Activation of electrical triggers of atrial fibrillation in hyperthyroidism.

Détails

ID Serval
serval:BIB_E4314ED33B38
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Activation of electrical triggers of atrial fibrillation in hyperthyroidism.
Périodique
Journal of Clinical Endocrinology and Metabolism
Auteur(s)
Wustmann K., Kucera J.P., Zanchi A., Burow A., Stuber T., Chappuis B., Diem P., Delacrétaz E.
ISSN
0021-972X
Statut éditorial
Publié
Date de publication
2008
Peer-reviewed
Oui
Volume
93
Numéro
6
Pages
2104-2108
Langue
anglais
Résumé
CONTEXT: A shortening of the atrial refractory period has been considered as the main mechanism for the increased risk of atrial fibrillation in hyperthyroidism. However, other important factors may be involved. OBJECTIVE: Our objective was to determine the activity of abnormal supraventricular electrical depolarizations in response to elevated thyroid hormones in patients without structural heart disease. PATIENTS AND DESIGN: Twenty-eight patients (25 females, three males, mean age 43+/-11 yr) with newly diagnosed and untreated hyperthyroidism were enrolled in a prospective trial after exclusion of heart disease. Patients were followed up for 16 +/- 6 months and studied at baseline and 6 months after normalization of serum TSH levels. MAIN OUTCOME MEASURES: The incidence of abnormal premature supraventricular depolarizations (SVPD) and the number of episodes of supraventricular tachycardia was defined as primary outcome measurements before the start of the study. In addition, heart rate oscillations (turbulence) after premature depolarizations and heart rate variability were compared at baseline and follow-up. RESULTS: SVPDs decreased from 59 +/- 29 to 21 +/- 8 per 24 h (P = 0.003), very early SVPDs (so called P on T) decreased from 36 +/- 24 to 3 +/- 1 per 24 h (P < 0.0001), respectively, and nonsustained supraventricular tachycardias decreased from 22 +/- 11 to 0.5 +/- 0.2 per 24 h (P = 0.01) after normalization of serum thyrotropin levels. The hyperthyroid phase was characterized by an increased heart rate (93 +/- 14 vs. 79 +/- 8 beats/min, P < 0.0001) and a decreased turbulence slope (3.6 vs. 9.2, P = 0.003), consistent with decreased vagal tone. This was confirmed by a significant decrease of heart rate variability. CONCLUSION: Hyperthyroidism is associated with an increased supraventricular ectopic activity in patients with normal hearts. The activation of these arrhythmogenic foci by elevated thyroid hormones may be an important causal link between hyperthyroidism and atrial fibrillation.
Mots-clé
Action Potentials/physiology, Adult, Antithyroid Agents/therapeutic use, Atrial Fibrillation/etiology, Atrial Fibrillation/physiopathology, Carbimazole/therapeutic use, Echocardiography, Electric Stimulation, Female, Heart Rate/drug effects, Heart Rate/physiology, Humans, Hyperthyroidism/complications, Hyperthyroidism/drug therapy, Male, Middle Aged, Propylthiouracil/therapeutic use, Tachycardia, Supraventricular/etiology
Pubmed
Web of science
Open Access
Oui
Création de la notice
14/10/2009 10:19
Dernière modification de la notice
20/08/2019 16:07
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