Immune mechanisms of cardiac disease.

It is evident that cellular infiltration can affect cardiac structure and function in a variety of disease states. Myocardial contractility can be impaired by cell-mediated injury or local release of cytokines. The study of immune cardiac disease has entered a period of rapid expansion that should be characterized by delineation of the mechanisms by which immune cells and factors localize in the myocardium, modulate myocyte function, and remodel myocardial architecture (Fig. 2). This new knowledge should result in the ability to target specifically both the pathways by which cardiac contractility is impaired by chronic inflammation and the sustained immune reactivity to cardiac antigens that underlies chronic myocardial inflammation. Nonspecific therapeutic interventions directed at congestive heart failure, currently the only acceptable approach to the treatment of immune myocarditis, should then serve a more ancillary function in the context of the use of rationally designed drugs. Such drugs could, for example, be specifically targeted to inhibiting the trafficking of leukocytes into the heart or the effects of their subsequent activation within the myocardium.