Table 1.
Average rc of cellular components
| Components | SA node depolarization | SA node repolarization | Ventricular repolarization |
|---|---|---|---|
| p(o) of ion channels | |||
| INa | 0.0009 | 0.0001 | 0.0124 |
| ICaL | 0.1615 | 0.5798 | 0.8729 |
| ICaT | 0.0082 | 0.0008 | −0.0003 |
| Ist | 0.3746 | 0.1261 | — |
| Iha | 0.0520 | −0.0038 | — |
| IK1 | 0.0106 | 0.0011 | 0.2419 |
| IKr | 0.5925 | 0.2673 | 0.0261 |
| IKs | 0.0186 | 0.0868 | 0.0814 |
| Ito | — | — | −0.0045 |
| IKpl | −0.0124 | −0.0684 | −0.0012 |
| Il(Ca) | −0.0047 | 0.0143 | 0.0073 |
| IKATP | ∼0∗ | ∼0∗ | ∼0∗ |
| IKACh | 0.0058 | 0.0151 | — |
| IVRCC | — | — | -0.0008 |
| ICFTR | — | — | 0 |
| Turnover rate of transporters | |||
| INaCa | −0.1519 | 0.0087 | −0.1264 |
| INaK | −0.0603 | −0.0170 | −0.0009 |
| IPMCA | 0.0040 | ∼0 | −0.0012 |
| EXand f′(Vm) | |||
| K+ flux | −0.0050 | 0.0313 | 0.0103 |
| Na+ flux | 0.0053 | −0.0137 | −0.0059 |
| Ca+ flux | 0.0004 | −0.0286 | −0.1122 |
| Cl− flux | ∼0∗ | ∼0∗ | 0.0011 |
| Sum | 1 | 1 | 1 |
The rc for p(o) of nongating currents, IbNSC, IClb, or ICab, is zero. Abbreviations for currents: INa, Na+ current; ICaL, L-type Ca2+ current; ICaT, T-type Ca2+ current; Ist, sustained inward current; Iha, hyperpolarization-activated cation current; IK1, inward rectifier K+ current; IKr, delayed rectifier K+ current, rapid component; IKs, delayed rectifier K+ current, slow component; Ito, transient outward current; IKpl, voltage-dependent K+ current (plateau current); Il(Ca), Ca2+-activated background cation current; IKATP, ATP-sensitive K+ current; IKACh, Acetylcholine-activated K+ current; IVRCC, volume-regulated Cl− channel current; INaCa, Na+/Ca2+ exchange current; INaK, Na+/K+ pump current; IPMCA, plasma membrane Ca2+-ATPase current; IbNSC, background nonselective cation current; IClb, background Cl− current; ICab, background Ca2+ current; ICFTR, cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel current.
rc < 10−4.