Correlation between sinus rhythm deceleration zones and critical sites for localized reentrant atrial flutter: A retrospective multicenter analysis.

Background: Atypical left atrial flutter (AFL) may be macroreentrant or spatially localized. The relationship between the critical isthmus (CI) for localized reentry with sinus rhythm (SR) conduction slowing has not been systematically examined.

Objective: To examine the correlation between CI sites for localized AFL (L-AFL) and deceleration zones (DZ) identified by isochronal late activation mapping (ILAM) during baseline rhythm.

Open-window mapping of accessory pathways utilizing high-density mapping.

Purpose: Accessory pathway (AP) mapping is currently based on point-by-point mapping and identifying if a local electrogram's origin is atrial, pathway, or ventricular, which is time-consuming and prone to insufficient mapping. We sought to determine the feasibility of automated and high-density mapping to define AP location using open-window mapping (OWM), which does not rely on defining the electrogram's origin but simply detects the sharpest local signal at each point.

Methods: We enrolled 23 consecutive patients undergoing catheter ablation for atrioventricular reentrant tachycardia.