近年来的工作表明,在某些实验条件下,当心肌膜电位因部分除极而导致i_(Na)部分或完全失活时,工作细胞亦可发生类似起搏细胞的节律性活动(RA)。这种低膜电位水平RA的发生很可能是某些室性心律失常形成的基础。我们曾经报道,用持续电刺激,可在经长时间低温处理(24小时以上)后的猪心室肌标本上诱发出这种RA,并提示Na-K泵在其发生 In recent years, the work shows that in some experimental conditions, when the myocardial membrane potential due to partial depolarization caused i_ (Na) partially or completely inactivated, working cells can also occur in pacemaker-like rhythmic activity (RA) . This low membrane potential level of occurrence of RA is likely to be the basis for the formation of certain ventricular arrhythmias. We have reported that with continuous electrical stimulation, this RA can be induced on porcine ventricular myocytes after a prolonged period of cryogenic treatment (more than 24 hours) and suggests that Na-K pumps are responsible for their occurrence