Development of an ovine model of myocardial infarction.
BACKGROUND
We report experimental myocardial infarction by occluding coronary arteries in ovine models.


METHODS
Twelve ewes were included in the study. After the chest was opened by left lateral thoracotomy incision, the second diagonal branch of the left anterior descending coronary artery was ligated at a point approximately 40% distant from its base. Prophylactic anti-arrhythmics were given. Animals were mechanically ventilated during surgery and stayed in intensive care unit for 24 h postoperation. Experiments were then evaluated by echocardiographic, electrocardiographic, haemodynamic, serological and morphological investigations. Echocardiographic measurements were repeated after 2 months and animals were then killed for post-mortem cardiac examinations.


RESULTS
All animals survived the surgical procedure. Cyanotic discoloration and hypokinesia in the cardiac tissue in an area of (30 +/- 2) x (4 +/- 2) mm plus ST-segment elevations was detected immediately after vessel ligation. Moreover, there were pathological Q-waves 2 months later. Echocardiographic evaluations showed an average of 30% relative decrease in cardiac ejection fraction. Wall motion analysis showed anteroseptal hypokinesia and akinesia in all animals 1 day and 2 months after operation, respectively. Thin-walled infarcted areas with tissue fibrosis were evident in pathological investigations 2 months after surgery.


CONCLUSIONS
In conclusion, we developed a practical and safe method for producing myocardial infarction in large animal models.
Rabbani
Shahram
S
Research Department, Tehran Heart Center, Medical Sciences, University of Tehran, Tehran, Iran. shrabbani@gmail.com
Ahmadi
Hossein
H
Fayazzadeh
Ehsan
E
Sahebjam
Mohammad
M
Boroumand
Mohammad A
MA
Sotudeh
Maryam
M
Nassiri
Seyed Mahdi
SM
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D006348:Cardiac Surgical Procedures / Q000379:methods; D003331:Coronary Vessels / Q000601:surgery; D004195:Disease Models, Animal; D004452:Echocardiography; D004562:Electrocardiography; D006339:Heart Rate / Q000502:physiology; D008026:Ligation; D009203:Myocardial Infarction / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D012756:Sheep; D013318:Stroke Volume / Q000502:physiology