Fig. 1. Effects of sevoflurane on action potentials recorded from single guinea pig myocytes. (  A ) Action potential waveforms in the absence and presence of 0.3 and 0.5 mm sevoflurane and after washout of the drug are shown. (  B ) Effects of sevoflurane on action potential duration (APD). Dose–response relations for the lengthening of the action potential at 50% and 90% repolarization (APD⁵⁰and APD⁹⁰, respectively) are illustrated. * (APD⁹⁰), # (APD⁵⁰) significantly different from corresponding control values (  P < 0.05).  Error bars denote SEM (n = 6).