Establishment of a canine model of cardiac memory using endocardial pacing via internal jugular vein.
BACKGROUND
Development of experimental animal models has played an important role in understanding the mechanisms of cardiac memory. The purpose of this study was to evaluate a new canine model of cardiac memory using endocardial ventricular pacing via internal jugular vein.


METHODS
Twelve Beagle dogs underwent placement of a permanent ventricular pacemaker mimicking the use of pacemakers in humans and induction of cardiac memory by endocardial ventricular pacing.


RESULTS
Cardiac memory was achieved in 11 of 12 attempts overall. Procedural mortality due to cardiac tamponade (n = 1) occurred in the first attempt. The T-wave memory persisted for 96 +/- 17 minutes and 31 +/- 6 days in the short-term and long-term cardiac memory groups, respectively. There were no significant differences in the heart rate, blood pressure and echocardiographic parameters in the animals between before and after ventricular pacing in the short-term and long-term cardiac memory groups. No significant pathologic changes with the light microscopy were found in the present study in all dogs.


CONCLUSIONS
The model does require surgery but is not as invasive as an open-chest model. This canine model can serve as a useful tool for studying mechanisms of cardiac memory.
Yue-Chun
Li
L
Department of Cardiology, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang 325000, China. liyuechun1980@sina.com
Li-Sha
Ge
G
Xue-Qiang
Guang
G
Peng
Chen
C
Lian-Pin
Wu
W
Peng-Lin
Yang
Y
Ji-Fei
Tang
T
Jia-Feng
Lin
L
D000818:Animals; D002304:Cardiac Pacing, Artificial / Q000379:methods; D002305:Cardiac Tamponade / Q000209:etiology*; D002309:Cardiology; D002318:Cardiovascular Diseases / Q000628:therapy; D004285:Dogs; D004562:Electrocardiography; D004699:Endocardium / Q000473:pathology / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006801:Humans; D007601:Jugular Veins / Q000473:pathology / Q000601:surgery*; D023421:Models, Animal; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data; D011183:Postoperative Complications