Overdrive pacing of early ischemic ventricular tachycardia: evidence for both reentry and triggered activity

2.50
Hdl Handle:
http://hdl.handle.net/2336/64954
Title:
Overdrive pacing of early ischemic ventricular tachycardia: evidence for both reentry and triggered activity
Authors:
Arnar, David O; Xing, Dezhi; Martins, James B
Citation:
Am. J. Physiol. Heart Circ. Physiol. 2005, 288(3):H1124-30
Issue Date:
1-Mar-2005
Abstract:
Entrainment can be a useful method to identify reentry as a mechanism of ventricular tachycardia (VT). In this study, we evaluated the effect of gradually decreasing cycle lengths of overdrive pacing for stable VT induced in a canine model 1-3 h after coronary occlusion. Intact dogs underwent anterior descending coronary artery occlusion after instrumentation of the risk zone with 21 multipolar plunge needles, each recording 6 bipolar electrograms. Overdrive pacing was attempted if the animals had sustained hemodynamically stable VT, looking for evidence of entrainment. Subsequent three-dimensional mapping determined the mechanism of VT. Fifteen of the 21 dogs studied demonstrated entrainment with overdrive pacing by progressive QRS fusion alone (1), the first nonpaced QRS entrained to the paced cycle length only (7), or both (7). Five of these 15 dogs also had postpacing acceleration of the VT at a subsequent faster pacing cycle length. The mechanism of acceleration in four was a change to a VT with a focal origin. The prepacing mechanism in all 15 dogs was subsequently mapped to reentry. Regarding the six VTs, which demonstrated no evidence for entrainment, the site of earliest activity was mapped to a focal origin in all. These data showing entrainment of inducible reentrant VTs and lack of such for focal VTs support that the focal VTs seen in this study are unlikely the result of microreentry but possibly a mechanism as triggered activity.
Description:
To access publisher full text version of this article. Please click on the hyperlink in Additional Links field
Additional Links:
http://ajpheart.physiology.org/cgi/content/abstract/288/3/H1124

Full metadata record

DC FieldValue Language
dc.contributor.authorArnar, David O-
dc.contributor.authorXing, Dezhi-
dc.contributor.authorMartins, James B-
dc.date.accessioned2009-04-15T09:32:32Z-
dc.date.available2009-04-15T09:32:32Z-
dc.date.issued2005-03-01-
dc.date.submitted2009-04-15-
dc.identifier.citationAm. J. Physiol. Heart Circ. Physiol. 2005, 288(3):H1124-30en
dc.identifier.issn0363-6135-
dc.identifier.pmid15706044-
dc.identifier.doi10.1152/ajpheart.01162.2003-
dc.identifier.urihttp://hdl.handle.net/2336/64954-
dc.descriptionTo access publisher full text version of this article. Please click on the hyperlink in Additional Links fielden
dc.description.abstractEntrainment can be a useful method to identify reentry as a mechanism of ventricular tachycardia (VT). In this study, we evaluated the effect of gradually decreasing cycle lengths of overdrive pacing for stable VT induced in a canine model 1-3 h after coronary occlusion. Intact dogs underwent anterior descending coronary artery occlusion after instrumentation of the risk zone with 21 multipolar plunge needles, each recording 6 bipolar electrograms. Overdrive pacing was attempted if the animals had sustained hemodynamically stable VT, looking for evidence of entrainment. Subsequent three-dimensional mapping determined the mechanism of VT. Fifteen of the 21 dogs studied demonstrated entrainment with overdrive pacing by progressive QRS fusion alone (1), the first nonpaced QRS entrained to the paced cycle length only (7), or both (7). Five of these 15 dogs also had postpacing acceleration of the VT at a subsequent faster pacing cycle length. The mechanism of acceleration in four was a change to a VT with a focal origin. The prepacing mechanism in all 15 dogs was subsequently mapped to reentry. Regarding the six VTs, which demonstrated no evidence for entrainment, the site of earliest activity was mapped to a focal origin in all. These data showing entrainment of inducible reentrant VTs and lack of such for focal VTs support that the focal VTs seen in this study are unlikely the result of microreentry but possibly a mechanism as triggered activity.en
dc.language.isoenen
dc.publisherAmerican Physiological Societyen
dc.relation.urlhttp://ajpheart.physiology.org/cgi/content/abstract/288/3/H1124en
dc.subject.meshAnimalsen
dc.subject.meshDogsen
dc.subject.meshFemaleen
dc.subject.meshHearten
dc.subject.meshHeart Ventriclesen
dc.subject.meshMaleen
dc.subject.meshMyocardial Ischemiaen
dc.subject.meshPacemaker, Artificialen
dc.subject.meshTachycardia, Ventricularen
dc.subject.meshVentricular Fibrillationen
dc.titleOverdrive pacing of early ischemic ventricular tachycardia: evidence for both reentry and triggered activityen
dc.typeArticleen
dc.contributor.departmentDivision of Cardiovascular Diseases, Department of Internal Medicine, University of Iowa College of Medicine and Veterans Administration Medical Center, Iowa City, USA.en
dc.identifier.journalAmerican journal of physiology. Heart and circulatory physiologyen
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