Cardiology Department, Lisbon Academic Medical Centre, Santa Maria University Hospital (CHULN), Lisbon, Portugal.
Cardiac Rhythm Abnormalities Unit, Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal.
J Cardiovasc Electrophysiol. 2022 Jun;33(6):1211-1222. doi: 10.1111/jce.15470. Epub 2022 Apr 7.
Automated systems for substrate mapping in the context of ventricular tachycardia (VT) ablation may annotate far-field rather than near-field signals, rendering the resulting maps hard to interpret. Additionally, quantitative assessment of local conduction velocity (LCV) remains an unmet need in clinical practice. We evaluate whether a new late potential map (LPM) algorithm can provide an automatic and reliable annotation and localized bipolar voltage measurement of ventricular electrograms (EGMs) and if LCV analysis allows recognizing intrascar conduction corridors acting as VT isthmuses.
In 16 patients referred for scar-related VT ablation, 8 VT activation maps and 29 high-resolution substrate maps from different activation wavefronts were obtained. In offline analysis, the LPM algorithm was compared to manually annotated substrate maps. Locations of the VT isthmuses were compared with the corresponding substrate maps in regard to LCV.
The LPM algorithm had an overall/local abnormal ventricular activity (LAVA) annotation accuracy of 94.5%/81.1%, which compares to 83.7%/23.9% for the previous wavefront algorithm. The resultant maps presented a spatial concordance of 88.1% in delineating regions displaying LAVA. LAVA median localized bipolar voltage was 0.22 mV, but voltage amplitude assessment had modest accuracy in distinguishing LAVA from other abnormal EGMs (area under the curve: 0.676; p < .001). LCV analysis in high-density substrate maps identified a median of two intrascar conduction corridors per patient (interquartile range: 2-3), including the one acting as VT isthmus in all cases.
The new LPM algorithm and LCV analysis may enhance substrate characterization in scar-related VT.
在室性心动过速（VT）消融的情况下，用于基质映射的自动化系统可能会注释远场而不是近场信号，从而使得到的地图难以解释。此外，局部传导速度（LCV）的定量评估在临床实践中仍然是一个未满足的需求。我们评估一种新的晚期电位图（LPM）算法是否可以提供自动和可靠的注释，并对心室电图（EGM）进行局部双极电压测量，以及 LCV 分析是否可以识别作为 VT 峡部的传导途径。
在 16 名因瘢痕相关 VT 消融而就诊的患者中，获得了 8 个 VT 激活图和 29 个来自不同激活波前的高分辨率基质图。在离线分析中，将 LPM 算法与手动注释的基质图进行比较。比较 VT 峡部的位置与相应的基质图在 LCV 方面的关系。
LPM 算法的整体/局部异常心室活动（LAVA）注释准确性分别为 94.5%/81.1%，而前一波前算法分别为 83.7%/23.9%。生成的地图在描绘显示 LAVA 的区域方面具有 88.1%的空间一致性。LAVA 的中位局部双极电压为 0.22 mV，但电压幅度评估在区分 LAVA 与其他异常 EGM 方面的准确性适中（曲线下面积：0.676；p<.001）。高密度基质图中的 LCV 分析确定了每位患者中位数为两条腔内传导途径（四分位距：2-3），包括所有情况下作为 VT 峡部的那条途径。
新的 LPM 算法和 LCV 分析可能会增强与瘢痕相关 VT 的基质特征。
