Document Detail


Ventricular ectopy during treadmill exercise stress testing in the evaluation of long QT syndrome.
MedLine Citation:
PMID:  19084807     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Long QT syndrome (LQTS) can present with sudden death during exertion.
OBJECTIVE: The purpose of this study was to determine the diagnostic importance of exercise-induced ventricular ectopy in the evaluation of LQTS.
METHODS: From 1998 to 2006, 381 patients with a referral diagnosis of LQTS underwent a treadmill exercise stress test. An investigator blinded to both genotype and rendered diagnosis scored the stress tests for the presence of exercise-induced ventricular ectopy.
RESULTS: The dismissal diagnosis was LQTS in 177 (46%), catecholaminergic polymorphic ventricular tachycardia (CPVT) in 16, miscellaneous cardiac disease in 17, and normal in 171. Exercise-induced ventricular ectopy was detected in 107 (28%) patients. However, only 34 patients (9% overall) had exercise-induced ventricular ectopy greater than single premature ventricular contractions (PVCs). Among the 171 patients dismissed as normal, only 2% had ectopy greater than single PVCs. Among the genotype-positive LQTS patients, no significant ectopy was recorded in 80 with LQT1, compared to 5 (8%) patients with LQT2 and 3 (20%) patients with LQT3 (P <.0001). In contrast, exercise-induced ventricular ectopy beyond single PVCs was far more common among patients with CPVT (14/16 [88%]; P <.0001) and included PVCs in bigeminy in 13 (81%), couplets in 7 (47%), and nonsustained ventricular tachycardia in 3 (19%). Of note, bidirectional VT was not present in any of the 16 patients diagnosed with CPVT, including the 10 with genetically proven, RYR2-mediated CPVT.
CONCLUSION: Exercise-induced ventricular ectopy exceeding single PVCs was observed in less than 10% of patients referred for LQTS evaluation, including 2% of patients ultimately dismissed as normal. Exercise-induced bigeminy is strongly associated with the presence of significant cardiovascular disease but is far more likely to indicate CPVT than LQTS.
Authors:
Justin M Horner; Michael J Ackerman
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2008-09-04
Journal Detail:
Title:  Heart rhythm : the official journal of the Heart Rhythm Society     Volume:  5     ISSN:  1556-3871     ISO Abbreviation:  Heart Rhythm     Publication Date:  2008 Dec 
Date Detail:
Created Date:  2008-12-16     Completed Date:  2009-04-07     Revised Date:  2012-02-20    
Medline Journal Info:
Nlm Unique ID:  101200317     Medline TA:  Heart Rhythm     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1690-4     Citation Subset:  IM    
Affiliation:
Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota 55905, USA.
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MeSH Terms
Descriptor/Qualifier:
Diagnosis, Differential
Electrocardiography*
Exercise Test / adverse effects*
Female
Follow-Up Studies
Heart Rate / physiology
Humans
Long QT Syndrome / diagnosis*,  physiopathology
Male
Prognosis
Retrospective Studies
Ventricular Premature Complexes / diagnosis,  etiology*,  physiopathology
Young Adult
Grant Support
ID/Acronym/Agency:
HD42569/HD/NICHD NIH HHS; KL2 RR024151-06/RR/NCRR NIH HHS

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


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