Effects of carvedilol on viral myocarditis. a: The survival rate in CVB3-inoculated mice followed for 14 days (n = 30 in each group). Carvedilol significantly increased the survival rate in CVB3 infected mice compared to the myocarditis group (P < 0.05). b: HW/BW ratio (n = 8 in each group); c: Histopathological score of cellular infiltration (n = 8 in each group); d: Histopathological score of myocardial necrosis (n = 8 in each group); e: Total cardiac collagen volume fraction on day 14 (n = 8 in each group). ND, not detected. Control, normal mice treated with normal saline solution; Myocarditis, infected mice treated with normal saline solution; Carvedilol, infected mice treated with carvedilol.