Table 1.
Effect of extracellular potassium concentration ([K+]o) on resting membrane potential (RMP), threshold potential (TP), and maximum velocity (Vmax) in ventricular muscle fibers of guinea pigs
| [K+]o (mM) |
RMP (mV) |
TP (mV) |
RMP – TP (mV) |
Vmax (V/s) |
|---|---|---|---|---|
| 2.0 | 99.4 | 72.7 | 26.7 | 236 |
| 5.4 | 83.0 | 65.1 | 17.9 | 219 |
| 10.0 | 65.8 | 51.4 | 14.4 | 178 |
| 11.5 | 62.8 | 45.6 | 17.2 | 154 |
| 13.0 | 60.7 | 41.9 | 18.8 | 103 |
| 16.2 | 55.4 | 34.7 | 20.7 | 45 |
Adapted with permission from Kishida H, Surawicz B, Fu LT. Effects of K+ and K+-induced polarization on (dV/dt)max, threshold potential, and membrane input resistance in guinea pig and cat ventricular myocardium. Circ Res. 1979;44:800–814.31