Loss of atrial pacing in a patient with a dual‐chamber permanent pacemaker: What is the mechanism?
Notice bibliographique
Résumé
A 56-year-old woman with prior history of dual-chamber permanent pacemaker (PPM) implantation (ELA Medical Symphony DR 2550, ELA Medical, Montrouge, France) for symptomatic complete heart block presented to the Cardiac Rhythm Device Clinic because of increased shortness of breath. A surface 12-lead electrocardiogram (ECG) showed no pacing activity in the atrium (Fig. 1). What is the mechanism? Twelve-lead ECG showing ventricular pacing and complete heart block. Atrial oversensing due to lead integrity failure (fracture, insulation failure) or connector problems between the header and the lead. Atrial lead displacement: no evidence of micro- or macro-displacement was found on chest radiography. Asynchronous mode of pacing (VOO) due to magnet or programming: device interrogation ruled out this differential diagnosis. The device was fully functional in DDDR mode. Battery end of life triggering VVI mode with underlying complete heart block. Differential diagnoses such as atrial oversensing and lead failures can manifest together, since lead or connector problems can cause oversensing of non-physiologic cardiac signals. In this particular case, all other possible causes were ruled out. Pacemaker interrogation was performed (Fig. 2) and showed atrial mode switch (AMS) due to atrial oversensing. Appropriate AMS refers to the ability of the pacemaker to change automatically from one mode to another in response to atrial tachyarrhythmia. The atrial lead revealed no capture at 5.0 V/1.5 ms, P-wave sensing of 0.7 mV, and an impedance level above 3000 Ω. Intracardiac electrocardiograms obtained from the pacemaker interrogation showing atrial oversensing due to atrial noise and the consequently activated mode switch. The patient had DDD pacing when we performed PM interrogation. Diagnosis obtained from the device revealed atrial arrhythmia and mode switches due to atrial tachyarrhythmia. In addition, the asynchronous pacing mode or magnet mode was adjusted to 80 ppm. However, in our patient, VP rate was 898 ms (66 ppm), and no magnet mode was noted in the device log that was consistent with the AMS rate. This pacemaker is made by Sorin (ELA Medical Symphony DR 2550, ELA Medical, Montrouge, France) and is equipped with a rate response function that is regulated by a minute ventilation sensor. In ELA devices, minute ventilation is measured by using the RA lead with an 8-Hz low-amplitude current. If the RA lead is fractured, the pacemaker automatically increases voltage to maintain the current, and the sensing of this high voltage output prompts an auto-mode switch. In fact, the regular noise in this case was 8 Hz. Therefore, we believe that this was the actual cause of the auto-mode switch. In conclusion, 12-lead ECG interpretation is important in recognizing possible PPM-related problems. All authors declare that the manuscript, as submitted or its content in another version, is not under consideration for publication elsewhere and will not be submitted elsewhere, until a final decision is made by the editors of the Journal of Arrhythmia. All authors declare no conflict of interest related to this study. All authors have made substantive contributions to the study, and all authors endorse the data and conclusions. Nevertheless, confirmation of informed patient consent for publication was obtained.
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) | 0,001 | 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 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
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 ».