– VK-II-86 is a carvedilol analogue lacking antagonist activity at ?-adrenoceptors, effectively suppresses SOICR by directly reducing the open duration of the cardiac ryanodine receptor (RyR2).VK-II-86 exhibited >2,000-fold lower beta-AR binding affinity than carvedilol.VK-II-86 prevented stress-induced ventricular tachyarrhythmias in RyR2-mutant mice and did so more effectively when combined with either of the selective beta blockers metoprolol or bisoprolol.VK-II-86 prevented hypokalaemia-induced AP prolongation and depolarization but did not alter AP parameters in normokalaemia.