| Rate-independent QT shortening during exercise in healthy subjects: terminal repolarization does not shorten with exercise. | |
| | |
MedLine Citation:
|
PMID: 18665873 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
INTRODUCTION: QT interval for a given heart rate differs between exercise and recovery (QT hysteresis) due to slow QT adaptation to changes in heart rate. We hypothesized that QT hysteresis is evident within stages of exercise and investigated which component of the QT contributes to hysteresis. METHODS AND RESULTS: Nineteen healthy volunteers performed a staged exercise test (four stages, 3 min each). Continuous telemetry was analyzed with software to compare QT intervals in a rate-independent fashion. QRST complexes during each minute were sorted by RR interval, and complexes in bins of 20 ms width were signal-averaged. QT and QTp (onset of QRS to peak T wave) were measured, and terminal QT calculated (peak to end of T wave, Tpe = QT - QTp). QT, QTp, and Tpe at the same heart rate were compared between the first and last minute of each stage. QT shortened from the first to last minute of exercise in each stage (Stage I: 358 +/- 30 to 346 +/- 25 ms, P < 0.001; Stage II: 342 +/- 27 to 331 +/- 24 ms, P = 0.003; Stage III: 329 +/- 21 to 322 +/- 18 ms, P = 0.03; Stage IV: 313 +/- 22 to 303 +/- 23 ms, P = 0.005). QTp also shortened in each stage, while Tpe was unchanged. CONCLUSION: QT hysteresis occurs during exercise in normals, and the major determinant is shortening of the first component of the T wave. Terminal repolarization (peak to end of T wave), a surrogate for transmural dispersion of repolarization, does not shorten significantly with exercise. |
| | |
Authors:
|
Prince J Kannankeril; Paul A Harris; Kris J Norris; Irfan Warsy; Phillip D Smith; Dan M Roden |
Related Documents
:
|
18468283 - Reducing rapid eating in teenagers with autism: use of a pager prompt. 9826863 - Comparison of normal sinus rhythm and pacing rate in children with minute ventilation s... 8421973 - Transient myocardial ischemia after a first acute myocardial infarction and its relatio... |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural Date: 2008-07-28 |
Journal Detail:
|
Title: Journal of cardiovascular electrophysiology Volume: 19 ISSN: 1540-8167 ISO Abbreviation: J. Cardiovasc. Electrophysiol. Publication Date: 2008 Dec |
Date Detail:
|
Created Date: 2009-01-05 Completed Date: 2009-03-16 Revised Date: 2011-09-26 |
Medline Journal Info:
|
Nlm Unique ID: 9010756 Medline TA: J Cardiovasc Electrophysiol Country: United States |
Other Details:
|
Languages: eng Pagination: 1284-8 Citation Subset: IM |
Affiliation:
|
Oates Institute for Experimental Therapeutics, Clinical Research Center, Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, Tennessee 37232-9119, USA. prince.kannankeril@vanderbilt.edu |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adolescent Adult Electrocardiography / methods* Female Heart Conduction System / physiology* Heart Rate / physiology* Humans Male Physical Exertion / physiology* Reference Values Young Adult |
| Grant Support | |
ID/Acronym/Agency:
|
HL076264/HL/NHLBI NIH HHS; HL65962/HL/NHLBI NIH HHS; K23 HL076264-01A2/HL/NHLBI NIH HHS; RR-00095/RR/NCRR NIH HHS; RR024975/RR/NCRR NIH HHS |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Results of a residential indoor PM2.5 sampling program before and after a woodstove changeout.
Next Document: Regional endocardial left atrial voltage and electrogram fractionation in patients with atrial fibri...