Ino-Oka E, Kitaoka S, Shimizu Y, Kyono H, Maehara K, Maruyama Y, Ashikawa K, Isoyama S, Tamaki K, Satoh S
Tohoku J Exp Med. 1984 Sep;144(1):43-55. doi: 10.1620/tjem.144.43.
The correlation between the ST segment displacement and coronary blood flow in various hemodynamic conditions was studied. Five isolated, isovolumic contracting canine hearts were used. The left main and the right and left circumflex (LCx) coronary arteries were cannulated and perfused with support dog's arterial blood. Four pairs of Ag-AgCl ECG electrodes were attached to the epicardium and subendocardium in the LCx perfused area. Heart rate and left ventricular end-diastolic pressure (LVEDP) were controlled by means of right atrial electrical pacing and infusion or withdrawal of arterial blood into the left ventricle, respectively. LCx flow was reduced by 75, 50, 25% of the control level under the condition of 200 beats/min of heart rate and 20 mmHg or 5 mmHg of LVEDP, and ECGs were recorded. The ST segment elevation was observed in epi- and subendocardial lead ECGs when LCx flow was reduced from 110 +/- 27.5 ml/min/100 g to 72 +/- 3 ml/min/100 g under the condition of normal LVEDP (5 mmHg) and a high heart rate (200 beats/min), whereas the same degree of reduction in LCx flow under the condition of high LVEDP (20 mmHg) and high heart rate (200 beats/min) resulted in an epicardial ST segment depression associated with marked subendocardial ST segment elevation. The results suggest that the coronary flow reduction with a higher LVEDP will induce subendocardial ischemia, whereas the same degree flow reduction with a normal LVEDP induce transmural ischemia.
研究了在各种血流动力学条件下ST段位移与冠状动脉血流之间的相关性。使用了5个离体的、等容收缩的犬心脏。将左主干、右冠状动脉和左旋支（LCx）冠状动脉插管，并用供体犬的动脉血进行灌注。在LCx灌注区域的心外膜和心内膜下连接了四对Ag-AgCl心电图电极。分别通过右心房电起搏以及向左心室输注或抽取动脉血来控制心率和左心室舒张末期压力（LVEDP）。在心率为200次/分钟且LVEDP为20 mmHg或5 mmHg的条件下，将LCx血流减少至对照水平的75%、50%、25%，并记录心电图。当在正常LVEDP（5 mmHg）和高心率（200次/分钟）条件下，LCx血流从110±27.5 ml/min/100 g降至72±3 ml/min/100 g时，在心外膜和心内膜下导联心电图中观察到ST段抬高；而在高LVEDP（20 mmHg）和高心率（200次/分钟）条件下，相同程度的LCx血流减少则导致心外膜ST段压低并伴有明显的心内膜下ST段抬高。结果表明，较高LVEDP时冠状动脉血流减少会诱发心内膜下缺血，而正常LVEDP时相同程度的血流减少会诱发透壁性缺血。
