经皮电刺激心外膜建立大鼠心搏骤停模型

目的 通过经皮电刺激心外膜的方法建立大鼠心搏骤停(cardiac arrest,CA)模型.方法 实验地点在中山大学卫生部辅助循环重点实验室,选择20只雄性Sprague-Dawley大鼠,两根经皮刺人心外膜的细针作为电极与刺激器相连,持续刺激3 min而诱发CA,无干预观察6 min后进行心肺复苏(cardiopulmonary resuscitation,CPR).结果 刺激电流强度1 mA时诱发CA成功12只,2 mA时全部诱发成功.从有效电刺激开始到成功诱发CA的时间为(5.10±2.81)s.电刺激结束时表现为室颤的18只,无脉性电活动2只.CPR用时(207.4±148.8)s,自主循环恢复率为20/20,CA后4 h内的死亡率为5/25,72 h时存活率为10/20.有2只大鼠分别并发轻微肌肉收缩和轻度肺叶损伤.结论 经皮电刺激心外膜诱发大鼠CA具有模型稳定、操作简单、所需刺激电流强度小、并发症少的优点.

Rat models of cardiac arrest induced by transcutaneous electrical stimulation on the epicardium

Objective To establish a new model of cardiac arrest (CA) in rats by transcutaneous electrical epicardium stimulation. Method Two acupuncture needles connected to the anode and cathode of a stimulator were transcutaneously inserted into the epicardium as electrodes. The stimulating current was steered to the epicardium and the stimulation was maintained for 3 minutes to induce CA. Cardiopulmonary resuscitation (CPR) was performed at 6 minutes after a period of nonintervention. Results The success rate of induction was 12/20 at the current intensity of 1 mA; and reached 20/20 when the current intensity was increased to 2 mA. The average time from the electrical stimulation to CA induction was (5. 10 ± 2. 81) seconds. When the electrical stimulation stopped, 18/20 rats had ventricular fibrillation and 2/20 rats had pulseless electrical activity. CPR was performed for averagely 207.4 ( ± 148.8) seconds. The restoration of spontaneous circulation was 20/20. The death rate within 4 hours after CA was 5/20, and the 72-hour survival rate was 10/20. There were only two cases of complications, a minor muscle contraction and a minor lung lobe injury. Conclusions The model of CA in rats induced by transcutaneous electrical epicardium stimulation is a stable model that requires low-intensity current and has fewer complications.