Abstract | INTRODUCTION: The electrocardiographic index Tpeak-Tend has been proposed as a marker of dispersion of repolarization and may be a stronger predictor of torsade de pointes risk than QTc prolongation. METHODS AND RESULTS: We assessed whether quinidine-induced Tpeak-Tend prolongation is greater in women than men. The relationship between QTc prolongation and quinidine concentration was greater in women than men (38 ± 10 vs. 28 ± 9 ms/μg/ml, p=0.02), but there was no difference for Tpeak-Tend prolongation (39 ± 13 vs. 32 ± 13 ms/μg/ml, p=0.21). There was a delay (hysteresis) between peak concentration and both maximum QTc and Tpeak-Tend prolongation and a trend toward higher serum quinidine concentration in men than women. Analysis controlling for hysteresis showed no sex difference for QTc (55 ± 18 vs. 43 ± 19 ms/μg/ml, p=0.14), without changing the lack of sex difference with Tpeak-Tend (61 ± 22 vs. 55 ± 21 ms/μg/ml, p=0.49). CONCLUSIONS: Women do not have a greater quinidine-induced Tpeak-Tend prolongation than men. Sex differences in hysteresis and serum quinidine concentration in this study may have contributed to sex differences in quinidine-induced QTc prolongation.
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Authors | Jose Vicente, Jacob Simlund, Lars Johannesen, Frida Sundh, Jeffry Florian, Martin Ugander, Galen S Wagner, Raymond L Woosley, David G Strauss |
Journal | Journal of electrocardiology
(J Electrocardiol)
2015 Jul-Aug
Vol. 48
Issue 4
Pg. 533-8
ISSN: 1532-8430 [Electronic] United States |
PMID | 25796102
(Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
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Copyright | Published by Elsevier Inc. |
Chemical References |
- Anti-Arrhythmia Agents
- Quinidine
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Topics |
- Adolescent
- Adult
- Anti-Arrhythmia Agents
(administration & dosage, adverse effects, pharmacokinetics)
- Dose-Response Relationship, Drug
- Electrocardiography
(drug effects)
- Feasibility Studies
- Female
- Humans
- Male
- Quinidine
(administration & dosage, adverse effects, blood)
- Reproducibility of Results
- Risk Assessment
(methods)
- Sensitivity and Specificity
- Sex Factors
- Single-Blind Method
- Torsades de Pointes
(blood, chemically induced, diagnosis)
- Young Adult
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