Retrospective Window of Interest Annotation Provides New Insights Into Functional Channels in Ventricular Tachycardia...

Area of Science:

• Cardiology
• Electrophysiology
• Medical Imaging

Background:

• Accurate local activation time annotation is vital for assessing ventricular tachycardia (VT) substrate.
• Standard prospective windows of interest (sWOI) in mapping systems exclude very late potentials (LPs).

Purpose of the Study:

• To investigate the utility of a novel retrospective window of interest (rWOI) for VT substrate mapping.
• To enable accurate visualization and annotation of all LPs during VT substrate mapping.

Main Methods:

• Utilized a novel rWOI for manual annotation of latest activation in high-density VT substrate maps.
• Correlated reannotated maps to critical sites, examining areas of late activation and propagation patterns.
• Included patients with defined isthmuses and high-density VT substrate maps.

Main Results:

• The novel rWOI enabled annotation of LPs beyond the sWOI limit in 65% of cases.
• Identified two VT channel activation patterns: functional block (76%) and wave front collision (24%).
• The zone of early and late crowding marker showed higher predictive value (85%) than deceleration zones (69%) for re-entry sites.

Conclusions:

• The arbitrary limitation of sWOI in current mapping systems excludes crucial LPs.
• Future electroanatomical mapping systems require longer WOIs for precise local activation time annotation.
• The rWOI enhances the functional assessment of VT substrate by including LPs.