms of Mitral Regurgitation

• Dyspnea (difficulty breathing)

• Orthopnea (shortness of breath when lying flat)

• Paroxysmal nocturnal dyspnea (sudden night-time breathlessness)

• Peripheral edema (swelling in legs or ankles)

Autonomic Symptoms

• Anxiety or panic attacks

• Cold extremities

• Frequent urination

In rare cases, MVP may be associated with serious complications such as atrial fibrillation, stroke (due to emboli), or sudden cardiac death.

Diagnosis

Mitral valve prolapse is typically diagnosed during a physical examination or through cardiac imaging. The diagnostic process includes:

1. Physical Examination

• Mid-systolic click: Classic auscultatory finding heard best at the apex or lower left sternal border

• Late systolic murmur: Follows the click if mitral regurgitation is present

2. Echocardiography

• Transthoracic echocardiogram (TTE): First-line imaging to visualize leaflet prolapse and assess mitral regurgitation

• Transesophageal echocardiogram (TEE): Provides more detailed images, especially if surgery is considered

3. Electrocardiogram (ECG)

• Usually normal, but may show nonspecific ST-T wave changes or arrhythmias

4. Holter Monitoring

• Used to detect intermittent arrhythmias or palpitations

5. Chest X-ray and MRI

• May be used in selected cases to evaluate cardiac size and function

Routine screening is not necessary in asymptomatic individuals without complications or a family history of MVP-related issues.

Treatment

Treatment for mitral valve prolapse depends on symptom severity and the presence of mitral regurgitation or complications. Most patients require only monitoring and reassurance.

1. Lifestyle and Monitoring

• Regular follow-up with echocardiography to monitor valve function

• Healthy lifestyle with regular exercise and balanced diet

• Avoidance of stimulants (e.g., caffeine, nicotine) in symptomatic individuals

2. Medications

• Beta-blockers: For palpitations, chest discomfort, and autonomic symptoms

• Antiarrhythmic agents: In cases of documented arrhythmias

• Diuretics: To relieve symptoms of heart failure in patients with severe mitral regurgitation

• Anticoagulants: If atrial fibrillation or embolic events occur

3. Surgical Intervention

• Mitral valve repair: Preferred option for severe regurgitation with preserved heart function

• Mitral valve replacement: Considered when repair is not feasible

• Minimally invasive and robotic-assisted procedures may be options in select centers

Early surgical referral is recommended if there is evidence of left ventricular dysfunction or worsening symptoms despite optimal medical therapy.

Prognosis

The prognosis for most individuals with mitral valve prolapse is excellent, especially in cases without significant regurgitation or complications. Many patients lead normal, active lives without requiring intervention.

However, prognosis may vary based on:

• Severity of mitral regurgitation

• Presence of arrhythmias or heart failure

• Underlying connective tissue disorders

• Response to treatment and follow-up care

With regular monitoring and appropriate management, the risk of progression to heart failure or sudden death remains low. Surgical outcomes for mitral valve repair are highly successful, particularly when performed early in disease progression.