Journal article
Implantable cardioverter-defibrillator shocks increase T-wave alternans
Journal of cardiovascular electrophysiology, Vol.18(5), pp.512-517
05/2007
DOI: 10.1111/j.1540-8167.2007.00787.x
PMID: 17428273
Abstract
While implantable defibrillator shocks save lives, shock can lead to ventricular arrhythmias. However, the mechanism of shock-related proarrhythmia remains unclear. We evaluated the impact of ICD shock on repolarization instability, a factor associated with ventricular arrhythmogenesis.
Sixty-five patients with ICDs underwent ambulatory ECG monitoring during defibrillation testing 3 months postimplant. TWA was analyzed continuously in the time domain during baseline, sedated, and post-shock states. RR, QRS, and QT intervals and catecholamines were also measured continuously. Adequate pre- and post-shock Holter data were recorded in 55 patients, 48 male, mean 64 +/- 12 years, 50 with coronary disease, 48 with prior spontaneous or induced arrhythmia. TWA significantly increased after shock, from 9.6 +/- 0.5 to 11.9 +/- 0.6 microV, as did QRS duration, epinephrine, and norepinephrine levels, compared with sedated and baseline states. RR intervals decreased minimally. TWA changes with shock were not associated with RR or QRS duration changes, but were associated with changes in epinephrine.
ICD shock, even in the sedated state, increases repolarization instability as measured by TWA, an effect mediated in part by sympathetic stimulation. This association between shock and TWA may have important mechanistic and clinical implications for optimization of defibrillation therapy.
Details
- Title: Subtitle
- Implantable cardioverter-defibrillator shocks increase T-wave alternans
- Creators
- Rachel Lampert - Department of Medicine, Yale University School of Medicine New Haven, Connecticut, USA. rachel.lampert@yale.eduRobert SouferCraig A McPhersonWilliam P BatsfordStephanie TiradoChristine EarleyAnna GoldbergVladimir Shusterman
- Resource Type
- Journal article
- Publication Details
- Journal of cardiovascular electrophysiology, Vol.18(5), pp.512-517
- DOI
- 10.1111/j.1540-8167.2007.00787.x
- PMID
- 17428273
- ISSN
- 1045-3873
- eISSN
- 1540-8167
- Grant note
- 1R43HL077116-01 / NHLBI NIH HHS M01 RR00125 / NCRR NIH HHS HL071116-01 / NHLBI NIH HHS R01 HL59619-01 / NHLBI NIH HHS
- Language
- English
- Date published
- 05/2007
- Academic Unit
- Cardiovascular Medicine; Internal Medicine
- Record Identifier
- 9984094213102771
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