Mitral Valve Prolapse

Mitral valve prolapse (MVP) is systolic displacement of one or both mitral leaflets by more than 2 mm above the annular plane into the left atrium.

Prevalence about 2 to 3%. Barlow disease (diffuse myxomatous thickening, redundant leaflets) versus fibroelastic deficiency (isolated segment, usually P2 flail).

Associations: Marfan syndrome, Ehlers Danlos syndrome, Loeys Dietz syndrome, pectus excavatum, straight back syndrome, FLNC and DCHS1 variants, arrhythmic MVP syndrome.

Complications: mitral regurgitation, chordal rupture, endocarditis, atrial fibrillation, ventricular arrhythmia, sudden death (annual risk 0.2 to 0.4% in arrhythmic MVP with mitral annular disjunction), embolism.

• Most patients asymptomatic.
• Palpitations, atypical chest pain, dyspnoea, fatigue, anxiety, presyncope.
• Mid systolic click with late systolic murmur; click earlier with standing or Valsalva, delayed with squatting.
• Holosystolic murmur when significant regurgitation.
• Syncope or sudden cardiac arrest in arrhythmic MVP.

• Echocardiography: leaflet displacement over 2 mm in the long axis parasternal view, leaflet thickness over 5 mm in classic MVP, regurgitation severity, flail segment, mitral annular disjunction, left atrial and ventricular size.
• Cardiac MRI: mitral annular disjunction, late gadolinium enhancement in papillary muscles and inferobasal wall (arrhythmic substrate).
• ECG: inferior T wave inversion, ventricular ectopy (right bundle branch block morphology from papillary muscles); Holter or event monitoring.
• Genetic screening where syndromic features exist.
• Risk markers for arrhythmic events: bileaflet prolapse, annular disjunction, T inversion inferiorly, complex ventricular ectopy, late gadolinium enhancement, female sex, young age.

• Reassurance for asymptomatic uncomplicated MVP; advise normal activity. Baseline echo and repeat every 3 to 5 years (annually if moderate or more regurgitation).
• Palpitations: beta blocker (metoprolol 25 to 100 mg daily, propranolol), reduce caffeine and stimulants.
• Antiarrhythmic therapy, ablation or ICD for high risk malignant arrhythmic MVP (survivors of cardiac arrest or sustained VT).
• Atrial fibrillation: anticoagulation by risk score; stroke prevention.
• Severe regurgitation: surgical repair when indicated (see mitral regurgitation article); transcatheter repair for high risk patients.
• Endocarditis prophylaxis is not recommended except for prior endocarditis or prosthetic material.
• Aspirin 75 to 100 mg for unexplained TIA in sinus rhythm.
• Pregnancy is generally well tolerated.