Figure 4

DI treatment abrogates the gradient in APD. ( A) Representative APs and corresponding AP-induced Ca²⁺ currents recorded from endo- and epicardial myocytes incubated for 24 h under control conditions (blue) and with DI (green). APs were elicited by a train of suprathreshold depolarizing current injections at a basic cycle length of 1,000 ms. (B) Average APD at repolarization to 0 mV (APD_0mV). (C) Average APD at 90% repolarization (APD₉₀). (D) Average peak Ca²⁺ influx (I_Peak) and (E) average total AP-induced Ca²⁺ influx (Q_Ca) obtained from similar recordings to those shown in ( A). Numbers in bars indicate number of myocytes in each group.