Department of Cardiology, Cardiovascular Research Center, Buddhist Tzu Chi General Hospital and Tzu Chi University, No. 707, Section 3, Zhongyang Road, Hualien City, Taiwan.
Medicine and Institute of Clinical Medicine, National Yang-Ming Chiao-Tung University, Taipei, Taiwan.
J Interv Card Electrophysiol. 2023 Oct;66(7):1631-1639. doi: 10.1007/s10840-023-01480-5. Epub 2023 Jan 24.
Reentrant atrial tachycardias (ATs) utilize critical isthmus (CI) for the maintenance of the circuit. The electrophysiological characteristics and clinical implications of the targeted CI regions of reentrant ATs during sinus rhythm (SR) were not clear. Therefore, our research aims at studying the electrical properties of the CI sites for scar-related reentrant ATs and the functional substrate mapping identified during SR.
Patients mapped with high-density catheters during SR and reentrant ATs were retrospectively analyzed. The CI regions of the reentrant ATs were confirmed by the combination of the activation map and the entrainment. The substrate mapping was analyzed for wavefront propagation, conduction velocity, and electrogram patterns.
Twenty patients with 22 reentrant ATs that underwent high-density maps were analyzed at 2 hospitals. Mapping performed during SR identified a scar region of 23.0 ± 13.6% of the left atrium. Regions of the CI in SR were characterized by low voltage (0.3 ± 0.2 mV), conduction slowing (0.4 ± 0.2 m/s), and fractionated electrogram (duration 62.5 ± 13.9 ms). Substrate mapping during SR showed that the regions of the CI located with the low-voltage zone in 16 out of 22 CI (72.7%), the deceleration zone in 15 out of 22 CI (68.2%), and late atrial activation in 12 out of 22 CI (54.5%). Targeting regions of CI achieve 94% of termination or change of the reentrant circuit. At 6.2 ± 7.1 months, there was 75% freedom from atrial arrhythmia.
Novel high-density mapping can identify the functional substrates during SR and guide ablation. Low-voltage areas with conduction slowing are putative predictors of the CI for the maintenance of the reentrant ATs.
折返性房性心动过速（AT）利用关键峡部（CI）来维持环路。窦性节律（SR）期间折返性 AT 的靶向 CI 区域的电生理特征和临床意义尚不清楚。因此，我们的研究旨在研究与瘢痕相关的折返性 AT 的 CI 部位的电特性以及在 SR 期间确定的功能性基质标测。
对 SR 和折返性 AT 期间进行高密度导管标测的患者进行回顾性分析。折返性 AT 的 CI 区域通过激活图和拖带的结合来确认。对基质标测进行波阵面传播、传导速度和电图模式分析。
在 2 家医院对 20 名接受高密度图的 22 例折返性 AT 患者进行了分析。在 SR 期间进行的标测确定了左心房的 23.0±13.6%的瘢痕区域。SR 中的 CI 区域具有低电压（0.3±0.2 mV）、传导减慢（0.4±0.2 m/s）和碎裂电图（持续时间 62.5±13.9 ms）的特征。SR 期间的基质标测显示，在 22 个 CI 中的 16 个（72.7%）CI 区域位于低电压区域，22 个 CI 中的 15 个（68.2%）CI 区域位于减速区域，22 个 CI 中的 12 个（54.5%）CI 区域位于晚期心房激活区域。靶向 CI 区域可使 94%的折返性心动过速终止或改变折返性心动过速。在 6.2±7.1 个月时，75%的患者无房性心律失常。
新型高密度标测可在 SR 期间识别功能基质并指导消融。具有传导减慢的低电压区域是维持折返性 AT 的 CI 的推测预测因子。
