Document Detail

Endocardial, intramural, and epicardial activation patterns during sustained monomorphic ventricular tachycardia in late canine myocardial infarction.
MedLine Citation:
PMID:  3594759     Owner:  NLM     Status:  MEDLINE    
Thirteen dogs in whom at least one morphologically distinct sustained ventricular tachycardia (VT) could be reproducibly initiated by programmed cardiac stimulation 18 +/- 3 days following experimental myocardial infarction were placed on total cardiopulmonary bypass for detailed study of the endocardial and epicardial activation during VT under hemodynamically stable conditions. Thirteen morphologically distinct monomorphic VTs were investigated by simultaneous epicardial, endocardial, and intramural bipolar recordings. Local electrograms were used to generate computer-assisted isochronous-activation sequence maps. A complete reentry circuit could be mapped on the epicardial surface in 4 animals and on the endocardial surface in one other animal. In the remaining 8 animals, there was a gap period lasting 43-62 msec in the cardiac cycle during which no endocardial or epicardial activity was observed. In 6 of the 8 animals, bipolar intramural recordings from sites closely associated with regions of endocardial and epicardial conduction block showed intramural activity progressing slowly during the gap period. In these 6 animals, a reentry circuit could be completed by incorporating the local electrograms recorded from the intramural sites. VT could be reproducibly terminated by selectively rendering only these intramural sites refractory by critically timed extrastimuli that failed to result in global ventricular capture. VT could be terminated by epicardial cooling in 2 of the 4 animals with epicardial reentry. By contrast, epicardial cryoablation did not effect intramural reentry and failed to interrupt VT. In this study, intramural pathways constituted an integral part of the reentry circuit in a large proportion of the VTs.
H Garan; J T Fallon; S Rosenthal; J N Ruskin
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Circulation research     Volume:  60     ISSN:  0009-7330     ISO Abbreviation:  Circ. Res.     Publication Date:  1987 Jun 
Date Detail:
Created Date:  1987-08-21     Completed Date:  1987-08-21     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0047103     Medline TA:  Circ Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  879-96     Citation Subset:  IM    
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MeSH Terms
Cardiac Pacing, Artificial
Electric Stimulation
Endocardium / physiopathology*
Heart Ventricles / physiopathology
Myocardial Infarction / physiopathology*
Pericardium / physiopathology*
Tachycardia / physiopathology*
Grant Support

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