Sadick N, McHale P A, Dube G P, Greenfield J C
Department of Medicine, Duke University Medical Center, Durham.
Basic Res Cardiol. 1987 Nov-Dec;82(6):585-95. doi: 10.1007/BF01907229.
The aim of this study was to determine whether or not coronary vasoconstriction occurs in response to a transient increase in coronary perfusion pressure. Eleven awake dogs with formalin-induced heart block, chronically instrumented with aortic and left ventricular catheters and left circumflex coronary and aortic electromagnetic flowprobes, were studied at a paced heart rate of 60 beats/min. A transient increase in aortic diastolic pressure of 17.3 +/- 1.5% for 330 +/- 20 ms and of 33.6 +/- 2.2% for 520 +/- 20 ms, via the inflation of an intra-aortic balloon, resulted in an increase in diastolic coronary vascular resistance index in the first response beat of 6 +/- 1% and 11 +/- 1%, respectively. An identical increase in diastolic coronary flow produced by the omission of a single paced beat resulted in no significant change in diastolic coronary vascular resistance index in the first response beat. Thus, the increase in diastolic coronary vascular resistance index following diastolic pressure augmentation is related to the increase in aortic diastolic pressure and not to the increase in diastolic coronary flow. These data are consistent with that of a brief myogenic response.
本研究的目的是确定冠状动脉灌注压短暂升高时是否会发生冠状动脉血管收缩。对11只因福尔马林诱导心脏传导阻滞而清醒的犬进行研究，这些犬长期植入主动脉和左心室导管以及左旋支冠状动脉和主动脉电磁血流探头，在心率60次/分钟的起搏状态下进行观察。通过主动脉内气囊充气，使主动脉舒张压短暂升高，在330±20毫秒内升高17.3±1.5%，在520±20毫秒内升高33.6±2.2%，结果在第一个反应搏动中，舒张期冠状动脉血管阻力指数分别增加6±1%和11±1%。因遗漏一次起搏搏动而使舒张期冠状动脉血流量同样增加，在第一个反应搏动中，舒张期冠状动脉血管阻力指数无显著变化。因此，舒张压升高后舒张期冠状动脉血管阻力指数的增加与主动脉舒张压的升高有关，而与舒张期冠状动脉血流量的增加无关。这些数据与短暂的肌源性反应的数据一致。
