Understanding repolarization in the intracardiac unipolar electrogram: A long-lasting controversy revisited

• DOI: 10.3389/fphys.2023.1158003
• Publication Date: 2023-04-07T04:22:13Z
• Authors: Job Stoks; Laura R. Bear; Johan Vijgen; Paul Dendale; Ralf Peeters; Paul G. A. Volders; Matthijs J. M. Cl...
• Keywords: T wave; Torso; Effective refractory period

Background: The optimal way to determine repolarization time (RT) from the intracardiac unipolar electrogram (UEG) has been a topic of debate for decades. RT is typically determined by either Wyatt method or “alternative method,” which both consider UEG T-wave slope, but differently. Objective: To measure on UEG. Methods: Seven pig hearts surrounded an epicardial sock with 100 electrodes were Langendorff-perfused selective cannulation left anterior descending (LAD) coronary artery and submersed in torso-shaped tank containing 256 torso surface. Repolarization was prolonged non-LAD-regions infusing dofetilide shortened LAD-region using pinacidil. (t ) alternative Alt methods, invasive (recorded electrodes) non-invasive UEGs (reconstructed electrocardiographic imaging). t compared local effective refractory period (ERP). Results: With contact mapping, mean absolute error (MAE) vs. ERP 21 ms 71 ms, respectively. Positive T-waves had earlier than negative T-waves, line theory. -but not -shortened infusion Similar results found (MAE 30 92 respectively). Conclusion: most accurate (non) UEGs, based novel historical analyses. Using it could unify facilitate assessment amplify its role cardiac electrophysiology.