房室折返性心动过速伴RR间期长短交替发生机制的研究

Study on the mechanism of atrioventricular reentrant tachycardia with RR interval alternation

目的探讨房室折返性心动过速(atrioventricular reciprocating tachycardia,AVRT)伴RR间期长短交替的发生机制。方法回顾性分析2009年8月至2016年8月,在泰达国际心血管病医院心内科经导管射频消融治疗的AVRT患者317例临床资料,AVRT时给予异博定5 mg,缓慢静脉推注10 min,给药后观察是否有RR间期、AH间期、HV间期和VA间期变化,以及变化发生的时间。结果给予异博定后有8例患者发生RR间期长短交替,并且均伴QRS波电交替,RR间期长短交替现象发生时均为相邻心搏的AH间期差值逐渐延长,无AH跳跃,HV间期和VA间期恒定,此现象发生于给药后6~17 min,心动过速平均周期比给药前延长16~42 ms;3例患者RR间期长短交替现象消失时均为相邻心搏的AH间期差值逐渐缩短,无AH跳跃,HV和VA间期恒定,直至AH间期相等,消失时间为给药后19~57 min;5例患者给药后AVRT终止。结论由此推断其发生机制是由于心动过速时AH间期频率依赖性递减传导所致,这一心电现象不能被程序刺激诱发。

Objective To explore the mechanism of the alternation of RR interval length in atrioventricular reentrant tachycardia(AVRT).Methods From August 2009 to August 2016,317 patients with AVRT were treated by radiofrequency catheter ablation in cardiology department of TEDA International Cardiovascular Hospital were analyzed retrospectively.During AVRT,5 mg of verapamil was given slowly intravenously for 10 min.After administration,the changes of RR interval,AH interval,HV interval and VA interval were observed and the time of changes was also observed.Results After administration of verapamil,there were 8 patients with RR interval alternation and QRS wave alternation.When RR interval alternation occurred,the difference of AH interval between adjacent heart beats was gradually extended,without AH jump,and the HV interval and VA interval were constant.This phenomenon occurred 6-17 minutes after administration,and the average cycle of tachycardia was 16-42 ms longer than before administration.In 3 patients,RR interval alternation occurred.When the phenomenon disappeared,the difference of AH interval between adjacent heart beats was gradually shortened,there was no AH jump,and the interval between HV and VA was constant until AH interval was equal,the disappearance time was 19-57 min after administration;AVRT was terminated in 5 patients after administration.Conclusion It can be concluded that the mechanism is due to the frequency dependent decreasing conduction of AH interval in tachycardia,which can not be induced by program stimulation.