[Auricular and left ventricular compliance in acute and chronic mitral insufficiency].

Left atrial and ventricular compliance has been studied in 25 cases of chronic mitral incompetence (CMI) and 9 cases of acute mitrale incompetence (AMI). Left atrial compliance was evaluated by the ratio between maximal variation in volume and corresponding maximal variation in pressure; it was found to be higher in cases of CMI than in cases of AMI. Left ventricular compliance was evaluated by various indices (Diamond, Mirsky, Gaasch, Laird), and was found to be increased equally in the chronic and acute types. It is possible that an explanation of this increase incompliance is to be found in the rearrangement of myocardial fibres which follows the dilatation. It constitutes a fundamental means of chronic adaptation, and shows that the diastolic elastic properties of the cavities of the atrium and ventricle are as important in the evaluation of mitral incompetence as the properties of systolic contraction.