Repolarization and Activation Mapping in Ventricular Tachycardia Ablation: The REDEEM Study
Luigi Pannone1, Antonio Bisignani2, Pietro Rossi3
1Heart Rhythm Management Centre, Universitair Ziekenhuis Brussel, Heart Rhythm Research Brussels, Postgraduate Program in Cardiac Electrophysiology and Pacing, Vrije Universiteit Brussel, European Reference Networks Guard-Heart, Brussels, Belgium.
Background:
Several sinus rhythm substrate mapping strategies have been described for ventricular tachycardia (VT) ablation.
Objectives:
The aim of this study was to evaluate a novel sinus rhythm mapping method for identifying critical isthmus sites based on both repolarization and activation mapping (repolarization depolarization mapping [REDEEM]).
Methods:
Patients undergoing VT ablation at 2 centers were retrospectively analyzed. The local activation time (LAT) map was performed with the LAT set to the last deflection (LATlatest) method. Each LAT map was divided into 8 isochrones. Deceleration zones (DZs) were defined as >3 isochrones within 10 mm. Unipolar repolarization mapping was performed by using the Wyatt method. A steep repolarization heterogeneity was defined as a "repolarization cliff" if 2 contiguous areas within 1 cm distance showed a difference in repolarization time >100 milliseconds.
Results:
A total of 20 patients with 20 mapped VTs were included. The VT exit site or any boundary of the diastolic channel overlapped with a repolarization cliff in 20 VTs (100.0%) and with a DZ in 14 VTs (70.0%). The VT entrance site was found to overlap with a repolarization cliff in 2 VTs (10.0%) and with a DZ in 18 VTs (90.0%). The mid-isthmus was found in an area connecting a DZ with a repolarization cliff in 19 VTs (95.0%). The positive predictive value of a repolarization cliff for any isthmus site was 63.2%, and the positive predictive value of a DZ for any isthmus site was 40.1%.
Conclusions:
The REDEEM method is feasible and shows anatomical associations with VT isthmus sites. This hypothesis-generating study provides mechanistic insights that warrant prospective validation.
