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

Abstract

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. Key words: Cardiac arrest; Cardiopulmonary resuscitation; Epicardium; Electrical stimulation;  Animal models