Hemodynamic characterization of left ventricular function in experimental coxsackieviral myocarditis: effects of carvedilol and metoprolol.

摘要

Background: Carvedilol, a vasodilating nonselective beta-adrenoceptor antagonist, but not metoprolol, a selective beta(1)-adrenoceptor antagonist, has been shown to increase the production of cardiac antiinflammatory cytokines in experimental myocarditis. However, the hemodynamic consequences of these differences had not been investigated until today. Therefore, we determined the effects of carvedilol and metoprolol on left ventricular function in a murine model of coxsackievirus B3 (CVB3)-induced myocarditis. Methods: BALB/c mice were inoculated with the coxsackie-B3 virus. Four and 10 days after infection, left ventricular function was investigated using a conductance micromanometer system. Additional groups were treated starting 24 h after infection using equipotent doses of carvedilol and metoprolol and studied on day 10. Results: On day 4, infected mice manifested increased afterload-enhanced contractility and abnormal diastolic function. On day 10, contractile function of untreated mice was impaired. Carvedilol significantly improved cardiac index and most systolic indices, whereas metoprolol was substantially less effective. Diastolic dysfunction was not influenced by either of the beta-adrenoceptor antagonists. Conclusions: These hemodynamic data indicate that not only beta(1)-adrenoceptor blockade but also pleiotropic effects are involved in the cardioprotective effects of carvedilol on the pathophysiology of acute viral myocarditis.