Prolapse, mitral valve (MVP)

• Barlow’s syndrome
• Floppy mitral valve
• Mitral-click murmur syndrome
• Systolic-click murmur syndrome

• 424.0 Mitral valve disorders

• I34.1 Nonrheumatic mitral (valve) prolapse

• 6D: Impaired aerobic capacity/endurance associated with cardiovascular pump dysfunction or failure

Description

• Abnormally thickened mitral valve that becomes displaced into left atrium during systolic contraction
• Classic and non-classic
  • Non-classic carries low risk of complications
  • Complications of classic MVP include mitral valve regurgitation, endocarditis, congestive heart failure, cardiac arrest

Essentials of Diagnosis

• Stethoscope for auscultation systolic click in the mitral position, possible late systolic murmur
• EKG/ECG2
• Echocardiography
• Exercise stress test

General Considerations

• Education on disease management reduces hospitalization
• Patients with significant prolapse may show signs and symptoms of congestive heart failure
• Strenuous activity should be limited for symptomatic mitral prolapse
• Can lead to sudden cardiac death, arrhythmias, embolic events, and coronary disease
• Patients can develop bacterial endocarditis
• Mild to moderate prolapse generally does not cause symptoms

Demographics

• Prevalent in 2% of thin female adoloscents5
• Equal incidence of classic and non-classic
• Equal incidence between genders and age groups
• More common in patients with underlying genetic disease

Signs and Symptoms

• Murmur accentuated with standing, hand-grip maneuver, Valsalva maneuver, and diminished with squatting
• Cardiovascular collapse or shock
• Angina pectoris3
• Syncope3
• Congestive heart failure3
• Dyspnea on exertion
• Shortness of breath3
• Anginal chest pain that increases with exercise
• Orthopnea3
• Fatigue, weakness3
• Fainting, dizziness with activity
• Palpitations
• Palpable heaves/thrills over precordium
• Arrhythmias, particularly atrial fibrillation
• Endocarditis

Functional Implications

• Symptoms depend on degree of valvular dysfunction
• Severe mitral prolapse causes progressive shortness of breath and signs of congestive heart failure
• Patients may be unaware of reduced cardiovascular capacity
• MVP can cause syncope, chest pain, heart failure if severe

Possible Contributing Causes

• Excessive connective tissue in valve leaflets
• Ehler’s-Danlos syndrome
• Marfan syndrome
• Polycystic kidney disease
• Grave’s disease
• Pectus excavatum

Differential Diagnosis

• Acute coronary syndrome
• Aortic regurgitation
• Aortic stenosis
• Mitral valve regurgitation
• Mitral stenosis
• Myocardial infarction complication
• Shock, hypovolemia
• Cardiac pump dysfunction
  • Muscle dysfunction produces slight-to-moderate reduction in cardiac output (CO)
  • Mild-to-moderate activity limitation
  • Functional capacity of ⩽ 5 to 6 metabolic equivalents (METS)
• Cardiac pump failure
  • Muscle dysfunction produces moderate-to-severe reduction in CO
  • Marked activity limitation
  • Functional capacity of ⩽ 4 to 5 METS

Imaging2

• Echocardiography
  • Visualization of enlarged mitral leaflets
  • Displacement of leaflets into left atrium during systolic contraction
  • Mitral valve leaflets > 5mm, displacement > 2mm indicates classic MVP
• Chest x-ray
  • Possible enlargement of left atrium or ventricle is concomitant mitral regurgitation (MR)
• ECG
  • Results usually normal
  • Possible biphasic T waves
  • Possible signs of arrhythmias: fibrillation, ...