Differences in the pools of 10 cytokine were found in blood samples from the caudal vein of mice with normal and abnormal heart rhythm. Both groups were albino mice bred by us and differing from mdx albino mice by the absence of mutation in muscular dystrophin gene. Mice with normal heart rhythm had low IL-17 content and elevated concentrations of proinflammatory cytokines IL-6 and IL-1α in comparison with the normal (according to published data). In mice with bradyarrhythmias, increased blood levels of IL-10, IL-6, IL-5, IL-2, IL-1α, IL-17, IL-4, TNF-α, and granulocyte-macrophage colony-stimulating factor were detected. The relative content of IL-4 and IL-17 in the total cytokine pool increased. The lifespan of mice with bradyarrhythmias and cytokine hyperexpression was shorter by 2-3 months in comparison with mice without heart rhythm disturbances and moderate changes in the cytokine pool.