Effect of KN-93 on the development of arrhythmias in vivo in WT and JKO mice, upon acute catecholaminergic stress, induced by caffeine/epinephrine. A–B) Percentage of different types of VT (A) and of PVCs-Bigeminy (B) induced by caffeine/epinephrine in WT and JKO mice, either mock-treated (DMSO-control) or pre-treated with KN-93. Data shown are from N=10–13 mice per group. Statistical analysis was performed with the x2 test and symbols represent statistical significant differences (p<0.05) between WT/JKO (*), and JKO/JKO+KN-93 (†). C). Representative ECGs in WT and JKO mice, after Caffeine/Epinephrine administration in mock-treated mice (left panel), or in mice pre-treated with KN-93 (right panel).