Figure 6.

The E-4031-sensitive current (I_Kr) and the Ba²⁺-sensitive current (I_K1) during action potentials with gradually longer repolarization phase, as recorded in an undiseased human left ventricular myocyte. Transmembrane currents were elicited by applying action potentials as command pulses (top) recorded in previous experiments using conventional microelectrodes at pacing cycle lengths of 400, 700, 1000, 2000, 3000 and 5000 ms. The E-4031-sensitive (I_Kr, left) and the Ba²⁺-sensitive (I_K1 right) currents were recorded as difference currents. I_K1, inward rectifier potassium current; I_Kr, rapid component of the delayed rectifier potassium current.