Figure 5.

Increased BVR precedes EAD generation. (A) Representative example of repolarization variability by I_Kr block without EAD generation, compared to baseline (green trace). (B) Poincaré plot of APD₉₀ of the same cell as in panel (A). (C) Representative example of repolarization variability by dofetilide, compared to baseline (green trace; note the different time axis), in a cell that eventually generated an EAD (indicated by the symbol Φ). (D) Poincaré plot of APD₉₀ of the same cell as in panel (C) before the very first EAD recorded. (E) Average APD in cells that developed EADs (n = 10) or did not (n = 10). (F) Average BVR (prior to first EAD, if any) in cells that developed EADs (n = 10) or did not (n = 10).