Jensen S M, Johansson G, Osterman G, Reiz S, Näslund U
Department of Internal Medicine, University Hospital, UMEA, Sweden.
Coron Artery Dis. 1994 Jun;5(6):507-14.
With new interventions minimizing ischemic myocardial injury, accurate and reliable techniques for the detection and continuous monitoring of myocardial ischemia are essential. We compared two techniques used for the detection of myocardial ischemia during coronary angioplasty: on-line computerized vectorcardiographic (cVCG) monitoring and the standard electrocardiography (ECG) leads or the complete 12-lead ECG.
Thirty patients scheduled for routine angioplasty were included in the study. cVCG was recorded continuously. The electrodes were placed according to the lead system described by Frank and connected to a computerized system for on-line vectorcardiography. A 12-lead ECG was recorded simultaneously. The absolute variable spatial ST vector magnitude (ST-VM) and the relative variable spatial ST change vector magnitude (STC-VM) were calculated and compared with the standard 12-lead ECG for the detection of ischemia.
The sum of deviation in ST segment in all 12 standard ECG leads correlated closely with STC-VM, irrespective of which artery was occluded. STC-VM indicated ischemia during the first balloon inflation in 87% of the patients and demonstrated ischemia in more patients than the standard 12-lead ECG. Myocardial ischemia was not demonstrated by ST-VM in five out of 26 patients with ischemia according to STC-VM. In these cases, mainly directional vector changes and fewer changes in magnitude were observed.
Compared with 12-lead ECG, on-line cVCG is a more sensitive method of detecting myocardial ischemia during coronary angioplasty and the reading is easier and faster. Our results support STC-VM > or = 0.050 mV as the criterion for ischemia during angioplasty; ST-VM should be applied together with STC-VM.
随着新的干预措施将缺血性心肌损伤降至最低，用于检测和持续监测心肌缺血的准确可靠技术至关重要。我们比较了两种用于冠状动脉血管成形术期间检测心肌缺血的技术：在线计算机化向量心电图（cVCG）监测和标准心电图（ECG）导联或完整的12导联心电图。
30例计划进行常规血管成形术的患者纳入本研究。连续记录cVCG。电极根据Frank描述的导联系统放置，并连接到用于在线向量心电图的计算机系统。同时记录12导联心电图。计算绝对可变空间ST向量幅度（ST-VM）和相对可变空间ST变化向量幅度（STC-VM），并与标准12导联心电图比较以检测缺血。
无论阻塞哪条动脉，所有12个标准心电图导联中ST段偏差之和与STC-VM密切相关。STC-VM在87%的患者首次球囊扩张时提示缺血，且显示缺血的患者比标准12导联心电图更多。根据STC-VM，26例缺血患者中有5例ST-VM未显示心肌缺血。在这些病例中，主要观察到方向向量变化，幅度变化较少。
与12导联心电图相比，在线cVCG是冠状动脉血管成形术期间检测心肌缺血更敏感的方法，且读数更容易、更快。我们的结果支持将STC-VM≥0.050 mV作为血管成形术期间缺血的标准；ST-VM应与STC-VM一起应用。
