F 15845 is a blocker of the persistent sodium current prevents consequences of hypoxia in rat femoral artery. F15845 has been shown to selectively inhibit the persistent sodium current of Nav1.5[1] exerting cardioprotective effects following ischemia. In vitro testing showed minimal effects of F15845 on other important ion channels of the heart, including major Ca2+ and K+ channels.[1] This characteristic is thought to account for the limited effect of F15845 to change other heart parameters such as basal cardiac function, hemodynamic functions and ventricular fibrillation. F15845 was also shown to exert improved effects when the membrane potential was depolarized,[1] by acting on the extracellular side of the channel.