Tamargo J, Moe B, Moe G K
Circ Res. 1975 Nov;37(5):534-41. doi: 10.1161/01.res.37.5.534.
An ineffective stimulus applied to cardiac tissue within the relative refractory period can alter the response to an immediately subsequent stimulus. We observed three response patterns that can coexist at different sites of stimulation in the same heart. In the first pattern, a stimulus of two to ten times diastolic threshold, applied too early to elicit a propagated response, becomes effective when a stimulus of equal strength is delivered 10 msec earlier. In the second pattern, a stimulus applied just late enough to evoke a response fails to do so when a stimulus of equal strenght precedes it by as much as 30 msec. Finally, in the third pattern, two stimuli, separated by 10 msec, both of which are late enough to be effective when they are given alone, fail to yield a propagated response when they are applied together. These results have a bearing on the use of trains of stimuli to assess the ventricular fibrillation threshold. Possible interpretations are based on the temporal dispersion of recovery from the refractory state.
在相对不应期施加于心脏组织的无效刺激可改变对紧接着的后续刺激的反应。我们观察到三种反应模式，它们可在同一心脏的不同刺激部位共存。在第一种模式中，施加的刺激强度为舒张阈值的两到十倍，施加过早无法引发传播性反应，但当提前10毫秒给予同等强度的刺激时，该刺激就变得有效。在第二种模式中，刚好在足够晚的时候施加的刺激能够引发反应，但当同等强度的刺激在其之前多达30毫秒施加时，该刺激就无法引发反应。最后，在第三种模式中，两个相隔10毫秒的刺激，当单独给予时都足够晚才有效，但当它们一起施加时却无法产生传播性反应。这些结果与使用刺激序列来评估心室颤动阈值有关。可能的解释基于从不应期恢复的时间离散。
