Mitral Valve Prolapse

Key points

• Mitral valve prolapse is a condition in which one or both of the mitral valve leaflets are distended during systole, bulging into into the left atrium
• Abnormality may be detected on auscultation and can be confirmed with echocardiogram
• Treatment, when necessary, is aimed at minimizing palpitations, chest pain, fatigue, or autonomic dysfunction; daily aspirin therapy, warfarin, or β-blockers may be prescribed in rare cases
• Urgent action is seldom called for, but complications of this condition, including infective endocarditis and ruptured chordae tendineae, may require immediate referral and aggressive treatment

Background

Description

• Abnormality of the mitral valve in which one or both of the valve's leaflets bulge into the left atrium during systole, with or without valvular insufficiency. In most instances, the condition is benign and not progressive
• Hallmark auscultatory features are a midsystolic click and/or a late-systolic or pansystolic murmur
• A subset of patients with mitral valve prolapse have mitral valve prolapse syndrome, in which the mitral valve abnormality occurs in conjunction with atypical chest pain, palpitations, and/or autonomic dysfunction
• Endocarditis prophylaxis prior to dental, oral, respiratory tract, or esophageal procedures is no longer indicated for patients with mitral valve prolapse even if they also have mitral regurgitation or thickened leaflets

Epidemiology

Prevalence

• The reported prevalence (20-60 per 1,000) of this abnormality is dependent on the diagnostic criteria used to define the condition

Demographics

Age:

• Can occur at any age
• Patients aged older than 45 years face a greater likelihood of complications

Gender:

• Prevalence is greater in the female population and most commonly diagnosed in women aged 20 to 30 years
• Men aged older than 50 are at the highest risk of complications

Genetics:

• May be inherited as an autosomal-dominant trait, but with variable phenotypic expression

Causes and risk factors

Common causes:

• Primary disorder involving myxomatous degeneration of the mitral valve

Rare causes:

• Hereditary connective tissue disorders including Marfan syndrome, Ehlers-Danlos syndrome, and osteogenesis imperfecta
• Postinflammatory changes to the heart including those following rheumatic fever
• Congenital malformations such as Ebstein's anomaly of the tricuspid valve as well as large atrial septal defect
• Collagen vascular disease
• Coronary artery disease
• Cardiomyopathies including hypertrophic cardiomyopathy

Associated disorders

• Tricuspid valve prolapse (rare)
• Autonomic dysfunction including orthostatic hypotension
• Skeletal abnormalities including straight-back syndrome, scoliosis, and pectus excavatum
• Marfan syndrome

Screening

Not applicable.

Primary prevention

Not applicable.