β-Blockers Protect Against Dispersion of Repolarization During Exercise in Congenital Long-QT Syndrome Type 1.
Dispersion of Repolarization in LQT1. Introduction:β-Blocker therapy reduces syncope and sudden death in long-QT syndrome type 1 (LQT1), but the mechanism of protection is incompletely understood. This study tested the hypothesis that β-blockade reduces QT prolongation and dispersion of repolarizat...
| Publicado en: | Journal of Cardiovascular Electrophysiology Vol. 22; no. 10; pp. 1141 - 1147 |
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| Autores principales: | , , , , , , |
| Formato: | research tables/charts tracings Journal Article |
| Publicado: |
Wiley-Blackwell
Oct2011
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=66394209&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 66394209 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 10453873 GSB jtl: Journal of Cardiovascular Electrophysiology issn: 10453873 maglogo: Y pubinfo: dt: Oct2011 vid: 22 iid: 10 pid: 480 pub: Wiley-Blackwell place: Malden, Massachusetts artinfo: ui: 66394209 104698966 104698966 10.1111/j.1540-8167.2011.02091.x 66394209 ppf: 1141 ppct: 6 formats: fmt: – @attributes: type: T – @attributes: type: P tig: atl: β-Blockers Protect Against Dispersion of Repolarization During Exercise in Congenital Long-QT Syndrome Type 1. aug: au: GEMMA, LEE W. WARD, GREGORY M. DETTMER, MARY M. BALL, JENNIFER L. LEO, PETER J. DORIA, DANIELLE N. KAUFMAN, ELIZABETH S. affil: Heart and Vascular Research Center, MetroHealth Campus of Case Western Reserve University, Cleveland, Ohio, USA sug: subj: Long QT Syndrome Familial and Genetic Adrenergic beta-Antagonists Pharmacodynamics Long QT Syndrome Physiopathology Long QT Syndrome Drug Therapy Exercise Test, Cardiopulmonary Human Funding Source Male Female Adult Middle Age Descriptive Statistics Adrenergic beta-Antagonists Administration and Dosage Electrocardiography Paired T-Tests Treatment Outcomes Heart Rate Adult: 19-44 years Middle Aged: 45-64 years Male Female ab: Dispersion of Repolarization in LQT1. Introduction:β-Blocker therapy reduces syncope and sudden death in long-QT syndrome type 1 (LQT1), but the mechanism of protection is incompletely understood. This study tested the hypothesis that β-blockade reduces QT prolongation and dispersion of repolarization, measured as the T peak-to-end interval (Tpe), during exercise and recovery in LQT1 patients. Methods and Results: QT and Tpe were measured in 10 LQT1 patients (33 ± 13 years) and 35 normal subjects (32 ± 12 years) during exercise tests on and off β-blockade. In LQT1 patients, β-blockade reduced QT (391 ± 25 milliseconds vs 375 ± 26 milliseconds, P = 0.04 during exercise; 419 ± 41 milliseconds vs 391 ± 39 milliseconds, P = 0.02 during recovery) and markedly reduced Tpe (91 ± 26 milliseconds vs 67 ± 19 milliseconds, P = 0.03 during exercise; 103 ± 26 milliseconds vs 78 ± 11 milliseconds, P = 0.02 during recovery). In contrast, in normal subjects, β-blockade had no effect on QT (320 ± 17 milliseconds vs 317 ± 16 milliseconds, P = 0.29 during exercise; 317 ± 13 milliseconds vs 315 ± 14 milliseconds, P = 0.15 during recovery) and mildly reduced Tpe (69 ± 13 milliseconds vs 61 ± 11 milliseconds, P = 0.01 during exercise; 77 ± 19 milliseconds vs. 68 ± 14 milliseconds, P < 0.001 during recovery). Conclusion: In LQT1 patients, β-blockers reduced QT and Tpe during exercise and recovery, supporting the theory that β-blocker therapy protects LQT1 patients by reducing dispersion of repolarization during exercise and recovery. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1141-1146, October 2011) pubtype: Academic Journal doctype: research tables/charts tracings Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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