Importance of myocardial ischemia for coronary collateral development in conscious dogs
| Autor: | Etsuro Araie, Shigetake Sasayama, Dean Franklin, Kazuto Yamanishi, Masatoshi Fujita, Akira Ohno |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
medicine.medical_specialty
Myocardial ischemia Ischemia Collateral Circulation Coronary Disease Dogs Internal medicine Occlusion medicine Carnivora Animals cardiovascular diseases Reactive hyperemia biology business.industry Myocardium Fissipedia Hemodynamics Collateral circulation medicine.disease biology.organism_classification Constriction Coronary Vessels Anesthesia cardiovascular system Cardiology Ventricular pressure Cardiology and Cardiovascular Medicine business |
| Zdroj: | International Journal of Cardiology. 27:179-186 |
| ISSN: | 0167-5273 |
| DOI: | 10.1016/0167-5273(90)90157-z |
| Popis: | The purpose of this study was to evaluate the effects of myocardial ischemia on the development of collateral circulation. Thirteen conscious dogs were instrumented for serial measurements of subendocardial segment length in the area perfused by the left circumflex coronary artery, left circumflex coronary artery flow and left ventricular pressure. In 6 dogs (group A), 1 min left circumflex coronary artery occlusions were carried out at 30 min intervals. When the 442nd 1 min left circumflex coronary artery occlusion produced a reduction in segment shortening and a significant reactive hyperemia, the occlusion time was increased to 2 min. In the remaining 7 dogs (group B), 2 min left circumflex coronary artery occlusions were conducted hourly. In group A, following 451 ± 201 (SD) min of total occlusion time with the mixture of 1 and 2 min left circumflex coronary artery occlusions (43 ± 18 days) a left circumflex coronary artery occlusion produced no reduction in segment shortening and negligible reactive hyperemia. By contrast, in group B, 218 ± 99 min of total occlusion time (18 ± 8 days) was required to develop adequate collateral circulation. The relative contribution of the first and second 1 min of left circumflex coronary artery occlusion to the collateral development was mathematically evaluated. This analysis indicated that the second 1 min of left circumflex coronary artery occlusion is 4.43-fold more effective than the first 1 min of occlusion in terms of the collateral induction. We concluded that severe myocardial ischemia plays an important role in the development of collateral circulation. |
| Databáze: | OpenAIRE |
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