Objective    To establish a swine model of chronic myocardial ischemia for medical imaging research.     Methods    Ten pigs (20 to 26 kg) were sedated with an intramuscular injection of telazol (5 mg/kg). Thoracotomy was performed through the fourth left intercostal space. The pericardium was opened and an ameroid constrictor was placed around the proximal left circumflex artery (LCX) just distal to the main stem of the left coronary artery matching the size of the vessel. Animals received medical imaging examinations

including coronary angiography

cardiac MRI

echocardiography and cardiac SPECT once a week within 5 to 6 weeks after the surgery. The degree of coronary artery stenosis was evaluated according to the results of coronary angiography.     Results    Of the 10 pigs

2 died at the early stage after surgery

and the left 8 were successfully induced to have chronic myocardial ischemia. The mild stenosis of LCX was found in 1 week after surgery

and the longer after surgery

the more serious stenosis of LCX was found. Ninety percent stenosis of LCX was found in 1

4 and 3 pigs respectively in 3

5 and 6 weeks after surgery. Thin lateral and posterior wall of left ventricle was found in plain MRI

which showing marked enhancement in delayed MRI perfusion scan. Echocardiography and SPECT showed motion weakness

function reduction and perfusion decrease or defects of ischemic segments of left ventricle.     Conclusion    The animal model of chronic myocardial ischemia can be successfully established with ameroid constrictor in pigs

which is an ideal model for medical imaging research.