Statistical Analysis

Data are expressed as means ± SEM. Graph-Pad Prism software (Graph Pad Software, San Diego, California, United States) was used for statistical analysis. Multiple-group comparisons were performed by regular two-way analysis of variance followed by Tukey’s post hoc test as appropriate. The incidence of tachycardia and fibrillation was examined by Fischer’s exact test. One-way ANOVA or ANOVA for repeated measurements with Student-Neumann-Keuls test was performed in normally distributed variables. Differences in arrhythmias among the groups were compared by the Kruskal–Wallis nonparametric test. Values exceeding the 95% probability limits (p < 0.05) were considered statistically significant. The data that were not normally distributed (arrhythmias) were expressed as median_interquartile range.