Toxic cardiomyopathies.

Examples of toxic cardiomyopathies of various characteristics are presented. Daunomycin and doxorubicin, antineoplastic drugs, cause multifocal cardiomyopathies and intractable heart failure by cardiotoxic mechanisms; these effects are delayed and related to the cumulative dose. Cobalt caused diffuse vacuolar cardiomyopathy in chronic beer drinkers. The development of fulminant heart failure was the function of factors that increased the adsorption of cobalt or sensitized the myocardium to its cytotoxic effect. Beta-adrenergic receptor stimulant bronchodilators like isoproterenol or vasodilating antihypersensitive drugs like hydralazine are able to produce focal subendocardial necroses. This lesion is due to ischemia brought about by the acute exxagerated pharmacological effects of these compounds.