Outcomes of Focused Double Extrastimuli Mapping and Ablation in Ventricular Tachycardia
Surachat Jaroonpipatkul1,2, Andrea N Keithler1, Thipsukhon Sathapanasiri3
1Division of Cardiovascular Medicine, University of Utah Health, Salt Lake City, Utah, USA.
Background:
Conventional substrate mapping for scar-related ventricular tachycardia (VT) often fails to fully delineate critical arrhythmogenic components. Functional mapping strategies using extrastimuli have shown promise but are limited by procedural complexity.
Methods:
In total, 57 patients undergoing VT ablation between March 2023 and October 2024 were included in the study. Patients were grouped based on whether targeted double extrastimuli mapping (focused DEMAP) was used to guide mapping and ablation. Mapping was performed using EnSite X with omnipolar technology. Clinical and procedural outcomes were compared between focused DEMAP and non-DEMAP groups with outcomes follow-up at 12 months.
Results:
Focused DEMAP revealed a significantly higher correlation between DZs and VT critical isthmuses compared to sinus rhythm mapping (75.9% vs. 37.1%, p = 0.01). VT-free survival at 12 months was higher in the DEMAP group (88.03%) than in the non-DEMAP group (58.10%, p = 0.04). Trends also favored DEMAP in reducing cardiovascular hospitalization (10.55% vs. 24.70%) and mortality, though not statistically significant. Overall procedure time was similar mainly driven by less time during ablation and a lower mean ablated area in the focused DEMAP group compared to the non-DEMAP group.
Conclusion:
The focused DEMAP, a focused double extrastimulus mapping strategy, enhances VT substrate identification and is associated with improved VT-free survival without prolonging procedure time. This approach may refine substrate-based ablation and optimize lesion targeting without increasing procedural burden.
