Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington.
Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Pacing Clin Electrophysiol. 2020 Nov;43(11):1273-1280. doi: 10.1111/pace.14068. Epub 2020 Sep 26.
Atypical atrial flutter (AFL) is common in patients with postsurgical atrial scar, with macro- or microscopic channels in the scar acting as substrate for reentry. Heterogeneous atrial scarring can cause varying flutter circuits, which makes mapping and ablation challenging, and recurrences common.
We hypothesize that dynamically adjusting voltage thresholds can identify heterogeneous atrial scarring, which can then be effectively homogenized to eliminate atypical AFLs.
We studied consecutive patients who presented to Electrophysiology laboratory for atypical AFL ablation with history of atriotomy and included the patients with multiple, varying flutter circuits during mapping in our study. We excluded patients with stable flutter circuit that was sustained and could be localized using traditional entrainment and activation mapping strategy. In the included patients, we performed detailed high-density voltage map of the atrium of interest. We adjusted voltage thresholds as needed to identify heterogeneity and channels in the scarred regions. A thorough scar homogenization was performed with irrigated smart-touch ablation catheter. Re-inducibility of tachycardia, and immediate and long-term outcomes were studied.
Of five studied cases, one was female; age 66 ± 10 years. All five had prior surgical substrate. All the patients had multiple flutter morphologies, which varied as we mapped the AFL. After scar homogenization, tachycardia was not inducible in any patient. No recurrence of flutter was noted during a mean follow-up duration of 450 ± 27 days.
High-density voltage mapping and homogenization of the scar can be an effective strategy in eliminating complex scar-mediated atypical AFL with multiple circuits.
手术后的心房瘢痕会导致非典型房扑（AFL），瘢痕中的宏观或微观通道可作为折返的基质。心房瘢痕的异质性会导致不同的扑动环路，这使得标测和消融具有挑战性，且容易复发。
我们假设动态调整电压阈值可以识别异质性的心房瘢痕，然后可以有效地使瘢痕均质化以消除非典型 AFL。
我们研究了连续就诊于心内科的因非典型 AFL 消融而进行电生理检查的患者，这些患者有开胸手术史，并包括在标测过程中出现多个不同的扑动环路的患者。我们排除了那些具有稳定的扑动环路的患者，这些稳定的扑动环路可以使用传统的拖带和激活标测策略来定位。在纳入的患者中，我们对感兴趣的心房进行了详细的高密度电压图。我们根据需要调整电压阈值以识别瘢痕区域的异质性和通道。使用灌流智能触摸消融导管进行彻底的瘢痕均质化。研究了心动过速的可诱发性、即刻和长期结果。
在五个研究病例中，有 1 例为女性，年龄 66 ± 10 岁。所有五个患者都有手术前的病变基质。所有患者都有多种扑动形态，随着我们对 AFL 的标测，这些形态会发生变化。在瘢痕均质化后，没有患者的心动过速可被诱发。在平均 450 ± 27 天的随访期间，没有患者出现 AFL 复发。
高密度电压图和瘢痕均质化可以是消除具有多个环路的复杂瘢痕介导的非典型 AFL 的有效策略。
