Sau Arunashis, Sikkel Markus B, Luther Vishal, Wright Ian, Guerrero Fernando, Koa-Wing Michael, Lefroy David, Linton Nicholas, Qureshi Norman, Whinnett Zachary, Lim Phang Boon, Kanagaratnam Prapa, Peters Nicholas S, Davies D Wyn
Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.
Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK.
J Cardiovasc Electrophysiol. 2017 Dec;28(12):1445-1453. doi: 10.1111/jce.13323. Epub 2017 Sep 14.
We hypothesized that very high-density mapping of typical atrial flutter (AFL) would facilitate a more complete understanding of its circuit. Such very high-density mapping was performed with the Rhythmia (Boston Scientific) mapping system using its 64 electrode basket catheter.
Data were acquired from 13 patients in AFL. Functional anatomy of the right atrium (RA) was readily identified during mapping including the Crista Terminalis and Eustachian ridge. The leading edge of the activation wavefront was identified without interruption and its conduction velocity (CV) was calculated. CV was not different at the cavotricuspid isthmus (CTI) compared to the remainder of the RA (1.02 vs. 1.03 m/s, P = 0.93). The sawtooth pattern of the surface electrocardiogram (EKG) flutter waves was compared to the position of the dominant wavefront. The downslope of the surface EKG flutter waves represented on average 73% ± 9% of the total flutter cycle length. During the downslope, the activation wavefront traveled significantly further than during the upslope (182 ± 21 milliseconds vs. 68 ± 29 milliseconds, P < 0.0001) with no change in CV between the two phases (0.88 vs. 0.91 m/s, P = 0.79).
CV at the CTI is not slower than other RA regions during typical AFL. The gradual downslope of the sawtooth EKG is not due to slow conduction at the CTI suggesting that success of ablation at this site relates to anatomical properties rather than the presence of a "slow isthmus."
我们假设对典型心房扑动（AFL）进行超高密度标测将有助于更全面地了解其折返环。使用波士顿科学公司的Rhythmia标测系统及其64极篮状导管进行了这种超高密度标测。
从13例AFL患者获取数据。在标测过程中很容易识别出右心房（RA）的功能解剖结构，包括界嵴和欧氏嵴。激活波前的前缘被连续识别并计算其传导速度（CV）。与RA的其余部分相比，三尖瓣峡部（CTI）的CV无差异（1.02对1.03 m/s，P = 0.93）。将体表心电图（EKG）扑动波的锯齿样形态与主导波前的位置进行比较。体表EKG扑动波的下降支平均占整个扑动周期长度的73%±9%。在下降支期间，激活波前传播的距离明显长于上升支（182±21毫秒对68±29毫秒，P < 0.0001），且两个阶段之间的CV无变化（0.88对0.91 m/s，P = 0.79）。
在典型AFL期间，CTI处的CV并不比RA的其他区域慢。锯齿样EKG的逐渐下降支并非由于CTI处传导缓慢，这表明该部位消融成功与解剖学特性有关，而非存在“缓慢峡部”。
