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21. |
Effects of Antiarrhythmic Drugs on Fibrillation in the Remodeled AtriumInsights Into the Mechanism of the Superior Efficacy of Amiodarone |
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Circulation: Journal of the American Heart Association,
Volume 107,
Issue 10,
2003,
Page 1440-1446
Kaori Shinagawa,
Akiko Shiroshita-Takeshita,
Gernot Schram,
Stanley Nattel,
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摘要:
Background—The basis of the unique effectiveness of amiodarone for atrial fibrillation (AF) is poorly understood. The present study tested the hypothesis that amiodarone blocks electrical remodeling induced by atrial tachycardia.Methods and Results—Mongrel dogs were subjected to atrial tachycardia (400 bpm for 7 days) in the absence and presence of therapy with amiodarone, the class III cardiac antiarrhythmic drug dofetilide, or the class I agent flecainide begun 3 days before the onset of tachypacing and maintained until a final electrophysiological study. AF vulnerability (percentage of sites with AF induction by single premature extrastimuli), mean AF duration, atrial effective refractory period (ERP), and conduction velocity were compared among these dogs and in unpaced dogs in the absence or presence of treatment with the same agents. Only amiodarone prevented promotion of AF duration and vulnerability by atrial tachycardia. Furthermore, only amiodarone eliminated tachycardia-induced ERP abbreviation and loss of ERP rate adaptation while obviating L-type Ca2+-current &agr;1c-subunit downregulation as determined by Western blot. In an additional series of dogs monitored with repeated electrophysiological studies, amiodarone administered after the induction of atrial tachycardia remodeling reversed remodeling within several days, despite continued atrial tachypacing during amiodarone therapy.Conclusions—Amiodarone is uniquely effective against AF promotion by atrial tachycardia remodeling in this experimental model and prevents electrophysiological and biochemical consequences of remodeling. Amiodarone also reversed remodeling established by 4 days of atrial tachycardia. The inhibition of atrial tachycardia remodeling may therefore contribute to the superior efficacy of amiodarone in AF.
ISSN:0009-7322
出版商:OVID
年代:2003
数据来源: OVID
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22. |
Late Internal Mammary Arteriovenous Fistula |
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Circulation: Journal of the American Heart Association,
Volume 107,
Issue 10,
2003,
Page 1447-1447
Krishna Kathir,
Richmond Jeremy,
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PDF (82KB)
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ISSN:0009-7322
出版商:OVID
年代:2003
数据来源: OVID
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23. |
Obesity, Insulin Resistance, Diabetes, and Cardiovascular Risk in ChildrenAn American Heart Association Scientific Statement From the Atherosclerosis, Hypertension, and Obesity in the Young Committee (Council on Cardiovascular Disease in the Young) and the Diabetes Committee (Council on Nutrition, Physical Activity, and Metabolism) |
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Circulation: Journal of the American Heart Association,
Volume 107,
Issue 10,
2003,
Page 1448-1453
Julia Steinberger,
Stephen Daniels,
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PDF (40KB)
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ISSN:0009-7322
出版商:OVID
年代:2003
数据来源: OVID
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24. |
Cardiovascular News |
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Circulation: Journal of the American Heart Association,
Volume 107,
Issue 10,
2003,
Page 9018-9019
Ruth SoRelle,
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ISSN:0009-7322
出版商:OVID
年代:2003
数据来源: OVID
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