Fig. 5.

Representative whole cell current recordings from an Epi (A) and Endo (B) left ventricular (LV) myocyte. Current recordings were obtained at test potentials between −80 and 10 mV in 5-mV increments from a holding potential (HP) of −120 mV. C: current-voltage (I-V) relations for Epi (n = 14) and Endo (n = 15) cells showing no differences in current density. D: steady-state activation relations for Epi and Endo. Chord conductance was determined using the ratio of current to the electromotive potential for the cells shown in C. Data were normalized and plotted against their test potential.