起源于房室连接处的异位冲动(Junctional ectopic impulses,JEI)具有双向传导作用,既能逆向传导至心房,引起逆行P波,又能前向传导至心室,产生类似窦性下传的QRS波。然而,有时JEI发出后产生双向性传导阻滞,既不能前向传导激动心室,也不能逆向传导激动心房,而在房室连接处内呈隐匿性传导时,体衷心电图中便无P′-QRS-T波群出现,但JEI确已激动了部分房室连接组织产生1次新的不应期,可影响下一次窦性搏动的传导而引起种种心律紊乱。 JEI能否传导,主要取决于联律间期(R-R′或H-H′)和前一心动周期(R-R间期或 Junctional ectopic impulses (JEIs), which originate in the junction of atrioventricular compartments, have a bidirectional conduction effect, which can reversely transmit to the atria, cause retrograde P wave and transmit forward to the ventricle to generate sinusoidal QRS wave. However, sometimes after the release of JEI bidirectional conduction block, both can not lead to the activation of the ventricular anterior ventricular conduction can not reverse the activation of the atria, and in the atrioventricular junction was occult conduction, since there is no P-ECG, QRS-T wave group appeared, but JEI really excited part of the atrioventricular tissue produced a new refractory period, can affect the next sinus beating conduction caused by a variety of heart rhythm disorders. JEI can conduction, mainly depends on the inter-law interval (R-R ’or H-H’) and the previous cardiac cycle (R-R interval or