Epidemiology

Etiology

• Most commonly due to rheumatic fever
• Calcification of the mitral valve annulus
• Degenerative aortic stenosis
  • Degenerative calcific deposits most commonly develop in the mitral valve annulus in women over age 60 and generally do not impair valve function.

Pathophysiology

Clinical features

• Auscultation
  • Diastolic murmur heard best at the 5th left intercostal space at the midclavicular line (the apex)
  • Loud first heart sound (S1)
  • Opening snap
    • A high frequency, early to middiastolic sound, heard after S2
    • Occurs when mitral leaflet motion suddenly stops during diastole because the stenosed valve has reached its maximum opening
  • A shorter interval between S2 and opening snap indicates more severe disease; occurs because left atrial pressure is greater than left ventricular end-diastolic pressure (LVEDP).
    • Isovolumetric relaxation phase takes shorter to reach equal pressure with atrium.

Diagnostics

Treatment