A simpler cardiac arrest model in the mouse.
OBJECTIVE
Delivering alternating currency (AC) to right ventricular endocardium to induce ventricular fibrillation (VF) in mice is complicated. We tried to validate whether transoesophageal AC stimulation could induce VF and how long AC stimulation had to be sustained to prevent the spontaneous cardioversion of VF in mice.


METHODS
A pacing electrode was inserted orally into the oesophagus and AC was delivered to esophagus through the pacing electrode to stimulate the heart and induce VF in 15 mice. The incidence of VF and time of AC stimulation were recorded 4min after onset of VF cardiopulmonary resuscitation (CPR) was started.


RESULTS
VF was induced by short AC stimulation in all 15 mice. With the prolongation of AC stimulation, the incidences of spontaneous cardioversion of VF decreased whereas the incidence of pulseless electrical activity (PEA) increased accordingly. Following the termination of prolonged AC stimulation, VF occurred only in 1 of 15 mice, but PEA in 14 of 15 mice. Before CPR 1 of 15 and 12 of 15 animals remained in VF and in PEA, respectively, while 2 of 15 animals developed into asystole. After CPR, 11 of 15 animals were successfully resuscitated.


CONCLUSIONS
VF can be induced by a short period of transoesophageal AC stimulation in mice. However, prolonged AC stimulation is prone to induce PEA other than VF. Nonetheless, the development of a mouse CA model in this manner is simpler and easier, which may have practical significance for facilitating experimental investigation on CA and CPR.
Chen
Meng-Hua
MH
Institute of Cardiovascular Diseases, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China. cmhnn@sina.com
Liu
Tang-Wei
TW
Xie
Lu
L
Song
Feng-Qing
FQ
He
Tao
T
Mo
Shu-Rong
SR
Zeng
Zhi-Yu
ZY
D000818:Animals; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004195:Disease Models, Animal; D004562:Electrocardiography; D005260:Female; D006323:Heart Arrest / Q000209:etiology / Q000628:therapy*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000150:complications / Q000503:physiopathology