Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Japan.
J Cardiovasc Electrophysiol. 2023 Aug;34(8):1658-1664. doi: 10.1111/jce.15993. Epub 2023 Jul 2.
Although atrial flutter (AFL) is a common arrhythmia that is based on a macro-reentrant tachycardia around the tricuspid annulus, the factors giving rise to typical AFL (t-AFL) versus reverse typical AFL (rt-AFL) are unknown. To investigate the difference between t-AFL and rt-AFL circuits using ultrahigh resolution mapping of the right atrium.
We investigated 30 isthmus-dependent AFL patients (mean age 71, 28 male) who underwent first-time cavo-tricuspid isthmus (CTI) ablation guided by Boston Scientific's Rhythmia mapping system and divided them into two groups: t-AFL (22 patients) and rt-AFL (8 patients). We compared the anatomy and electrophysiology of their reentrant circuits.
Baseline patient characteristics, use of antiarrhythmic drugs, prevalence of atrial fibrillation, AFL cycle length (227.1 ± 21.4 vs. 245.5 ± 36.0 ms, p = .10), and CTI length (31.9 ± 8.3 vs. 31.1 ± 5.2 mm, p = .80) did not differ between the two groups. Functional block was observed at the crista terminalis in 16 patients and at the sinus venosus in 11. No functional block was observed in three patients, all of whom belonged to the rt-AFL group. That is, functional block was observed in 100% of the t-AFL group as opposed to 5/8 (62.5%) of the rt-AFL (p < .05). Slow conduction zones were frequently observed at the intra-atrial septum in the t-AFL group and at the CTI in the rt-AFL group.
Mapping with ultrahigh-resolution mapping showed differences between t-AFL and rt-AFL in conduction properties in the right atrium and around the tricuspid valve, which suggested directional mechanisms.
尽管心房扑动（AFL）是一种常见的基于三尖瓣环周围的宏观折返性心动过速的心律失常，但导致典型心房扑动（t-AFL）与反向典型心房扑动（rt-AFL）的因素尚不清楚。本研究旨在使用超高分辨率右心房标测来研究 t-AFL 与 rt-AFL 环之间的差异。
我们研究了 30 例首次接受波士顿科学公司的 Rhythmia 标测系统引导的腔静脉-三尖瓣峡部（CTI）消融的依赖峡部的 AFL 患者（平均年龄 71 岁，28 例男性），并将其分为两组：t-AFL（22 例）和 rt-AFL（8 例）。我们比较了它们折返环的解剖和电生理特征。
两组患者的基线特征、抗心律失常药物的使用、房颤的发生率、AFL 周期长度（227.1±21.4 vs. 245.5±36.0 ms，p=0.10）和 CTI 长度（31.9±8.3 vs. 31.1±5.2 mm，p=0.80）均无差异。16 例患者在冠状窦终末嵴处观察到功能性阻滞，11 例患者在窦房结处观察到功能性阻滞。3 例患者未观察到功能性阻滞，他们均属于 rt-AFL 组。即 t-AFL 组功能性阻滞发生率为 100%，而 rt-AFL 组为 8/8（62.5%）（p<0.05）。t-AFL 组在房间隔内和 rt-AFL 组在 CTI 处常观察到慢传导区。
超高分辨率标测显示，t-AFL 和 rt-AFL 之间在右心房和三尖瓣周围的传导特性存在差异，这表明存在方向性机制。
