Abstract Or302: Differentiating Local from Global Repolarization Changes During Intra-Cardiac Mapping: The Inception of a Novel Mapping Technology
Bibliographic record
Abstract
Background: Steep local repol gradients are critically more important than global repol changes. Activation recovery intervals (ARI) of unipolar electrograms (Uni) estimation of repol integrate far-field signals and may not detect local gradients. Multielectrode array catheters have allowed for the innovation of principal component-referenced Uni (Uni PCR ), which attenuates far-field contribution in electrical signals. Here we apply this concept to estimate global and local repol changes. Hypothesis: We assessed the hypothesis that Uni PCR ARI will correlate to optical APD80 better than Uni ARI and Uni PCR ARI will more accurately detect local repol changes than Uni ARI by attenuating the far-field. Aim: We aimed to validate Uni PCR as a superior alternative to the Wyatt ARI method on Uni with optical APD80 as reference in detecting local repol changes. Methods: To validate Uni PCR ARI for detecting global repol changes, we conducted simultaneous optical and electrical mapping in a rabbit model (n=3) following pinacidil/ibutilide infusion and compared optical APD to Uni vs Uni PCR ARIs. To alter repol locally, we performed epicardial mapping in pig Langendorff experiments (n=4) and topically administered lidocaine at the center of the electrode array. We compared the changes in ARI from Uni vs. Uni PCR before and after application of the drug. Results: When repol is altered globally, there is a high correlation between both Uni PCR and optical APD80 (slope = 0.98, R 2 = 0.90) and Uni and optical APD80 (slope = 0.99, R 2 = 0.91). When there is a local repol gradient, a greater difference in percent change near vs. far from the application site was observed in the Uni PCR (32.0%, p <0.0001) compared to the Uni (5.2%, p = 0.0144). Uni PCR ARI (AUC-ROC = 0.9) more accurately predicted areas near vs. far from the application site than Uni ARI (AUC-ROC = 0.7). Conclusion: Global changes in repol can be detected by both Uni and Uni PCR ARI. However, Uni PCR is more sensitive to local repol gradients than Uni ARI. Implementing such mapping technology has greater implications for defining arrhythmogenicity of regional myocardium.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".