Temporal and spatial pacemap parameters for identification of cardiac surfaces with critical sites for ventricular tachycardia

Abstract

Introduction Multisurface pacemapping may help identify the surface of interest in scar‐related ventricular tachycardia (VT). This study aimed to investigate the performance of pacemap parameters for detecting critical sites through multisurface mapping. Methods and Results In 26 patients who underwent scar‐related VT ablation, pacemap parameters including a matching score, the difference between the longest and shortest stimulus‐QRS intervals (Δs‐QRS), and the distance between the good pacemap sites were measured. The parameters were compared between surfaces with and without critical sites and ablation outcomes. A total of 941 pacemap at 56 surfaces targeting 35 VTs were analyzed. A greater Δs‐QRS (40 vs. 8 ms, p < .001) and longer distance between two good pacemap sites (24 vs. 13 mm, p < .001) were observed on the surfaces with critical sites. A similar trend was seen in multisurface pacemapping for the same VTs (52 vs. 18 ms in Δs‐QRS, p = .021; 37 vs. 12 mm in distance, p = .019), although the best pacemap scores were comparable (94 vs. 87, p = .295). The Δs‐QRS > 20 ms and the distance >19 mm showed high positive likelihood ratios (19.8 and 6.1, respectively) for discriminating the surface harboring the critical site. Ablation of VTs fulfilling these parameters was successful on the surfaces, but without the required multisurface ablation. Conclusion Temporal (Δs‐QRS) and spatial (distance) parameters for good pacemap match sites were excellent markers for detecting the surface harboring critical sites in scar‐related VT. A multisurface pacemapping can successfully identify the surface of interest.

Correlation of spatial patterns of endocardial pace mapping to underlying scar topography in patients with scar‐related ventricular tachycardia

“…or epicardial). [4][5][6] This study adds new insights to previous PM studies and extends the understanding of endocardial PM correlations in SHD patients. The main findings of this study are as follows:…”

“…To date, there has been no systematic study of the relationship between the spatial pattern of endocardial PM in SHD‐related VT and underlying scar topography. A significant amount of recent work has highlighted that the temporal and spatial pattern of PMs may allow the localization of the surface of VT isthmii (endo, mid, or epicardial) 4–6 . This study adds new insights to previous PM studies and extends the understanding of endocardial PM correlations in SHD patients.…”

“…This is explained by recent data from high‐density endo‐epicardial multielectrode mapping studies that demonstrated the three‐dimensional (3D) construct of the VT circuits which is fundamentally predicated by complex scar topography 3 . Expanding on this work, recent reports show temporal and spatial patterns seen in PM correlation maps may identify the surface location of VT isthmii (endocardial or epicardial) 4–6 . However, the relationship of PM patterns to underlying scar topography is unknown.…”

“…3 Expanding on this work, recent reports show temporal and spatial patterns seen in PM correlation maps may identify the surface location of VT isthmii (endocardial or epicardial). [4][5][6] However, the relationship of PM patterns to underlying scar topography is unknown.…”