Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
J Cardiovasc Electrophysiol. 2021 Feb;32(2):297-304. doi: 10.1111/jce.14850. Epub 2020 Dec 29.
The right atrial posterior wall (RAPW) is known to form a conduction barrier during typical atrial flutter (AFL). We evaluated the transverse conduction properties of RAPW in patients with and without typical AFL using an ultrahigh resolution electroanatomical mapping system.
This study included 41 patients who underwent catheter ablation of AF, typical or atypical AFL, in whom we performed RAPW mapping with an ultrahigh resolution mapping system during typical AFL and coronary sinus ostial pacing with three different pacing cycle lengths (PCLs) (1) PCL1: PCL within 40 ms of the AFL cycle length in patients with typical AFL or 250-300 ms for those without, (2) PCL2: 400 ms, (3) PCL3: PCL just faster than the sinus rate. Local RAPW conduction block was evaluated by propagation mapping and local double potentials separated by an isoelectric line. The functional block was defined as areas blocked during shorter PCLs but conductive during longer PCLs. The degree of blockade was calculated by dividing the blocked length by RAPW length (%blockade). Only two patients demonstrated a fixed complete RAPW block (100%, %blockade). Thirty-one patients demonstrated a partial block of RAPW, and the %blockade during PCL1-3 was 49.4 ± 19.8%, 39.5 ± 19.2%, and 35.0 ± 22.9% in this group, respectively. Functional block areas were frequently observed above the fixed block area adjacent to the RA-inferior vena cava junction. Transverse conduction block was more frequently observed in patients with typical AFL at any longitudinal level of RAPW.
RAPW transverse conduction block is lower-side dominant and greater in patients with typical AFL than those without.
已知右房后壁（RAPW）在典型的房扑（AFL）期间形成传导阻滞。我们使用超高分辨率电解剖标测系统评估了有和无典型 AFL 的患者的 RAPW 横向传导特性。
本研究纳入了 41 例行房颤、典型或非典型 AFL 导管消融的患者，我们在典型 AFL 期间使用超高分辨率标测系统对 RAPW 进行标测，并在冠状窦口起搏时采用三种不同的起搏周期长度（PCL）：（1）PCL1：典型 AFL 患者的 AFL 周期长度内的 PCL40ms 或无典型 AFL 的患者的 250-300ms，（2）PCL2：400ms，（3）PCL3：快于窦性心率的 PCL。通过传播标测和局部双电位来评估局部 RAPW 传导阻滞。功能阻滞定义为在较短的 PCL 期间被阻滞但在较长的 PCL 期间可传导的区域。通过将阻滞长度除以 RAPW 长度来计算阻滞程度（%阻滞）。只有两名患者表现出固定的完全 RAPW 阻滞（100%，%阻滞）。31 名患者表现出 RAPW 的部分阻滞，在 PCL1-3 期间的%阻滞分别为 49.4±19.8%、39.5±19.2%和 35.0±22.9%。功能阻滞区常在上部毗邻 RA-下腔静脉交界处的固定阻滞区附近观察到。在任何 RAPW 的纵向水平，典型 AFL 患者的横向传导阻滞更常见。
RAPW 的横向传导阻滞在有典型 AFL 的患者中比无典型 AFL 的患者更常见且呈下侧优势。
