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Effect of ischemic zone size on nonischemic zone function
- Source :
- Scopus-Elsevier
-
Abstract
- To study the influence of ischemic zone size on function in nonischemic regions, wall thickening and the end-systolic pressure-thickness (ESPTR) relationship were measured before and during a 90-s coronary occlusion, which produced either a small or large (24 or 35% of left ventricular mass) area of ischemia. With both size ischemic areas, nonischemic zone isovolumic and ejection phase wall thickening increased during occlusion, primarily because of increased preload and, to a lesser extent, a reduced pressure component of afterload. The nonischemic region ESPTR was unchanged from preocclusion control with small ischemic mass. With larger ischemic mass, the nonischemic region ESPTR was shifted downward and to the left, indicating reduced end-systolic performance. The decline in the nonischemic zone ESPTR with large ischemic zone size was not due to reduced blood flow, shortening deactivation, reflex effects, or "tethering" but rather to the associated decline in coronary perfusion pressure. Thus the increase of nonischemic region wall thickening during acute ischemia is due to a change in ventricular loading conditions and not augmentation of contractile performance. Larger ischemic zone size can impair function in nonischemic myocardium by reducing the erectile component of end-systolic performance.
- Subjects :
- Male
medicine.medical_specialty
Systole
Physiology
Adrenergic beta-Antagonists
Ischemia
Hemodynamics
Blood Pressure
Coronary Disease
Dogs
Afterload
Physiology (medical)
Internal medicine
medicine
Animals
business.industry
Myocardium
Heart
medicine.disease
Preload
Coronary occlusion
Anesthesia
Circulatory system
Cardiology
Coronary perfusion pressure
Female
Cardiology and Cardiovascular Medicine
business
Subjects
Details
- Database :
- OpenAIRE
- Journal :
- Scopus-Elsevier
- Accession number :
- edsair.doi.dedup.....e5f112d7d05241222719ade8a3d9cdf2