| Autor: |
Fujita, Masatoshi, Mikuniya, Atsushi, McKown, Daniel P., McKown, Michael D., Franklin, Dean |
| Zdroj: |
Heart and Vessels; September 1987, Vol. 3 Issue: 3 p122-128, 7p |
| Abstrakt: |
Summary Studies were performed on seven conscious dogs chronically instrumented for measurement of subendocardial segment length in the central area perfused by the left circumflex coronary artery (LCCA) and left anterior descending coronary artery, LCCA flow, and left ventricular pressure. We occluded the LCCA for 2 min using an externally inflatable pneumatic occluder placed around the proximal LCCA. Two-minute LCCA occlusions were repeated hourly for 8 h, 5 days/week. The first LCCA occlusion decreased the ejection phase shortening in the ischemic area from 22.2%±2.5% (SEM) to 3.1%±0.7% (P<0.001). Concomitantly, heart rate increased from a resting rate of 76±4 to 117±6 beats/min (P<0.001) after 2 min of LCCA occlusion, and ejection phase shortening in the nonischemic area decreased from 25.5%±1.3% to 21.6%±1.1% (P<0.001) despite increases in end-diastolic segment length (15.31±1.46 mm to 15.69±1.52 mm,P<0.01). These changes in non-ischemic segment shortening and heart rate during LCCA occlusion were attenuated progressively with improvement in the regional myocardial function at jeopardy due to the development of collateral circulation, and a significant (P<0.001) correlation between both the reduced nonischemic segment shortening and the increased heart rate with the degree of dysfunction in the ischemic region was obtained by linear regression analysis with Fisher's Z transformation. |
| Databáze: |
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