Table 1.
Action potential characteristics of SA node cells with and without ICl(Ca)
| No ICl(Ca) (n = 14) | With ICl(Ca) (n = 7) | |
|---|---|---|
| APD20 (ms) | 63 ± 11 | 70 ± 7 |
| APD50 (ms) | 92 ± 12 | 102 ± 10 |
| APD100 (ms) | 167 ± 17 | 171 ± 18 |
| MDP (mV) | −61.0 ± 1.6 | −60.4 ± 3.2 |
| DDR (mVs−1) | 92 ± 12 | 91 ± 18 |
| Overshoot (mV) | 23.3 ± 1.6 | 20.9 ± 2.9 |
| dV/dtmax (V s−1) | 5.9 ± 1.3 | 5.1 ± 1.5 |
| Cycle length (ms) | 316 ± 31 | 314 ± 38 |
| Capacitance (pF) | 49 ± 6 | 47 ± 10 |
Data are means ± s.e.m. APD20, APD50 and APD100,action potential duration at 20, 50 and 100% repolarization, respectively. MDP, maximal diastolic potential; DDR,diastolic depolarization rate; Overshoot,action potential overshoot and dV/dtmax, maximum upstroke velocity.