Arrhythmias & electrophysiologyResearch article
Functional Conduction Block During Extrastimulus Mapping Masks Deceleration Zones and Reveals Additional VT Substrate
- study
Authors' conclusion
Extrastimulus pacing may change the location of DZs identified on isochronal late activation mapping maps and can reveal additional substrate; functional block can mask DZs on S2 maps. Analysis of both S1 and S2 maps facilitates more comprehensive substrate characterization, and regions demonstrating significant ΔS1S2 may represent important ablation targets.
Study context
- Population
- Patients undergoing right ventricular pacing with steady-state (S1) and single extrastimulus (S2) isochronal late activation mapping for ventricular tachycardia substratepatients (age 66 ± 10 years, 9 male)
- Participants
- Eleven patients
- Comparison
- differences in ventricular tachycardia substrate identification between steady-state (S1) and single extrastimulus (S2) pacing using isochronal late activation mapping deceleration zones (DZs)
Main finding
As reported in the abstract
DZ location
- DZ location was significantly different between S1 and S2 maps
Further findings
DZs revealed or masked by extrastimulus pacing
- DZs revealed by extrastimulus pacing not identified during steady-state pacing
- 5
- DZs masked by functional conduction block on S2 maps that were present on corresponding S1 map
- 4
Colocalization of significant ΔS1S2 to the primary DZ
- maps with regions of significant ΔS1S2 colocalized to the primary DZ
- 19 of 22
- no significant difference between the proportion of positive and negative delta observed
- P = 0.898
Original publication
Functional Conduction Block During Extrastimulus Mapping Masks Deceleration Zones and Reveals Additional VT Substrate. JACC Clin Electrophysiol. Published 2 April 2026. doi:10.1016/j.jacep.2026.01.038
Summarised from the published abstract; every number is checked against it