Penny W J, Sheridan D J
Cardiovasc Res. 1983 Jun;17(6):363-72. doi: 10.1093/cvr/17.6.363.
Action potentials and ECGs were recorded from isolated guinea pig hearts during low flow (10% of control) and zero flow myocardial "ischaemia" and during subsequent reperfusion. During myocardial "ischaemia" ventricular tachycardia and ventricular fibrillation were significantly more frequent during low flow, than zero flow "ischaemia" (P less than 0.01). Reperfusion arrhythmias required a minimum ischaemic period of 10 to 15 min, were most frequent following 20 to 30 min of "ischaemia", being fewer following 60 min of "ischaemia" (P less than 0.05). The degree of "ischaemia" had little effect on reperfusion arrhythmias following 20 to 30 min of "ischaemia". Both types of "ischaemia" reduced action potential amplitude, Vmax, and duration, and increased conduction time. During low flow "ischaemia", electrophysiological change reached a nadir at 12 +/- 3 (mean +/- SEM) min, and in all cases spontaneous electrophysiological recovery in action potentials and conduction time preceded ventricular arrhythmias, which occurred at 18 +/- 3 min. In contrast during zero flow "ischaemia" electrophysiological changes were more marked and no recovery was observed. Refractory periods were initially prolonged by both forms of "ischaemia", followed by a marked shortening. The initial prolongation was more marked and subsequent shortening less during zero than low flow "ischaemia". Reperfusion induced electrophysiological recovery in all hearts; however reperfusion VF was preceded by further shortening of action potential duration and refractory period. These results indicate that residual flow during myocardial "ischaemia" is associated with spontaneous electrophysiological recovery and more frequent ventricular arrhythmias. The severity of "ischaemia" is less important than its duration for the development of reperfusion arrhythmias.
在低流量（对照的10%）和零流量心肌“缺血”期间以及随后的再灌注过程中，记录了分离的豚鼠心脏的动作电位和心电图。在心肌“缺血”期间，低流量时室性心动过速和心室颤动的发生频率显著高于零流量“缺血”（P<0.01）。再灌注心律失常需要至少10至15分钟的缺血期，在“缺血”20至30分钟后最为频繁，在“缺血”60分钟后则较少（P<0.05）。“缺血”程度对“缺血”20至30分钟后的再灌注心律失常影响较小。两种类型的“缺血”均降低了动作电位幅度、Vmax和时程，并延长了传导时间。在低流量“缺血”期间，电生理变化在12±3（均值±标准误）分钟时达到最低点，在所有情况下，动作电位和传导时间的自发电生理恢复先于心室心律失常，后者发生在18±3分钟。相比之下，在零流量“缺血”期间，电生理变化更为明显，未观察到恢复。不应期最初在两种形式的“缺血”时均延长，随后显著缩短。与低流量“缺血”相比，零流量“缺血”时最初的延长更为明显，随后的缩短则较少。再灌注使所有心脏的电生理恢复；然而，再灌注室颤之前动作电位时程和不应期会进一步缩短。这些结果表明，心肌“缺血”期间的残余血流与自发电生理恢复和更频繁的心室心律失常有关。对于再灌注心律失常的发生，“缺血”的严重程度不如其持续时间重要。
