Abstract
Funding Acknowledgements
Type of funding sources: None.
Background – Wave front inhomogeneous propagation is crucial for reentry circuit generation. Bipolar EGM duration is indicative of local conduction delay and may identify areas of low conduction as a functional substrate. This study aimed to create a map of EGM duration during the VT (VEDUM Map) to identify the area of the slowest conduction and to verify if RF delivery at this area allows to rapidly interrupt the VT.
Methods – 24 high-density VTs maps (21 patients) were analyzed. Activation maps and voltage maps during SR were performed. An offline remap confirmed with MathLab software was customized to visualize the longest duration electrogram during VT.
Results – All of the VTs were interrupted during the first RF delivery (mean time 7,3 ± 5,4 sec (range 3-25 sec)) at the area with the longest EGM duration (212 ± 47 ms (range 113-330 ms)). . In 9 pts (37,5%) the longest EGM was located at the entrance or exit area of the activation maps while in 5 pts (21%) the EGM covered the full diastolic phase. Finally, in 10 pts the longest EGM occurred in the mid-exit-diastolic phase.
Conclusions - A novel Ventricular map of Electrograms DUration (VEDUM Map) is highly accurate in defining a conductive vulnerable zone of the VT circuit. The longest EGM duration within the isthmus is highly predictive of rapid VT termination. Quantitative variablesQualitative variablesMeanMedianStandard DeviationAge71738.40BMI26.624.54.02LV EDV16315442.7LV EDD61.2629.9LV EF38.7369.74VT cycle lenght (TCL)35537556.4EGM max. duration in VT21220847EGM max dur / TCL58.260.512Maximum EGM duration localization in CLProto = 12.5%Meso = 33.3%Tele = 25%Full = 20.8%Myocardium voltage characteristics in VEDUM EGMHealthy = 25%Transition = 20.8%Scar = 41.7%Critical Isthmus area12.3107.3VT Interruption during RFYes = 79.2%No = 20.8%Time (seconds) to interruption765Access typeEndo = 58.3%Epi = 29.2%Clinical and procedural dataAbstract Figure.
Slow Potential at the Entrance of the Slow Conduction Zone in the Reentry Circuit of a Verapamil‐Sensitive Atrial Tachycardia Originating From the Atrioventricular Annulus