Figure 7. I _Ks is not responsible for AP triangulation in males.

A, representative V _m traces, APD₂₅, APD₈₀ and APD₈₀ − APD₂₅ maps at baseline, after pretreatment with 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, compared with baseline, chromanol 293B markedly prolonged APD₂₅ and APD₈₀ but more prominently APD₈₀. With chromanol 293B pretreatment, isoproterenol still shortened and triangulated AP. C, apamin only minimally prolonged APD₂₅ and APD₈₀. D, compared with females, males had significant larger response in chromanol 293B‐induced APD prolongation (by unpaired t test). [Color figure can be viewed at http://wileyonlinelibrary.com]