| Autor: |
Di Palma, Joseph R., McMichael, Robert F. |
| Předmět: |
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| Zdroj: |
Angiology; Nov1961, Vol. 12 Issue 11, p564-573, 10p |
| Abstrakt: |
A method has been investigated which aims to establishment of, and endpoint to, the ischemia changes induced by temporary artery ligation to reflect the state of coronary blood circulation. It has been found that a critically discernible change in a directly recorded unipolar action potential may be defined when the endpoint of ischemia change, cessation of myocardial contractility is reached. On the basis of this, the range of ischemia time and recovery time has been established for normal control animals. The range in 24 dogs was wide, ischemia time 101 see. SEm ± 8.4 sec., recovery time 115 sec. SEm ± 10.6 sec. This wide variation was found to be related to the differences in blood pressure and pulse in the animals. Correction for this factor, by a rough index of heart work (blood pressure X pulse) gave figures for the same animals of ischemia index 7.6 SEm ± 0.3 × 105 anti recovery index 8.9 SEm ± 0.7 × 105 Studies with sympathomimetic amines such as norepinephrine showed that ischemia index was favorably affected only over a narrow range of dose. On the other hand, drugs as hexamethonium adversely influenced the ischemia index. Sodium nitrite did not disturb the ischemia or recovery indices. The method shows promise for further investigation of coronary blood flow in relationship to the demands of the myocardium for blind and for the elucidation of drug action. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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