猫冠状动脉缺血与再灌注对房室传导的影响

急性下壁心肌梗塞常引起房室传导功能障碍,然而这种障碍与心肌缺血的内在联系并不很清楚,本实验在去植物性神经传出纤维的猫上进行,通过模板匹配方法从Ｈｉｓ束电图检测Ａ,Ｈ,Ｖ波并测量两心房间期（ＡＡ）,心房波与Ｈｉｓ波间期（ＡＨ）,Ｈｉｓ波与心室波间期（ＨＶ）和心房波与心室波间期（ＡＶ）。结果如下：结扎右冠状动脉后,２０只动物的ＡＨ间期１４只出现增加（Ａ组）６只未出现增加（Ｂ组）对Ｂ组进行快速心房起博和

Atrioventricular conduction changes in acute ischemic and reperfused coronary artery of cats

Acute inferior wall infarction is freguently complicated by conduction disturbance, but the relationship between ischemia and atrioventricular (AV) conduction disturbance is not well understood. The present experiments were made on cats with heart efferent completely denervated.A,H and V waves were picked up by a template maching algorithm from His bundle electrogram, AA interval (cardiac cycle length), AH interval (AV conduction time), HV and AV intervals were measured . Of 20 cats, 14 showed prolongation of AH interval (Group A), while not in 6 cats (Group B) after ligation of right coronary artery. A fast pacing of right atrium (AA interval=267 ms) was produced in Group B and AH interval was also prolonged after ligation of the artery. By multiple step pacing, the curve of AV nodal function shifted to the right, AH intrval which induced AV nodal block was prolonged after ischemia. After reperfusion, AH interval was shortened both in Group A and B. The above results show that myocardial ischemia may cause abnormality of AV conduction and accommodation function. The abnormality appears to be a potential danger which will induce AV conducton block during tachycardia.