Abboud S, Smith J M, Shargorodsky B, Laniado S, Sadeh D, Cohen R J
Raymond and Beverly Sackler, Faculty of Exact Sciences, School of Physics and Astronomy, Tel Aviv University, Israel.
Pacing Clin Electrophysiol. 1989 Apr;12(4 Pt 1):574-81. doi: 10.1111/j.1540-8159.1989.tb02703.x.
The ability to detect cardiac ischemia in dogs was studied using high frequency electrocardiography and signal averaging technique. Ischemia was induced via a balloon occluding cuff placed around the left anterior descending coronary artery. Three surface orthogonal bipolar leads (X, Y, and Z) were recorded prior to inflation of the occluding cuff. The cuff was then inflated, causing a complete occlusion of the coronary artery. The surface electrocardiogram was recorded before and during ligation and during reperfusion. The recorded waveforms were divided into sequential 10-15 second segments representing different stages of the ischemic state and were aligned using cross-correlation scheme, averaged and band pass filtered between 150-250 Hz. Analysis of the filtered high frequency QRS complexes revealed that coronary ligation was accompanied by changes in waveform morphology including the appearance of zones of reduced amplitude. In seven out of ten experiments reduced amplitude zones were absent before the ligation, present during the occlusion and absent following reperfusion. In two experiments, reduced amplitude zones that were present prior to ligation became wider during occlusion. In one experiment no reduced amplitude zone was present during any stage of the experiment. Such zones may represent slow conduction in regions of the heart rendered ischemia during coronary ligation. Therefore, the morphology of the high frequency QRS complex, as determined by analysis of the signal averaged electrocardiogram, may provide useful information regarding the presence of myocardial ischemia.
利用高频心电图和信号平均技术研究了犬心脏缺血的检测能力。通过围绕左前降支冠状动脉放置的球囊阻塞袖带诱导缺血。在阻塞袖带充气前记录三个体表正交双极导联（X、Y和Z）。然后使袖带充气，导致冠状动脉完全阻塞。在结扎前、结扎期间和再灌注期间记录体表心电图。记录的波形被分成代表缺血状态不同阶段的连续10 - 15秒片段，并使用互相关方案进行对齐、平均，并在150 - 250 Hz之间进行带通滤波。对滤波后的高频QRS复合波的分析表明，冠状动脉结扎伴随着波形形态的变化，包括出现振幅降低区域。在十次实验中的七次中，结扎前无振幅降低区域，阻塞期间出现，再灌注后消失。在两次实验中，结扎前存在的振幅降低区域在阻塞期间变宽。在一次实验中，实验的任何阶段都没有出现振幅降低区域。这些区域可能代表冠状动脉结扎期间心脏缺血区域的缓慢传导。因此，通过对信号平均心电图的分析确定的高频QRS复合波的形态，可能提供有关心肌缺血存在的有用信息。
