Figure 2.

APD₉₀ alternans amplitudes. Amplitudes of APD₉₀ alternans obtained at a range of BCLs during a dynamic pacing protocol from the (A-C) epicardium under control and hypokalaemic conditions prior and subsequent to the introduction of 0.1 mM heptanol, and from the (D-F) endocardium under the same conditions. The amplitudes of epicardial APD₉₀ alternans were significantly increased by hypokalaemia at BCLs ≤65 msec (analysis of variance, P<0.05) and not altered further by 0.1 mM heptanol (P>0.05). By contrast, mp significant difference was observed for those of endocardial APD₉₀ alternans between these conditions (P>0.05). APD, action potential duration; BCL, basic cycle length.