Method to predict isthmus location in ventricular tachycardia caused by reentry with a double-loop pattern

Area of Science:

• Cardiovascular Electrophysiology
• Computational Biology
• Medical Imaging

Background:

• Inducing and mapping reentrant ventricular tachycardia during electrophysiologic studies can be challenging.
• Sinus-rhythm electrogram analysis offers a potential method for reentry localization.
• A novel technique for analyzing sinus-rhythm electrogram shape is presented, avoiding arbitrary thresholds.

Purpose of the Study:

• To describe a method for localizing double-loop reentrant circuits driving clinical tachycardias using sinus-rhythm electrogram analysis.
• To validate the accuracy of this method in predicting the tachycardia isthmus.

Main Methods:

• Reentrant ventricular tachycardia was induced in canine hearts post-myocardial infarction.
• Sinus-rhythm activation maps were created using bipolar electrograms from the epicardial border zone.
• Mean peak deflection (MPD) and deviation (DPD) of electrograms were analyzed to estimate activation wavefront crossing and local electrical activity duration.

Main Results:

• A line of uniform and sharp MPD gradient accurately predicted the propagation direction through the reentrant circuit isthmus.
• Sharp DPD transitions identified arcs of block bordering the isthmus during tachycardia.
• The method achieved an 84.1% overlap in predicting the actual tachycardia isthmus.

Conclusions:

• Sinus-rhythm electrogram analysis can effectively localize the reentrant ventricular tachycardia isthmus.
• This approach eliminates the need for arbitrary threshold points and peak selections, reducing potential errors.