Ayusawa M, Sakurada H, Hiyoshi Y, Sumitomo N, Okazaki H, Motomiya T, Sugiura M, Hiraoka M
Department of Cardiology, Tokyo Hiroo Metropolitan Hospital, Japan.
J Electrocardiol. 1998 Jan;31(1):61-5. doi: 10.1016/s0022-0736(98)90009-7.
A 52-year-old woman exhibited Mobitz type II atrioventricular block with right bundle branch block and 1:1 atrioventricular conduction at or slower than 80 beats/min. Electrophysiologic study revealed transient HV interval block followed by recovery from the block at shorter coupling intervals without prolongation of the H1H2 and H2V2 intervals, suggesting true supernormal conduction. Isoproterenol enhanced the supernormal conduction, with shortening of blocked intervals and recovery of atrioventricular conduction, while atropine caused their less marked enhancement. Linking (ie, retrograde concealment of the impulse to the distal His bundle region through the blocked right bundle branch) is considered a possible mechanism of supernormal conduction in this case.
一名52岁女性表现为莫氏Ⅱ型房室传导阻滞合并右束支传导阻滞，且房室传导比例为1:1，心率80次/分钟或更低。电生理研究显示存在短暂的希氏束-心室（HV）间期阻滞，随后在较短的配对间期时阻滞恢复，且H1H2和H2V2间期未延长，提示真正的超常传导。异丙肾上腺素增强了超常传导，使阻滞间期缩短且房室传导恢复，而阿托品对其增强作用不明显。在这种情况下，折返（即冲动通过阻滞的右束支逆行隐匿至希氏束远端区域）被认为是超常传导的一种可能机制。
