Figure 1. Conventional whole cell patch clamp view of I_to: theoretically predicted kinetic behaviour of I_to,fast during a ventricular action potential.

The illustrated action potential was recorded from a ferret right ventricular myocyte (22°C), while the corresponding I_to,fast waveform was generated using the recorded action potential waveform as the voltage ‘driving function’ for the I_to,fast gating equations developed by Campbell et al. (1993a, b). Such predicted behaviour may only reflect the kinetics of I_to,fast under ‘basal’ conditions, i.e. in the absence of normal [Ca²⁺]_i transients and minimal kinase-mediated regulation. Figure reproduced from Campbell et al. (1995) with permission from Elsevier.