Figure 3.

(A) Epicardial activation latency and (B) conduction velocity (CV), and (C) endocardial activation latency obtained during regular 8 Hz pacing. These were not altered by hypokalaemia whether prior or subsequent to introduction of 0.1 mM heptanol (analysis of variance, P>0.05). By contrast, epicardial (***P<0.001) and endocardial (*P<0.05) activation latencies were significantly increased by 2 mM heptanol, corresponding to reduced CVs (***P<0.001). The epicardial activation latencies were not significantly different from the corresponding endocardial activation latencies under all pharmacological conditions studied (P>0.05).