Last reviewed 01/2018

There are two major haemodynamic disorders in patients with mitral stenosis:

  • raised left atrial pressure:
    • is not significant until the valve area is less than 25% of normal (1.0 - 1.5 cm sq.)
    • causes an increase in left atrial pressure and a diastolic gradient across the mitral valve
    • as the pulmonary venous pressure increases, exudation of fluid causes pulmonary oedema with a corresponding rise in pulmonary arterial pressure

  • pulmonary hypertension:
    • is the result of the long-term increase in left atrial pressure which causes a rise in pulmonary vascular resistance
    • is accompanied by intimal and medial thickening of the pulmonary vasculature
    • is prominent if the left atrium is small and indistensible

Cardiac output diminishes, especially when dilatation of the right ventricle and tricuspid ring causes tricuspid regurgitation.