Document Detail

Modification of the circadian pattern of ventricular tachyarrhythmias by beta-blocker therapy.
MedLine Citation:
PMID:  9068912     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Sudden cardiac death exhibits a circadian variation and predominantly occurs during morning hours, Beta-adrenergic antagonists have shown to blunt this morning peak. However, previous reports studying the effects of beta blockers on the circadian variation did not analyze the underlying cause of sudden cardiac death. It thus remains unclear whether ventricular tachyarrhythmias are influenced by beta-blocker therapy. HYPOTHESIS: This study tested the hypothesis that beta-blocking agents blunt the morning peak of life-threatening ventricular tachyarrhythmias. METHODS: In 87 patients who were treated and monitored with an implantable cardioverter defibrillator, the circadian distribution of ventricular tachyarrhythmias terminated by appropriate shocks was analyzed and compared in those receiving beta blockers versus those not receiving beta-blocker therapy. RESULTS: Tachyarrhythmic episodes in the absence of beta-blocker therapy (n = 344) exhibited a circadian variation with a distinct morning peak (16, 38, 28, and 18% of episodes at 0-6, 6-12, 12-18, and 18-24 h, respectively, p < 0.001). In contrast, tachyarrhythmic episodes during beta-blocker therapy (n = 104) were equally distributed over time (22, 27, 24, and 27% of episodes at 0-6, 6-12, 12-18, and 18-24 h, respectively, p = 0.95). The circadian distribution of episodes was significantly different in patients with and those without beta blockade (p < 0.05). CONCLUSION: Beta-adrenergic antagonists influence the circadian distribution of malignant ventricular tachyarrhythmias in patients with an implantable cardioverter defibrillator. The blunted morning peak of tachyarrhythmic events during beta blockade supports the hypothesis that a sympathetic surge is involved in the circadian pattern of malignant arrhythmias.
S Behrens; C Ehlers; T Brüggemann; W Ziss; R Dissmann; M Galecka; S N Willich; D Andresen
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Clinical cardiology     Volume:  20     ISSN:  0160-9289     ISO Abbreviation:  Clin Cardiol     Publication Date:  1997 Mar 
Date Detail:
Created Date:  1997-05-23     Completed Date:  1997-05-23     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  7903272     Medline TA:  Clin Cardiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  253-7     Citation Subset:  IM    
Department of Cardiology and Pulmology, Klinikum Benjamin Franklin, Free University, Berlin, Germany.
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MeSH Terms
Adrenergic beta-Antagonists / therapeutic use*
Circadian Rhythm*
Death, Sudden, Cardiac / epidemiology,  etiology
Defibrillators, Implantable
Middle Aged
Tachycardia, Ventricular / drug therapy,  physiopathology*,  therapy
Ventricular Fibrillation / drug therapy,  physiopathology*,  therapy
Reg. No./Substance:
0/Adrenergic beta-Antagonists

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