Determinants of Beat-to-Beat Variability of Repolarization Duration in the Canine Ventricular Myocyte: A Computational Analysis
Figure 4
Effect of AP morphology on BVR.
A. Overlay of 30 APs (top panel) and Poincaré plot of corresponding APDs (bottom panel) for the control myocyte, without alterations in ion currents, simulated with deterministic ICaL, IK1, IKur, and ITo and stochastic gating of the remaining 9 currents. APs with the shortest and longest duration are shown in black, others in grey. Average APD and STV are indicated below the APs. B. Similar to panel A for a triangular AP morphology obtained by reducing IK1 and ITo (by 70% and 60%, respectively) and increasing IKur (by 275%). C. Similar to panels A and B for a square AP morphology obtained by increasing IK1 and IKur (by 20% each) and decreasing ICaL and ITo (by 75% and 20%), respectively.