Morady F, Wang Y S, Scheinman M M, Sung R J, Shen E, Shapiro W A
Circulation. 1983 Mar;67(3):646-50. doi: 10.1161/01.cir.67.3.646.
Twenty-one patients with atrioventricular (AV) bypass tracts underwent electrophysiologic studies. The bypass tract was left-sided in 15 patients, septal in five and right-sided in one patient. Orthodromic AV-reciprocating tachycardia was induced in all 21 patients, with a mean tachycardia cycle length of 342 +/- 59 msec. The introduction of single stimuli in the high right atrium during tachycardia resulted in simultaneous dissociation of the high right atrial and low septal atrial electrograms in nine patients. In six patients, high right atrial overdrive pacing during tachycardia resulted in simultaneous dissociation of the high right atrial and low septal atrial electrograms for two to five consecutive beats. All patients in whom the low septal atrial electrogram was dissociated from the tachycardia had a left-sided bypass tract. In no patient was the coronary sinus atrial electrogram dissociated from the tachycardia by high right atrial pacing. Dissociation of the low septal atrial electrogram (as recorded in the His bundle electrogram) from AV-reciprocating tachycardia suggests that the portion of the right atrium adjacent to the AV node may not be a necessary link in the tachycardia circuit. This observation suggests that the site of entry of left-sided impulses into the AV node may be different from that of right-sided impulses.
21例患有房室（AV）旁路传导束的患者接受了电生理研究。15例患者的旁路传导束位于左侧，5例位于间隔部，1例位于右侧。所有21例患者均诱发了顺向性房室折返性心动过速，平均心动过速周期长度为342±59毫秒。心动过速期间在高位右心房引入单个刺激，导致9例患者高位右心房和低位间隔部心房电图同时分离。6例患者在心动过速期间进行高位右心房超速起搏，导致高位右心房和低位间隔部心房电图连续2至5个搏动同时分离。所有低位间隔部心房电图与心动过速分离的患者均有左侧旁路传导束。通过高位右心房起搏，未发现冠状窦心房电图与心动过速分离的患者。低位间隔部心房电图（如希氏束电图所记录）与房室折返性心动过速分离表明，右心房邻近房室结的部分可能不是心动过速环路中的必要环节。这一观察结果提示，左侧冲动进入房室结的部位可能与右侧冲动不同。
