Clinical study of left atrial compliance and left atrial volume in mitral stenosis.

We studied left atrial compliance and left atrial volume in 21 patients with mitral stenosis showing a normal sinus rhythm. 1) A significant (p less than 0.001) negative linear correlation of r = 0.72 was found between the mitral valve area (MVA) and left atrial mean pressure (LAm). 2) A significant (p less than 0.005) positive linear correlation of r = 0.60 was found between MVA and left atrial compliance (delta V/delta P). 3) A significant (p less than 0.001) hyperbolic correlation of r = 0.73 was found between LAm and delta V/delta P. 4) A significant (p less than 0.001) hyperbolic correlation of r = 0.65 was found between left atrial specific compliance (delta V/delta P/LAVmax. LAVmax: left atrial maximum volume) and left atrial mean volume. 5) These findings led to the conclusion that in patients with mitral stenosis showing a normal sinus rhythm, left atrial compliance was decreased in patients whose left atrial volume was increased, and the decrease of left atrial compliance was related to narrowing of the mitral valve area and elevation of the left atrial pressure.