Figure 5.

Treatment of chronically infected mice with anakinra (IL-1R antagonist) does not reverse arrhythmias. Wild-type (WT) (C57BL/6 background) were infected with the Colombian strain of T. cruzi (100 parasites) at 270 dpi and treated with an IL-1R antagonist, anakinra (10 mg/kg, i.p.), daily for 30 days. (A) Representative EKG tracings; (B) heart rate, P wave, PR interval, and QJ interval duration (9–22 mice per group, data represent the mean ± SEM). (C) Identified arrhythmic events. (D) Representative whole heart AP traces; (E) whole heart AP duration at 30%, 50%, 70%, and 90% of repolarization (4–14 mice per group). (F) Incidence of triggering activity among hearts from groups of mice upon S₁–S₂ protocol; (G) representative tracing showing triggering activity in a Tc+AK heart. NI, noninfected; Tc, chronically infected mice; Tc+AK, chronically infected mice treated with anakinra.