| Utility of the recovery electrocardiogram after exercise: a novel indicator for the diagnosis and genotyping of long QT syndrome? | |
| | |
MedLine Citation:
|
PMID: 20226272 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
BACKGROUND: Exercise testing has shown modest utility in the ability to diagnose and genotype long QT syndrome (LQTS). Although numerous small studies have shown a genotype-specific repolarization response to exercise, the repolarization responses during recovery from exercise have received less focus. OBJECTIVE: The purpose of this study was to characterize genotype-specific QT responses during recovery from exercise and to determine its potential as a diagnostic and genotyping tool. METHODS: Seventy-five patients were age and sex matched into three groups (n = 25): LQT1, LQT2, and unaffected controls based on Schwartz score and genetic testing results. Each group underwent upright burst and gradual bicycle exercise testing while being monitored by 12-lead electrocardiogram. RESULTS: LQT1 patients had significantly longer corrected QT (QTc) than LQT2 intervals during early recovery (P <.01). Control subjects showed little variation in QTc throughout the recovery period, maintaining a QTc within normal limits. Each group showed a distinct pattern of QTc adaptation during recovery. LQT1 patients began the recovery period at a QTc of 492 +/- 11 ms, after which the QTc decreased by 33 +/- 11 ms during recovery. Conversely, the LQT2 patients began recovery at its lowest mean QTc of 420 +/- 10 ms, which increased by 40 +/- 16 ms. At the end of recovery, a QTc cut-off value of 445 ms distinguished 92% of LQTS patients from unaffected controls, while a start-of-recovery QTc cut-off of 460 ms correctly identified genotype in 80% of LQT1 and 92% of LQT2 patients. CONCLUSIONS: Genotype-specific differences exist in QT recovery after exercise. These differences can help to identify LQTS patients and distinguish LQT1 from LQT2 genotypes. |
| | |
Authors:
|
Ishvinder S Chattha; Raymond W Sy; Raymond Yee; Lorne J Gula; Allan C Skanes; George J Klein; Matthew T Bennett; Andrew D Krahn |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-03-10 |
Journal Detail:
|
Title: Heart rhythm : the official journal of the Heart Rhythm Society Volume: 7 ISSN: 1556-3871 ISO Abbreviation: Heart Rhythm Publication Date: 2010 Jul |
Date Detail:
|
Created Date: 2010-07-15 Completed Date: 2010-11-22 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 101200317 Medline TA: Heart Rhythm Country: United States |
Other Details:
|
Languages: eng Pagination: 906-11 Citation Subset: IM |
Copyright Information:
|
Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved. |
Affiliation:
|
Division of Cardiology, University of Western Ontario, London, Ontario, Canada. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adaptation, Physiological Adolescent Adult Aged Child Electrocardiography Exercise / physiology* Exercise Test Female Genotype Humans Long QT Syndrome / genetics* Male Middle Aged Young Adult |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Evolution of the Sequence Ontology terms and relationships.
Next Document: Succinate dehydrogenase - Assembly, regulation and role in human disease.