High-rate pacing reduces variability of repolarization and prevents repolarization-dependent arrhythmias in dogs with chronic AV block.
Introduction: High-rate pacing may have an inhibitory effect on the initiation of Torsade de Pointes arrhythmias (TdP). However, permanent pacing is only indicated in high-risk patients. We performed a proof of concept study into automatic overdrive pacing for prevention of drug-induced TdP, using s...
| Publicado en: | Journal of Cardiovascular Electrophysiology Vol. 21; no. 12; pp. 1384 - 1392 |
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| Autores principales: | , , , , , , , |
| Formato: | research tables/charts tracings Journal Article |
| Publicado: |
Wiley-Blackwell
Dec2010
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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=104956864&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 104956864 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 10453873 GSB jtl: Journal of Cardiovascular Electrophysiology issn: 10453873 maglogo: Y pubinfo: dt: Dec2010 vid: 21 iid: 12 pid: 480 pub: Wiley-Blackwell place: Malden, Massachusetts artinfo: ui: 104956864 55613957 10.1111/j.1540-8167.2010.01824.x NLM20561108 104956864 ppf: 1384 ppct: 8 formats: fmt: @attributes: type: P tig: atl: High-rate pacing reduces variability of repolarization and prevents repolarization-dependent arrhythmias in dogs with chronic AV block. aug: au: Oosterhoff P Thomsen MB Maas JN Atteveld NJ Beekman JD Van Rijen HVM Van Der Heyden MAG Vos MA affil: Medtronic Bakken Research Center, Maastricht, The Netherlands; m.a.vos@umcutrecht.nl sug: subj: Cardiac Pacing, Artificial Methods Torsades de Pointes Prevention and Control Torsades de Pointes Chemically Induced Heart Block Complications Animal Studies Dogs Heart Conduction System Drug Effects Heart Conduction System Physiopathology Computer Simulation Dofetilide Administration and Dosage Repeated Measures Two-Way Analysis of Variance Post Hoc Analysis Paired T-Tests Wilcoxon Rank Sum Test Descriptive Statistics Heart Rate Funding Source ab: Introduction: High-rate pacing may have an inhibitory effect on the initiation of Torsade de Pointes arrhythmias (TdP). However, permanent pacing is only indicated in high-risk patients. We performed a proof of concept study into automatic overdrive pacing for prevention of drug-induced TdP, using short-term variability of repolarization (STV) as a feedback parameter of arrhythmic risk. Methods and Results: The minimal signal sampling frequency required for measuring STV was determined through computer simulation. Arrhythmogenic response to dofetilide (25 μg/kg/5minutes) was tested at two different paced heart rates (60-65 bpm vs 100-110 bpm) in 7 dogs with chronic atrioventricular block, while recording right and left ventricular (LV) monophasic action potential (MAP) and LV electrogram (EGM). Simulations showed a sampling frequency of 500 Hz is sufficient to capture relevant STV values. High-rate pacing prevented dofetilide-induced TdP seen at the low rate (low: 6/7 vs high: 1/7). At the low rate, STV from LV MAP duration increased before occurrence of spontaneous, ectopic activity and TdP (1.7 ± 0.6-3.0 ± 1.8 ms, P < 0.05), but at the high-rate STV did not change significantly (0.9 ± 0.2-1.5 ± 1.4 ms, NS). Regression analysis showed a close relation between STV calculated from LV MAP and from LV EGM (R= 0.71). Conclusions: High-rate pacing increases repolarization reserve in dogs with chronic atrioventricular block, preventing dofetilide-induced TdP. Changes in repolarization reserve are reflected in values of STV. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1384-1391, December 2010) pubtype: Academic Journal doctype: research tables/charts tracings Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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