Figure 5. Physiological and drug testing on the cardiac tissues.

Effect of the concentration in extracellular calcium (A), verapamil (B), isoproterenol (C), or dofetilide (D) on tissues contractility: beat rate, contraction stress, and the maximum contraction and relaxation speeds. These parameters are expressed as a ratio between their value for each concentration and the value at basal state ([Ca²⁺]=0.5 mM for calcium test and [Drug]=0 M for drug testing). An ANOVA for repeated measures was carried out for each parameter. For each test, the value of each parameter at each concentration is compared to its value at the minimal concentration of the drug (respectively [Ca²⁺]=0.5 mM, [verapamil]=10⁻⁹ M, [isoproterenol]=10⁻⁹ M, and [dofetilide]=10⁻⁹ M). (E) Poincaré plot for 0 nM, 1 nM, 3 nM, and 7 nM of dofetilide. For each concentration of each drug, more than 20 tissues from three different concentrations could be analyzed. Data is presented as mean ± standard error mean (SEM). *: p<0.05; **: p<0.01; ***: p<0.001; ****: p<0.0001.