Yorgun Hikmet, Çöteli Cem, Kılıç Gül Sinem, Zekeriyeyev Samuray, Dural Muhammet, Aytemir Kudret
Department of Cardiology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, Maastricht, The Netherlands.
J Innov Card Rhythm Manag. 2025 Jul 15;16(7):6374-6384. doi: 10.19102/icrm.2025.16073. eCollection 2025 Jul.
Right atrial tachycardia (AT) is a frequent rhythm disorder in patients with atrial scar mainly due to surgical incisions or congenital heart diseases. Despite the mounting evidence about AT mechanisms and types, data are scarce regarding the conduction properties as well as the functional characteristics of the atrial substrate during sinus rhythm, which plays a role in the maintenance of tachycardia. We sought to evaluate the relationship between the functional substrate mapping (FSM) characteristics of the right atrium (RA) and the critical isthmus (CI) of re-entrant ATs in patients with underlying atrial scar. Patients with a history of right AT who underwent catheter ablation with three-dimensional mapping were retrospectively enrolled. A voltage map and isochronal late activation map were created during the sinus/paced rhythm using multielectrode catheters to detect deceleration zones (DZs). Subsequently, AT was induced with programmed stimulation, and activation mapping was performed to detect the CI of the tachycardia. Atrial tachyarrhythmia (ATa) recurrence was defined as the detection of atrial fibrillation or AT (≥30 s) during follow-up. A total of 24 patients (mean age, 46 ± 15 years; 13 [54%] women) with right AT were included. A total of 36 ATs were mapped (16 [44.4%] localized re-entry, 20 [55.6%] macro-re-entry). Atrial low-voltage zones composed 23.3% ± 13.0% of the total RA. The mean values of bipolar voltage, electrogram duration, and conduction velocity during sinus rhythm corresponding to the CI of ATs were 0.18 ± 0.10 mV, 121.7 ± 29.4 ms, and 0.06 ± 0.04 m/s, respectively. The total number of DZs per chamber was 1.1 ± 0.3, with all being located in the low-voltage zone (<0.5 mV) detected by high-density mapping. All CIs of non-cavotricuspid isthmus (CTI)-dependent re-entry were co-localized with DZs detected during FSM. The positive predictive value of DZs to detect the CI of inducible ATs was 80.8%. During a mean follow-up of 11.7 ± 8.1 months, freedom from atrial tachyarrhythmias was 87.5%. Although CTI-dependent macro-re-entry is the most common mechanism in patients with RA scar, our findings demonstrated the relevance of FSM to predict non-CTI-dependent ATs. Conduction slowing manifested as DZs with continuous-fragmented signal morphology may guide ablation strategy tailoring in the case of underlying RA scar.
右房性心动过速（AT）是心房瘢痕患者中常见的心律失常，主要由手术切口或先天性心脏病引起。尽管关于AT机制和类型的证据越来越多，但关于窦性心律时心房基质的传导特性和功能特征的数据却很稀少，而这些特性在心动过速的维持中起作用。我们试图评估右心房（RA）的功能基质标测（FSM）特征与潜在心房瘢痕患者折返性AT的关键峡部（CI）之间的关系。回顾性纳入有右房性心动过速病史并接受三维标测导管消融的患者。在窦性/起搏心律期间，使用多电极导管创建电压图和等时性晚期激动图，以检测减速区（DZs）。随后，通过程序刺激诱发AT，并进行激动标测以检测心动过速的CI。房性快速心律失常（ATa）复发定义为随访期间检测到房颤或AT（≥30秒）。共纳入24例右房性心动过速患者（平均年龄46±15岁；13例[54%]为女性）。共标测了36次AT（16次[44.4%]为局灶性折返，20次[55.6%]为大折返）。心房低电压区占RA总面积的23.3%±13.0%。与AT的CI相对应的窦性心律期间双极电压、电图持续时间和传导速度的平均值分别为0.18±0.10 mV、121.7±29.4 ms和0.06±0.04 m/s。每个腔室的DZ总数为1.1±0.3，均位于高密度标测检测到的低电压区（<0.5 mV）。所有非腔静脉三尖瓣峡部（CTI）依赖性折返的CI均与FSM期间检测到的DZ共定位。DZ检测可诱导AT的CI的阳性预测值为80.8%。在平均11.7±8.1个月的随访期间，房性快速心律失常的无发作率为87.5%。尽管CTI依赖性大折返是RA瘢痕患者中最常见的机制，但我们的研究结果表明FSM对预测非CTI依赖性AT具有相关性。传导减慢表现为具有连续碎裂信号形态的DZ，可能指导潜在RA瘢痕情况下的消融策略制定。
