P382Bipolar electrograms directed across wavefronts provide greater physiological accuracy
Notice bibliographique
Résumé
Background: The orientation of a bipole along or across the wavefront direction influences electrogram (EGM) appearance, thus providing ambiguous measurements both in terms of timing and frequency content that have no reliable physiological interpretation. Bipolar measurements of activation timing have been challenged. EGM measurements not influenced by wavefront direction with Omnipolar Mapping Technology (OT) could increase signal fidelity and improve discrimination timing. Objectives: We sought to: 1) Characterize the frequency content and the width of timing information contained in regular bipolar and OT EGM signals and assess whether the OT-EGMs provide more physiological information than bipolar EGMs. 2) Document how these EGMs are distinctive visually by electrophysiologists in terms of near-field and non-near field classification. Methods: A high-density custom-made electrode array (1mm electrodes, 2x2mm spacing) was deployed in 2 pig Langendorff perfused healthy ventricles with certainty of tissue contact. One hundred bipolar EGMs were collected labeled horizontal (H, n=50) and vertical (V, n=50). One hundred more perpendicular but direction-independent EGMs were computed from these same bipoles with OT in directions denoted as OT-Ea (n=50 along the travelling wave’s activation direction) and OT-Ew (perpendicular to OT-Ea, n=50). All EGMs were randomized and blindly analyzed with same scaling and filtering by 8 experienced electrophysiologists that had to discriminate them as near-field signal or non-near-field. Frequency content of the EGMs was automatically analyzed with fast Fourier transform (FFT) of the signal. Width of the absolute dV/dt of the EGMs was analyzed with custom-made MATLAB code. Results: Overall, EGMs recorded were classified as near field by electrophysiolgists 44.5% of the times. Bipolar H and V EGMs were interpreted as near field in 46.3% of recordings. Of the OT directed EGMs, OT-Ea recordings were interpreted as near field in 46.0% of cases (p=0.6 vs H and V bipoles). OT-Ew EGMs were distinctive, interpreted as near-field in 36.0% of cases, p<0.05 vs other recordings. In addition, the frequency content of OT-Ew was higher than for common bipoles and OT-Ea (69.9±21Hz vs 60.9±14Hz vs 52.0±6.7Hz respectively, p<0.001), indicating a sharper morphology of the signal. In addition, the average width of the dV/dt of the EGMs was smaller for OT-Ew compared to bipoles and to OT-Ea respectively (10.3±4ms vs 13.4±3.3ms vs 15.8±2.1ms, p<0.05) indicating less possible error of annotation if used as a timing tag. Conclusions: Despite obtaining EGMs in good contact with the tissue, visual assessment often misclassifies bipolar EGMs as non-near field depending on their position along or across the wavefront. The frequency content and the width of dV/dt of the EGMs obtained across a wavefront (OT-Ew) indicate a sharper and narrower signal, which could be used to improve physiological reliability of timing of local annotation.
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Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,004 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».