Näslund U, Häggmark S, Johansson G, Reiz S
Department of Medicine, University Hospital, Umeå, Sweden.
Cardiovasc Res. 1993 Dec;27(12):2170-8. doi: 10.1093/cvr/27.12.2170.
The aim was to investigate whether continuous computerized vectorcardiographic monitoring of absolute spatial ST vector magnitude (ST-VM) and spatial ST change vector magnitude (STC-VM) during coronary occlusion could be used to estimate the size of myocardium at risk; and also to test whether reperfusion could be distinguished from sustained occlusion by continuous monitoring of ST vector alterations.
Computerised vectorcardiographic monitoring via Frank leads was applied in a closed chest occlusion-reperfusion pig model. Coronary occlusion over 24 h was produced in 20 animals by injecting a 2 mm ball into the left anterior descending coronary artery (n = 7), the right coronary artery (n = 8), and the left circumflex coronary artery (n = 5). Another 31 pigs were reperfused by retraction of the ball after 30 (n = 10), 60 (n = 15), or 90 (n = 6) min of left anterior descending artery occlusion. The extent of the myocardium at risk was measured by autoradiography.
Seven animals were excluded. Irrespective of occluded coronary artery the relative parameters STC-VM over the first 30 min of occlusion correlated closely with area at risk, that is, the mean STC-VM between 10 and 30 min of occlusion (r = 0.78 p < 0.001). The absolute parameter ST vector magnitude (ST-VM) did not reflect ischaemia in 16/44 animals and did not correlate significantly with area at risk. The weight of myocardium at risk (MAR) was predictable from STC-VM: MAR weight (measured) = 0.97 x MAR weight (predicted) + 0.26 (g), r = 0.81, p < 0.001. STC-VM decline rate, time to STC-VM plateau, and cumulated sum plots of STC-VM were all able to distinguish reliably between reperfused animals and those with permanent occlusion. A paradoxical increase in STC-VM - "reperfusion peak" - was detected in 17/31 (55%) of the animals. This phenomenon was related to large amount of myocardium at risk or to a long occlusion time.
Dynamic vectorcardiographic ST monitoring provides adequate estimation of myocardium at risk and enables detection of reperfusion in experimental myocardial ischaemia.
研究在冠状动脉闭塞期间，连续计算机化向量心电图监测绝对空间ST向量幅值（ST-VM）和空间ST变化向量幅值（STC-VM）是否可用于估计危险心肌的大小；并通过连续监测ST向量改变来测试能否区分再灌注和持续闭塞。
通过Frank导联进行计算机化向量心电图监测应用于闭胸式闭塞-再灌注猪模型。通过向20只动物的左前降支冠状动脉（n = 7）、右冠状动脉（n = 8）和左旋支冠状动脉（n = 5）注射一个2毫米的球囊，造成24小时的冠状动脉闭塞。另外31只猪在左前降支动脉闭塞30分钟（n = 10）、60分钟（n = 15）或90分钟（n = 6）后通过回撤球囊实现再灌注。通过放射自显影测量危险心肌的范围。
排除7只动物。无论闭塞的冠状动脉如何，闭塞最初30分钟内的相对参数STC-VM与危险区域密切相关，即闭塞10至30分钟之间的平均STC-VM（r = 0.78，p < 0.001）。绝对参数ST向量幅值（ST-VM）在16/44只动物中未反映缺血情况，且与危险区域无显著相关性。危险心肌重量（MAR）可根据STC-VM预测：MAR重量（测量值）= 0.97×MAR重量（预测值）+ 0.26（克），r = 0.81，p < 0.001。STC-VM下降率、达到STC-VM平台期的时间以及STC-VM的累积和图均能够可靠地区分再灌注动物和永久性闭塞动物。在17/31（55%）的动物中检测到STC-VM的反常增加——“再灌注峰值”。这种现象与大量危险心肌或长时间闭塞有关。
动态向量心电图ST监测可对危险心肌进行充分估计，并能够在实验性心肌缺血中检测到再灌注。
