| Differing mechanisms for ventricular vulnerability during coronary artery occlusion and release. | |
| | |
MedLine Citation:
|
PMID: 941834 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
The time course and mechanism of vulnerability to ventricular fibrillation (VF) a 10-minute occlusion of the left anterior descending coronary artery and following its release were studied in 48 dogs. VF threshold was determined by inducing a sequence of three extrasystoles (sequential R/T pulsing). Within 1 minute of occlusion, the fibrillation current decreased to the level required for eliciting a propagated diastolic response. This state of enhanced vulnerability lasted for approximately 6 minutes, after which the VF threshold returned to preocclusion values. The vulnerability changes upon reperfusion, by comparison, occurred within seconds of release and persisted only transiently. Three minutes of occlusion was the minimal time which resulted in a reduction in VF threshold after release. Alpha and beta-adrenergic blockade with phentolamine and propranolol, respectively, prevented the decrease in VF threshold during occlusion but were without effect upon threshold changes during coronary artery release. Lidocaine failed to alter the pattern of vulnerability. It is concluded that adrenergic mechanisms play a key role in the increased susceptibility to VF associated with acute myocardial ischemia, whereas the changes in VF threshold following reperfusion may be due to washout products of cellular ischemia. These findings support the view that protection against VF during coronary artery occlusion and release may require different antiarrhythmic measures. |
| | |
Authors:
|
R Corbalan; R L Verrier; B Lown |
Related Documents
:
|
6503254 - Transventricular simple-capacitor discharge defibrillation thresholds after coronary li... 17926944 - Femoropopliteal artery centerline interpolation using contralateral shape. 6644214 - Real-time measurement of the spatial magnitude of the st segment with the automated vec... 6194564 - Pulmonary veno-occlusive disease due to bleomycin therapy for lymphoma. case reports. 11549304 - Transcatheter coil occlusion of the arterial duct; results of the european registry. 20217064 - Echocardiographic and three-dimensional computed tomographic diagnosis of crossed pulmo... |
Publication Detail:
|
Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
|
Title: American heart journal Volume: 92 ISSN: 0002-8703 ISO Abbreviation: Am. Heart J. Publication Date: 1976 Aug |
Date Detail:
|
Created Date: 1976-09-25 Completed Date: 1976-09-25 Revised Date: 2006-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0370465 Medline TA: Am Heart J Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 223-30 Citation Subset: AIM; IM |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Coronary Circulation* Coronary Disease / complications, physiopathology* Dogs Female Heart / physiopathology* Lidocaine / therapeutic use Male Phentolamine / therapeutic use Propranolol / therapeutic use Ventricular Fibrillation / drug therapy, physiopathology*, prevention & control |
| Chemical | |
Reg. No./Substance:
|
137-58-6/Lidocaine; 50-60-2/Phentolamine; 525-66-6/Propranolol |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: The effect of isosorbide dinitrate following experimental coronary occlusion.
Next Document: Clinical evaluation of aortic and mitral valve prostheses.