Complex atrial tachycardia with alternating cycle length:What is the mechanism?  

作　　者：FU Zu-yi TANG Li-hong ZHAN Xian-zhang LI Kang FANG Xian-hong LIAO Hong-tao DENG Hai LIU Yang WU Shu-lin XUE Yu-mei 符祖宜;唐立鸿;詹贤章;李康;方咸宏;廖洪涛;邓海;刘洋;吴书林;薛玉梅(Department of Cardiology,Guangdong Provincial Cardiovascular Institute,Guangdong General Hospital,Guangdong Academy of Medical Sciences,Guangzhou 510180,Guangdong,China;Department of Cardiology,Peking University First Hospital,Beijing 100034,China)

机构地区：[1]Department of Cardiology,Guangdong Provincial Cardiovascular Institute,Guangdong General Hospital,Guangdong Academy of Medical Sciences,Guangzhou 510180,Guangdong,China [2]Department of Cardiology,Peking University First Hospital,Beijing 100034,China

出　　处：《South China Journal of Cardiology》2020年第2期77-85,97,共10页岭南心血管病杂志（英文版）

基　　金：supported by the Key Research and Development Projects of Guangdong Province(No. 2019B020230004);the National Key Research and Development Projects (No. 2018YFC1312501/2018YFC1312502);the National Natural Science Foundation (No. 81870254)

摘　　要：Background Atrial tachycardia(AT)with cycle length(CL)alternans is uncommon and conventional mapping of this AT remains challenging. We used an ultrahigh density mapping system to rapidly map complicated circuits with sufficient spatial resolution and electrogram quality to elucidate the precise mechanism of this special ATs. Methods Of 210 consecutive patients with clinical ATs who underwent catheter ablation with the ultrahigh density mapping system,4 patients(1.9%)with CL alternans were identified. The AT alternating cycles mapped by the Rhythmia mapping system for long CL were 317±51(range 245-355)ms and for short CL were 282±51(range 235-333)ms. Both long and short cycles followed in 1∶1 sequence in all 4 patients(longshort-long-short). Results By comparing the separate maps with long and short CL,we classified ATs with CL alternans into 2 types. In type 1,CL alternans resulted from an intermittent 2∶1 conduction block through the slow conduction channel in the small circuit. In type 2,CL alternans caused by the alternated conduction velocity passing through the conduction gap were manifested. Ablation at the fractionated potentials contributes to the termination of AT in 3 of the 4 patients. Conclusions Ultrahigh density mapping system can accurately identify the mechanism of complex ATs with alternating CL. The CL alternans may be related to the intermittent conduction block within the channel of the small circuitor different conduction velocity through the identical channel. Fractionated electrogram recorded in the common isthmus or some"conduction gaps"may be a reasonable approach to terminate these ATs.

关 键 词：atrial tachycardia cycle length alternans ultrahigh density mapping 

分 类 号：R541.7[医药卫生—心血管疾病]