GS967,

Details:

GS967 is a novel, potent, and selective inhibitor of cardiac late sodium current(late INa); inhibits ATX-II-induced late I(Na) in ventricular myocytes and isolated hearts with IC(50) values of 0.13 and 0.21 μM, respectively.
IC50 value:
Target: late INa inhibitor
in vitro: Reduction of peak I(Na) by GS967 was minimal at a holding potential of -120 mV but increased at -80 mV. GS967 did not prolong action potential duration or the QRS interval. GS967 prevented and reversed proarrhythmic effects (afterdepolarizations and torsades de pointes) of the late I(Na) enhancer ATX-II and the I(Kr) inhibitor E-4031 in isolated ventricular myocytes and hearts [1].
in vivo: GS967 significantly attenuated the proarrhythmic effects of methoxamine+clofilium and suppressed ischemia-induced arrhythmias. GS967 was more potent and effective to reduce late I(Na) and arrhythmias than either flecainide or ranolazine [1]. In PFs, GS967 (10-300 nM) caused a significant concentration-dependent reduction in action potential duration without altering the maximum rate of rise of the action potential upstroke, action potential amplitude, or resting membrane potential at any rate studied (basic cycle lengths of 1000, 500, and 300 ms) or concentration evaluated (n = 5; P < .05) [2]. GS967 prevented ischemia-induced increases in alternans in the left atrium (19.3 ± 5.6 μV vs 58.3 ± 11.3 μV; P = .023) and left ventricle (217.9 ± 95.8 μV vs 349.3 ± 103.8 μV; P < .001) (n = 7). GS967 reduced ischemia-induced increases in depolarization heterogeneity (atrium: from 45% to 28%; ventricle: from 92% to 51%) and repolarization heterogeneity (atrium: 43% to 23%; ventricle: 137% to 91%). GS967 did not alter heart rate, arterial blood pressure, PR and QT intervals [3].