犬急性心肌梗塞后心外膜电图碎裂电位和室性心律失常的关系

Epicardial Fractionated Potentials and Ventricular Arrhythmias in the Acute Myocardial Infarction in Dog

10只急性心肌梗塞后2～6天的犬中,4只在窦性心律时缺血区心外膜电图上出现迟发的碎裂电活动。碎裂电位的特点为:同一部位的碎裂电位可随时间延长而有所变化,可出现在梗塞区或缺血边缘区。可以引起室性早搏或隐匿性地激动全心室。有碎裂电位的犬心经心脏程序电刺激均可诱发出室性心律失常;并且心肌梗塞面积显著大于无碎裂电位的其它犬心。提示局部心外膜电图中的碎裂电位是心室内存在潜在折返环路的重要标志。

Late fractionated potentials (LFP) of the epicardial electrograms were found by local epicardial mapping technique in the 4 hearts 2-6 days after the occlusion of anterior descending coronary artery in 10 dogs. The characteristics of LFP were : They all occurred 43 hours after acute myocardial infarction; The fractionated potentials of the same epicardial site could change with time; LFP could occur on the severe ische-mic zone or border zone; LFP could induce ventricular premature beats or concealed activation of whole ventricles spontaneously; Cardiac programmed electrical stimulation could induce ventricular arrhythmias and infarction size were significantly larger in all 4 dogs with LFP than of others. It was suggested that LFP has positive correlation with ventricular arrhythmia occurrence and is the sign of the existence of ventricular reentrant circuit in the ischemic area after mycardial infarction.