Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
Heart Rhythm. 2012 Jun;9(6):977-82. doi: 10.1016/j.hrthm.2012.01.021. Epub 2012 Jan 28.
Action potential duration is widely used as a measure of refractory period in ischemia. Although the end of repolarization closely corresponds to the end of refractoriness in the well-perfused, well-oxygenated myocardium, it is no longer true for the ischemic myocardium, in which the recovery of excitability lags behind full repolarization. The purpose the study was to review this phenomenon of postrepolarization refractoriness during ischemia and after application of various antiarrhythmic drugs. The findings showed that although postrepolarization refractoriness is profoundly proarrhythmic during ischemia, it may protect the heart from reentrant arrhythmias in the absence of depolarization of the resting membrane. An increase in postrepolarization refractoriness induced by sodium-channel-blocking drugs may exert an antifibrillatory action.
动作电位时程被广泛用作缺血时不应期的测量指标。虽然在灌注良好、氧合良好的心肌中，复极结束与不应期结束密切对应，但对于缺血心肌来说，这种对应关系不再成立，因为兴奋性的恢复落后于完全复极。本研究的目的是回顾缺血期间和应用各种抗心律失常药物后复极后不应期的这一现象。研究结果表明，尽管复极后不应期在缺血时极易引发心律失常，但在静息膜去极化不存在的情况下，它可能保护心脏免受折返性心律失常的影响。钠通道阻断药物引起的复极后不应期延长可能会发挥抗纤颤作用。
