[Experimental and clinical data on the state of the atria in postinfarct cardiosclerosis]

In 16 rabbit experiments with macrofocal postinfarction cardiosclerosis and 8 control intact animals delayed electron microscopy of myocardium portions from the left ventricle and atria was undertaken, and in 76 clinical observations of patients who had survived a myocardial infarction 1 to 10 years before the examination the indices of the haemodynamic and electrical activity of the atria were compared with those of the contractile function of the left ventricular myocardium under bicycle exercise tests of a growing intensity (with the data of the left ventricular ultrastructure--in the experimental cases). The changes in the left atrium were found to be of an adaptational nature, the right atrium entering the pathogenetic chain when the compensatory capacities of the left atrium got exhausted in the course of the disease, this being a prognostically alerting sign.