[Angiocardiographic evaluation of left atrial volume in patients with mitral valve defect].

The cine- and angiocardiographic method permits a quantitative evaluation of the left atrial volume. The maximum volume of the left atrium was found to increase along with the enhancement of mitral regurgitation. Mitral insufficiency is not always accompanied by a "systolic expansion" of the left atrium. The size of the left atrium chamber is mainly determined by the state of the myocardium, and does not much depend on the elevation of the intra-atrial pressure. In cases of mitral defects the increase of the left atrial volume and the changes in the pulse gradient of the left atrial volumes are a compensatory mechanism in the work of the left atrium.