Table 2.
Action potential parameters of control and RA-treated hiPSC-CMs, stimulated at an overdrive frequency of 1 Hz, in the absence or presence of IK1 injection.
| Action Potential Parameter | CTRL (n = 13) | RA (n = 18) | ||
|---|---|---|---|---|
| without IK1 | with IK1 | without IK1 | with IK1 | |
| MDP (mV) | −67.7 ± 1.6 | −83.3 ± 0.5 † | −70.0 ± 1.4 | −82.1 ± 0.4 † |
| Vmax (V/s) | 78.8 ± 23.4 | 233.8 ± 24.5 † | 70.7 ± 17.7 | 218.3 ± 24.8 † |
| APA (mV) | 99.0 ± 3.9 | 121.9 ± 1.5 † | 84.6 ± 4.5 * | 109.2 ± 3.6 * † |
| AP plateau (mV) | 94.2 ± 4.2 | 113.5 ± 2.3 † | 63.1 ± 6.3 * | 75.0 ± 7.6 * † |
| APD20 (ms) | 74.4 ± 11.4 | 85.5 ± 12.1 † | 27.4 ± 5.5 * | 28.6 ± 7.9 * |
| APD50 (ms) | 116.8 ± 16.4 | 139.6 ± 16.9 † | 50.9 ± 8.4 * | 55.5 ± 11.7 * |
| APD90 (ms) | 151.0 ± 17.8 | 168.0 ± 16.9 † | 102.6 ± 10.2 * | 83.4 ± 11.9 * |
Data are mean ± SEM. CTRL: control cells; RA: retinoic acid-treated cells; n: number of cells; MDP: maximum diastolic potential; Vmax: maximum upstroke velocity; APA: action potential amplitude; AP plateau: AP plateau amplitude; APD20, APD50, and APD90: action potential duration at 20%, 50%, and 90% repolarisation, respectively. * p < 0.05 RA vs. CTRL. † p < 0.05 with vs. without IK1 injection.