Figure 1.

Modelling the influence of action potential duration on the electrical restitution curve. (A) Data demonstrating that mono-phasic action potential duration (APD₉₀) is related in a non-linear manner to the average rate of repolarization (R_Repol) in isolated guinea pig hearts. (B) The same relationship is shown in microelectrode recordings from isolated ventricular myocytes. Data represent mean ± SEM at each pacing cycle length. (C) The non-linear relation between the average R_Repol and APD predicts that prolongation of the action potential will act to steepen the restitution curve (see text for details). Panel C adapted with permissions from Winter and Shattock (2016).²⁵