Figure 9.
Maximum action potential durations (APD)90 restitution gradients, critical diastolic intervals and maximum APD90 reductions obtained from the (A-C) epicardium and (D-F) endocardium. All three parameters were increased by hypokalaemia (*P<0.05, **P<0.01 and *P<0.05, respectively). Of these, maximum APD90 reductions were restored to normokalaemic values (P>0.05), whereas maximum APD90 restitution gradients and critical diastolic intervals were not further altered by 0.1 or 2 mM heptanol. All three parameters obtained from the endocardium were unaltered by hypokalaemia whether prior and subsequent to the introduction of 0.1 or 2 mM heptanol (P>0.05 in all cases). (†P<0.05).