Malik M, Camm A J
Department of Cardiological Sciences, St. George's Hospital Medical School, London, U.K.
Int J Biomed Comput. 1991 Oct;29(1):7-21. doi: 10.1016/0020-7101(91)90009-4.
The study used a computer model of cardiac excitation to reproduce atrioventricular (AV) reentrant tachycardia and to evaluate the possibility of its termination by overdrive burst pacing. The model simulated activation waves radiating along a one-dimensional circular pathway, the portions of which represented the atrial, AV nodal, His-Purkinje, ventricular, and bypass parts of the tachycardia circuit. The pathway consisted of 289 elements. Only depolarised and resting states of elements were modelled. Differential refractoriness and conduction velocity for each element and the cycle length dependence of AV nodal decremental conduction were introduced. The experiments with the model examined the ability of overdrive 'on-circuit' pacing to terminate the tachycardia in order to determine the relevance of: (a) the coupling interval of the first beat in the burst; (b) the cycle length of the burst; (c) the number of stimuli in the burst; (d) His-Purkinje refractoriness; and (e) the degree of AV nodal decremental conduction. The results suggested that: (A) the general impression of a regular recovery wave and of a regular excitable window moving uniformly along the macro-reentrant circular path is incorrect; (B) the use of overdrive bursts of several stimuli with a short coupling interval has unpredictable effects; (C) the use of faster bursts with a cycle length only slightly shorter than the tachycardia cycle length is more safe (with respect to tachycardia reinitiation) and for certain combinations of the coupling interval and cycle length, prolonged bursts do not reinitiate the tachycardia; (D) the likelihood of tachycardia termination is increased by prolonging the refractoriness of the tachycardia circuit and by reducing AV nodal decremental conduction.
该研究使用心脏兴奋的计算机模型来重现房室（AV）折返性心动过速，并评估超速猝发起搏终止该心动过速的可能性。该模型模拟了沿一维圆形路径辐射的激活波，其各部分代表心动过速环路的心房、房室结、希氏-浦肯野、心室和旁路部分。该路径由289个元件组成。仅对元件的去极化和静息状态进行建模。引入了每个元件的差异不应期和传导速度以及房室结递减传导的周期长度依赖性。该模型的实验研究了超速“在线”起搏终止心动过速的能力，以确定以下因素的相关性：（a）猝发中第一个搏动的耦合间期；（b）猝发的周期长度；（c）猝发中的刺激次数；（d）希氏-浦肯野不应期；以及（e）房室结递减传导的程度。结果表明：（A）关于规则恢复波和规则可兴奋窗沿大折返圆形路径均匀移动的总体印象是不正确的；（B）使用具有短耦合间期的多个刺激的超速猝发具有不可预测的效果；（C）使用周期长度仅略短于心动过速周期长度的更快猝发更安全（就心动过速重新起始而言），并且对于耦合间期和周期长度的某些组合，延长的猝发不会重新引发心动过速；（D）延长心动过速环路的不应期和减少房室结递减传导可增加心动过速终止的可能性。
