Myocardial oxygenation in dogs during partial and complete coronary artery occlusion.
Myocardial oxygenation in dogs during partial and complete coronary artery occlusion.
复制标题
狗冠状动脉部分和完全闭塞期间的心肌氧合。
DOI：
10.1161/01.res.73.3.458
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发表时间：
1993
影响因子：
20.1
通讯作者：
Piantadosi,CA
中科院分区：
文献类型：
--
作者：
Parsons,WJ;Rembert,JC;Bauman,RP;Duhaylongsod,FG;GreenfieldJr,JC;Piantadosi,CA
在冠状动脉部分和完全闭塞时，用近红外光谱评估局部心肌氧合。在8只开胸犬中，部分闭塞导致左冠状动脉前降支（LAD）血流减少约42%，组织氧储存（组织氧合血红蛋白加氧合肌红蛋白）减少约21%，线粒体细胞色素aa3的氧化水平没有变化。LAD血流量减少约81%，导致组织氧合血红蛋白+氧合肌红蛋白最低水平，脱氧血红蛋白+脱氧肌红蛋白最高水平，组织血容量下降，细胞色素aa3氧化水平下降约39%。这些变化与通过放射性标记微球测量的平均跨壁心肌血流量比缺血前基线减少约52%以及心肌耗氧量减少约41%相关。完全闭塞导致心肌血流量、耗氧量、组织血容量和细胞色素aa3氧化状态进一步降低，但也使组织氧储存增加到高于部分闭塞时的最低点。这些结果表明，在冠状动脉部分闭塞期间，氧气输送的减少增加了氧气的提取，以维持线粒体的氧气供应，但心肌血流量仅减少52%，就会产生最大的氧气提取和组织氧气储存的消耗。在完全闭塞期间，由于O2输送受限，组织血容量和O2提取可能减少，线粒体O2可用性进一步受到限制。
Regional myocardial oxygenation was assessed during partial and complete coronary artery occlusion using near infrared spectroscopy. In eight open-chest dogs, partial occlusions resulting in an approximately 42% decrease in left anterior descending coronary artery (LAD) blood flow produced an approximately 21% decrease in tissue O2 stores (tissue oxyhemoglobin plus oxymyoglobin) and no change in the oxidation level of mitochondrial cytochrome aa3. An approximately 81% reduction in LAD blood flow produced nadir levels of tissue oxyhemoglobin plus oxymyoglobin, maximal levels of deoxyhemoglobin plus deoxymyoglobin, a decline in tissue blood volume, and an approximately 39% decrease in cytochrome aa3 oxidation level. These changes were associated with an approximately 52% decrease from the preischemic baseline in mean transmural myocardial blood flow, measured by radiolabeled microspheres, and an approximately 41% decrease in myocardial O2 consumption. Complete occlusion resulted in further decreases in myocardial blood flow, O2 consumption, tissue blood volume, and cytochrome aa3 oxidation state but also produced increases in tissue O2 stores to above the nadir levels noted during partial occlusion. These results indicate that decreases in O2 delivery during partial coronary occlusion increase O2 extraction to sustain mitochondrial O2 availability, but as little as a 52% reduction in myocardial blood flow produces maximal O2 extraction and depletion of tissue O2 stores. Mitochondrial O2 availability is restricted further during complete occlusion because of limited O2 delivery and, possibly, decreases in tissue blood volume and O2 extraction.