Figure 5. I _Ks is not responsible for AP triangulation in females.

A, representative V _m traces, APD₂₅, APD₈₀ and APD₈₀ − APD₂₅ maps at baseline, after pretreatment of I _Ks blocker chromanol 293B, after isoproterenol, after apamin and after washout (Protocol III). Representative V _m traces were obtained at the LV base. B, D and E, compared with baseline, chromanol 293B prolonged APD₂₅ and APD₈₀ (B), but more prominently APD₈₀ (D), by markedly slowing repolarization at phase 3 (APD₈₀ − APD₂₅; E). With chromanol 293B pretreatment, isoproterenol still shortened and triangulated AP. C, F and G, apamin prolonged APD₂₅ and APD₈₀ (C and F) but more prominently APD₂₅ than APD₈₀ (G). Student's paired t tests were performed in D–G. [Color figure can be viewed at http://wileyonlinelibrary.com]