Näslund U, Häggmark S, Johansson G, Reiz S
University Hospital, Umeå, Sweden.
Cardiovasc Res. 1993 Feb;27(2):327-33. doi: 10.1093/cvr/27.2.327.
The aim was to investigate QRS vector changes during the first 30 min of coronary occlusion or the early phase of reperfusion with special reference to location and size of myocardium at risk.
24 h experiments were performed in closed chest anaesthetised pigs. QRS vectors were studied by computerised vectorcardiography via Frank leads. Occlusion of the left anterior descending coronary artery followed by reperfusion was induced in 23 pigs and a sustained occlusion in 20 pigs: left anterior descending coronary artery in seven, right coronary artery in eight, and left circumflex coronary artery in five. Myocardium at risk was measured in postmortem autoradiograms. Eight animals were excluded.
Four minutes after occlusion, QRS(mean) deviated towards the ischaemic region in 34/35 animals and returned thereafter at varying speeds. In half of the reperfused animals, deviation of QRS vectors towards the ischaemic territory was also observed during the first minutes of reperfusion. A paradoxical increase in QRS vector changes, "reperfusion peak", was recorded during the initial minutes of reperfusion in 12/19 animals. Maximum spatial QRS vector magnitude increased in all right coronary or left circumflex coronary occlusion animals compared to 6/25 in left anterior descending coronary occlusion animals. QRS vector difference, change in spatial QRS vector angle, and maximum change in QRS azimuth 4 min after occlusion correlated significantly with extent of myocardium at risk.
Marked directional and quantitative QRS vector changes, with significant relation to size and location of myocardium at risk, were recorded during the initial minutes of ischaemia. The transient increase in QRS vector changes during the first minutes of reperfusion deserves further exploration as a new indicator of reperfusion.
旨在研究冠状动脉闭塞最初30分钟或再灌注早期QRS向量的变化，特别关注危险心肌的位置和大小。
在闭胸麻醉猪身上进行24小时实验。通过Frank导联经计算机向量心电图研究QRS向量。23只猪诱导左前降支冠状动脉闭塞后再灌注，20只猪持续闭塞：左前降支冠状动脉7只，右冠状动脉8只，左旋支冠状动脉5只。在死后放射自显影片上测量危险心肌。排除8只动物。
闭塞4分钟后，34/35只动物的QRS（均值）偏向缺血区，此后以不同速度恢复。在一半再灌注动物中，再灌注最初几分钟也观察到QRS向量偏向缺血区。12/19只动物在再灌注最初几分钟记录到QRS向量变化的矛盾性增加，即“再灌注峰值”。与左前降支冠状动脉闭塞动物中的6/25相比，所有右冠状动脉或左旋支冠状动脉闭塞动物的最大空间QRS向量幅度增加。闭塞后4分钟的QRS向量差值、空间QRS向量角度变化和QRS方位最大变化与危险心肌范围显著相关。
在缺血最初几分钟记录到明显的方向性和定量性QRS向量变化，与危险心肌的大小和位置显著相关。再灌注最初几分钟QRS向量变化的短暂增加作为再灌注的新指标值得进一步探索。
