Third Heart Rhythm Congress, Birmingham, 19th-22nd October 2008
Notice bibliographique
Résumé
The pathophysiological basis of Brugada syndrome (BS) remains contentious. Characterized by a triad of right bundle branch block pattern in V1 -V3, coved ST elevation in right precordial leads, and sudden cardiac death, it remains one of the leading causes of sudden cardiac death in the young. Two principal mechanisms are thought to be responsible for BS: (i) right ventricular (RV) conduction delay and (ii) RV subepicardial action potential shortening. To date, there has been no report of in vivo high-density mapping of the Brugada heart in man. We set out to characterize the electrophysiological arrhythmogenic substrate in human RV in BS using high-density endocardial mapping. This study evaluated the conduction and repolarization properties of the RV in BS subjects. Methods and results: Thirty patients (BS n 18; controls n 12) were studied using non-contact mapping. A non-contact mapping array was deployed in the RV of BS subjects and controls. A detailed geometry of the chamber was created by a 5 kHz locator signal emitted by the drag catheter and received by two ring electrodes on the array. Right ventricular pacing was established using a pacing lead placed in the RV apex. Right ventricular pacing was established at a constant coupling interval of 600 and 400 ms. After a steady state had been reached following 3 min of pacing, an extrastimulus (S2) was introduced after a train of 10 beats. The coupling interval of S1 -S2 was decremented by 40 ms every cycle from steady state to 400 ms, by 20 ms every cycle to 300 ms and by 5 ms every cycle from 300 ms until the ventricular effective refractory period (ERP) was encountered. Conduction and restitution curves were generated from multiple sites within the RV, RV outflow tract (RVOT), and RV apex. Significant regional conduction delays in the anterolateral free wall of the RVOT of Brugada patients were identified. The mean increase in delay was 67% greater in this region compared with the body and apex (P 0.027). Local conduction velocity was also maximally reduced in this area: 0.33 + 0.02 mm/ms in BS vs. 0.52 + 0.04 mm/ms (P , 0.001) in controls. The uniformity of wavefront propagation as measured by the coefficient of linear regression r 2 was 0.94 + 0.01 for BS vs. 0.84 + 0.03 for controls (P , 0.001) (Figure The odds ratio of BS hearts having any RV segment with S max . 1 was 3.79 vs. controls (P , 0.05). Five episodes of provoked VT arose from wavebreaks originating from RVOT slow conduction zones in five separate patients. Conclusion: Marked regional endocardial conduction delay and heterogeneities in repolarization exist in BS. Wavebreak in areas of maximal conduction delay appears to be critical in the initiation and maintenance of VT with degeneration into VF in this condition. Mapping to identify and direct therapies to these RVOT sites may enable the prevention of lethal arrhythmia in BS.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
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 | 0,000 |
| 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 | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,002 |
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 ».