Figure 5.

Effect of the ATP-sensitive K channel agonist pinacidil in neonatal rat ventricular myocyte monolayers with complex sustained early afterdepolarization-mediated arrhythmias. A: Snapshots of voltage fluorescence (F_V) at the times indicated in a monolayer with a central obstacle in which BayK4688 + isoproterenol induced an arrhythmia driven primarily by functional rotors (spiral waves) at 6 and 8 o’clock (left panels). Pinacidil (100 μM, right panels) accelerated but did not significantly affect the complexity of the arrhythmia. B: Voltage snapshots from another monolayer with a central obstacle, in which pinacidil (right panels) increased the complexity of the BayK4688 + isoproterenol-induced arrhythmia, as evident from the greater number of wave fronts. F_V gray scale as described in Figure 1 legend.