Document Detail


Drug-induced QT prolongation and proarrhythmia: an inevitable link?
MedLine Citation:
PMID:  17766320     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
One of the most feared potential adverse effects of many drugs is life threatening or fatal arrhythmia--particularly torsade de pointes (TdP) ventricular tachycardia in conjunction with QT prolongation. To fully understand the implications of QT prolongation, it is essential to have an understanding of the ion currents that comprise repolarization and their relation to electrophysiological abnormalities associated with TdP. Also, the QT interval is subject to patient-specific and sometimes idiosyncratic variability. The following questions are addressed: How close is the relationship between QT prolongation and proarrhythmia? How accurately do QT-interval measurements reflect cardiac repolarization? How representative is a single QT measurement with respect to the QT response to a drug? The presumed relationship between the QT interval and myocardial repolarization will be deconstructed, demonstrating that most of the important aspects of repolarization, and subsequent arrhythmogenesis, cannot be understood only through the simple numerical measurement of the QT interval. Repolarization reserve is also discussed. Suggestions for refining the understanding of drug-induced QT prolongation, TdP, and shortcomings of some current definitions are outlined. We speculate on possible future developments in understanding this relationship.
Authors:
Kamran Ahmad; Paul Dorian
Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology     Volume:  9 Suppl 4     ISSN:  1099-5129     ISO Abbreviation:  Europace     Publication Date:  2007 Sep 
Date Detail:
Created Date:  2007-09-03     Completed Date:  2008-02-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100883649     Medline TA:  Europace     Country:  England    
Other Details:
Languages:  eng     Pagination:  iv16-22     Citation Subset:  IM    
Affiliation:
St Michael's Hospital, University of Toronto, 30 Bond Street, 6-050Q, Toronto, Ontario M5B 1W8, Canada.
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MeSH Terms
Descriptor/Qualifier:
Anti-Arrhythmia Agents / pharmacology
Electrocardiography
Heart Conduction System / drug effects,  physiopathology
Humans
Ion Channels / drug effects,  physiology
Long QT Syndrome / chemically induced*,  physiopathology
Torsades de Pointes / chemically induced*,  physiopathology
Chemical
Reg. No./Substance:
0/Anti-Arrhythmia Agents; 0/Ion Channels

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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