开胸前后左室外膜的心表电图

SURFACE ELECTROCARDIOGRAM OF LEFT VENTRICULAR EPICARDIUM BEFORE AND AFTER THORACOTOMY

用接触电极经胸壁穿刺在心包壁层记录家兔、豚鼠和犬左心室外膜的心表电图（SEG），同反映左心室面体表心电图进行对比研究的结果表明，在闭胸条件下左心室外膜的SEG与同步记录的反映左心室面体表ECG的各波方向和产生机理是一致的．开胸后SEG的QRS时限延长、ST段抬高或压低和T波倒置是由于心外股温度降低、心肌供血不足所致心肌冲动传导缓慢和其极反向所致．在缺血缺氧和药物等因素对心脏电活动影响的研究中，SEG是一个比ECG更为灵敏的电生理指标。

Surface electrocardiogram (SEG) of the left ventricular epicardium was recorded by puncturing an electrode into mediastinum and placing it on pedcardium in dogs.rabbits, and guinea pigs. Some parameters of SEG recoded before and after thoracotomy were compared and some fac-tors which affected SEG were also investigated in the article. The results indicated that all waves of SEG recored from the left ventricular epicardium and their producing mechanisms were similar to ECG reflecting the left ventricle in closed-chest state. The slow impulse transmission and abnormal tepolar ization in the myocardium caused by temperatute reduction and ischemia of the epicardium resulted in the elongation of the ventricular depolarization time, ST segment elevation or depression and T wave inversion. SEG was a more sensitive electrophysiological index in the study of the effects of ischemia or drugs on the electrical activity of the heart than ECG.