Fig. 3

Representative MAP recordings from programmed electrical stimulation (PES). Before introduction of heptanol, the S2 extrastimulus failed to induce ventricular tachycardia (VT) (A). In contrast, 120 s after introduction of 2 mM heptanol, the S2 extrastimulus induced VT (B). Incidences of VT in hearts subject to PES before and 120 s after introduction of 0.1, 0.5, 1, and 2 mM heptanol (C). The asterisk indicates that 2 mM heptanol induced significant arrhythmogenic effects (Fisher’s exact test, P < 0.05)