Institute for Cardiovascular Science, University College London, 5 University Street, London WC1E 6JF, UK.
Barts Heart Centre, St Bartholomew's Hospital, W Smithfield, London EC1A 7BE, UK.
Europace. 2024 Nov 1;26(11). doi: 10.1093/europace/euae271.
Alterations in repolarization gradients and increased heterogeneity are key electrophysiological determinants of ventricular arrhythmogenesis across a variety of aetiologies with and without structural heart disease. High-density repolarization mapping to localize these repolarization abnormalities could improve characterization of the individual arrhythmogenic substrate and inform more targeted ablation. Yet, due to challenges posed by intrinsic features of human cardiac repolarization itself as well as technical and practical limitations, they are not routinely assessed, and traditional substrate mapping techniques remain strictly limited to determining conduction abnormalities. Here, we provide an overview of the mechanistic role of repolarization alterations in ventricular re-entry arrhythmias followed by a description of a clinical workflow that enables high-density repolarization mapping during ventricular tachycardia (VT) ablations using existing clinical tools. We describe step-by-step guidance of how-to set-up and generate repolarization maps illustrating the approach in case examples of structural normal and abnormal hearts. Furthermore, we discuss how repolarization mapping could be combined with existing substrate mapping approaches, including isochronal late activation mapping, to delineate sites of increased re-entry vulnerability, that may represent targets for ablation without the requirement for VT induction. Finally, we review challenges and pitfalls and ongoing controversies in relation to repolarization mapping and discuss the need for future technical and analytical improvements in repolarization mapping to integrate into ventricular substrate mapping strategies. Repolarization mapping remains investigational, and future research efforts need to be focused on prospective trials to establish the additional diagnostic value and its role in clinical ablation procedures.
复极梯度的改变和异质性的增加是各种有或无结构性心脏病病因导致室性心律失常发生的关键电生理决定因素。高密度复极标测来定位这些复极异常可以改善个体心律失常基质的特征，并提供更有针对性的消融。然而，由于人类心脏复极本身的固有特征以及技术和实际限制带来的挑战，这些异常并没有被常规评估，传统的基质标测技术仍然严格局限于确定传导异常。在这里，我们首先概述了复极改变在室性折返性心律失常中的机制作用，然后描述了一种临床工作流程，该流程使用现有的临床工具在室性心动过速（VT）消融期间实现高密度复极标测。我们描述了如何设置和生成复极图的分步指导，通过结构性正常和异常心脏的病例示例来说明该方法。此外，我们讨论了如何将复极标测与现有的基质标测方法（包括等时晚期激活标测）相结合，以描绘折返易损性增加的部位，这些部位可能代表消融的靶点，而无需进行 VT 诱发。最后，我们回顾了与复极标测相关的挑战和争议，并讨论了未来在复极标测方面需要进行技术和分析改进，以整合到心室基质标测策略中。复极标测仍处于研究阶段，未来的研究工作需要集中在前瞻性试验上，以确定其附加诊断价值及其在临床消融程序中的作用。
