Fig. 2.

Snapshots of the propagation of an action potential across similar sized regions of tissue in rabbit (left) and alligator (right) at 38°C (top) and 23°C (bottom). The difference in wave propagation between temperatures is nearly indistinguishable in the alligator heart, whereas the rabbit heart displays a clear CV reduction in hypothermia. The wavefront of excitation in the alligator is not as discernible as in the rabbit due to a nearly order of magnitude longer depolarization, which results in a “smearing” of the action potential’s wavefront over the alligator’s heart.