In experiments on rats it is fixed, that at hemodinamic pulmonary edema the ultrastructure of cardiomyocytes of auricles changes, which consists in decrease of quantity of secretory granules, which produce a natriuretic factor. Such changes of ultrastructure of cardiomyocytes can be regarded as a compensatory mechanism, which arises at hemodinamic pulmonary edema for maintenance of adequate hemodynamics in the lesser circulation.