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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
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pubmed:dateCreated |
1992-9-24
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pubmed:abstractText |
Amiodarone produces use-dependent block of cardiac sodium channels in vitro. This study assessed whether similar use-dependent block occurred in 19 patients with coronary artery disease and inducible, sustained, monomorphic ventricular tachycardia treated with amiodarone. Beat-to-beat measurements of ventricular paced QRS durations during 12-beat trains at cycle lengths of 700, 600, 400 and 300 ms were analyzed at a baseline antiarrhythmic drug-free study and after 2 and 10 weeks of amiodarone therapy. At the drug-free study, there were no significant changes in paced QRS durations within the 12-beat trains at any pacing cycle lengths. After 2 and 10 weeks of amiodarone therapy, progressive prolongation of paced QRS durations occurred over the 12-beat trains at pacing cycle lengths of 600, 400 and 300 ms (p less than 0.05). Significant changes in QRS duration were not observed at a pacing cycle length of 700 ms. This progressive prolongation in QRS duration can be fitted as a function of beat number to a monoexponential equation and occurred with an onset time constant of 1.02 +/- 0.41 beats (306 +/- 122 ms) at a pacing cycle length of 300 ms. The magnitude of QRS prolongation increased as the pacing cycle length was shortened. The magnitudes of QRS prolongation were similar after 2 and 10 weeks of amiodarone therapy. In conclusion, use-dependent prolongation in QRS duration occurs at rapid pacing cycle lengths in humans receiving amiodarone.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
AIM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0002-9149
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
70
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
598-604
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:1324598-Amiodarone,
pubmed-meshheading:1324598-Cardiac Pacing, Artificial,
pubmed-meshheading:1324598-Coronary Disease,
pubmed-meshheading:1324598-Electrocardiography,
pubmed-meshheading:1324598-Female,
pubmed-meshheading:1324598-Heart Conduction System,
pubmed-meshheading:1324598-Humans,
pubmed-meshheading:1324598-Male,
pubmed-meshheading:1324598-Middle Aged,
pubmed-meshheading:1324598-Regression Analysis,
pubmed-meshheading:1324598-Sodium Channels,
pubmed-meshheading:1324598-Tachycardia,
pubmed-meshheading:1324598-Time Factors
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pubmed:year |
1992
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pubmed:articleTitle |
Use-dependent electrophysiologic effects of amiodarone in coronary artery disease and inducible ventricular tachycardia.
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pubmed:affiliation |
Department of Medicine, University of Calgary, Alberta, Canada.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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