**Abstract**

The review considers changes in the pumping and contractile function of the heart in three types of cardiomyopathies. Isoproterenol cardiomyopathy is closest to ischemic cardiomyopathy, which is most commonly observed in the clinic. Cardiomyopathy caused by chronic administration of doxorubicin represents the closest to the clinic variant of toxic cardiomyopathy. Diabetic cardiomyopathy is increasingly common in our time; the review will consider information about type 1 diabetes. The greatest attention in the review is paid to diastolic dysfunction of the heart, the main causes of its occurrence and compensatory mechanisms are analyzed. The earliest changes in diastolic dysfunction in these types of cardiomyopathies are a slowdown in myocardial relaxation and endothelial dysfunction. Information is given showing that the basis of delayed relaxation is two reasons—impaired transport of Ca++ in cardiomyocytes and altered properties of connectin (titin). The ability of mitochondrial oriented antioxidants to prevent cardiac dysfunction caused by doxorubicin has been demonstrated.

**Keywords:** heart, myocardium, diastolic dysfunction, contractility, relaxability, distensibility, contractile function, Ca++ transport, connectin (titin), isoproterenol, doxorubicin, diabetes, vascular tone
