REGIONAL MYOCARDIAL FUNCTIONAL AND ELECTROPHYSIOLOGICAL ALTERATIONS AFTER BRIEF CORONARY-ARTERY OCCLUSION IN CONSCIOUS DOGS
REGIONAL MYOCARDIAL FUNCTIONAL AND ELECTROPHYSIOLOGICAL ALTERATIONS AFTER BRIEF CORONARY-ARTERY OCCLUSION IN CONSCIOUS DOGS
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DOI：
10.1172/jci108178
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发表时间：
1975-01-01
影响因子：
15.9
通讯作者：
VATNER, SF
中科院分区：
文献类型：
--
作者：
HEYNDRICKX, GR;MILLARD, RW;VATNER, SF
本文研究了清醒犬短暂局部心肌缺血后机械功能恢复的时间关系、心肌内电信号与冠脉流量的关系。通过测量左心室收缩压、舒张压、左心室压力变化率(dp/dt)和dp/dt/P来评价左心室整体功能，通过测量局部节段长度和收缩速度来评价局部左心室功能。在左冠状动脉前降支或回旋支上植入液压封堵器，分别在不同的日子充气5分钟和15分钟。闭塞5分钟后，整体左心功能短暂下降，但就在闭塞解除前，整体功能几乎恢复到对照状态。此时，缺血区的局部功能仍被压低到收缩时无短缩或反常运动的程度，并与功能测量部位显著的ST段抬高(+10+/-2.2 mV)有关。结扎解除再灌流后，1min内心肌内心电图恢复正常，反应性充血消退5~10min。与冠状动脉血流和心电图迅速恢复到阻断前水平相反，局部机械功能持续抑制超过3h。冠脉阻塞15min导致缺血区更长时间(大于6h)的功能紊乱。因此，短暂的冠脉闭塞会导致局部心肌功能的长期损害，这种损害不能通过心电图和冠脉流量的快速恢复来预测。这些观察表明，冠状动脉血流的短暂中断要么导致局部缺血时间延长，要么由缺血引起的机械改变远远超过氧债的偿还。
The time relationship for recovery of mechanical function, the intramyocardial electrogram and coronary flow after brief periods of regional myocardial ischemia, was studied in conscious dogs. Total left vemtricular (LV) function was assessed with measurements of LV systolic and diastolic pressures, rate of change of LV pressure (dP/dt), and dP/dt/P. Regional LV function was assessed with measurements of regional segment length and velocity of shortening. An implanted hydraulic occluder on either the left anterior descending or circumflex coronary artery was inflated for 5- and 15-min periods on separate days. A 5-min occlusion depressed overall LV function transiently, but just before release of occlusion overall function had nearly returned to control. At this time regional function in the ischemic zone was still depressed to the point of absent shorteining or paradoxical motion during systole and was associated with marked ST segment elevation (+ 10 +/- 2.2 mV) at the site where function was measured. With release of occlusion and reperfusion the intramyocardial electrogram returned to normal within 1 min, and reactive hyperemia subsided by 5-10 min. In contrast to the rapid return to preocclusion levels for coronary flow and the electrogram, regional mechanical function remained depressed for over 3 h. A 15-min coronary occlusion resulted in an even more prolonged (greater than 6 h) derangement of function in the ischemic zone. Thus, brief periods of coronary occlusion result in prolonged impairement of regional myocardial function which could not have been predicted from the rapid return of the electrogram and coronary flow. These observations indicate that brief interruptions of coronary flow result either in a prolonged period of local ischemia or that alterations of mechanical induced by ischemia far outlast the repayment of the oxygen debt.