Data and statistical analysis
Data are presented as means ± standard error of mean (SEM) of the average of observations over the time course of the experiment. Data were tested for normality using Shapiro-Wilk tests. For multiple (≥3) comparisons, data were compared by one-way analysis of variance followed by a Bonferroni modified t -test, or by Kruskal-Wallis tests if non-normally distributed. Comparisons of two groups of data used either an unpaired t -test for normally distributed data, or a Mann-Whitney U test for skewed data or where there was a significant difference between the variances of each group. Differences between groups in the time to onset of arrhythmias were analysed by log-rank tests. A p-value less than 0.05 was considered statistically significant. The data and statistical analysis comply with the recommendations on experimental design and analysis in pharmacology (Curtis et al., 2018). Statistical analyses were performed using Arcus Pro-Stat version 3.12.