Animal Model Of Chronic Myocardial Ischemia And Collateral Circulation Development

Animal Model of Chronic Myocardialischemia and Collateral CirculationDevelopmentAbstractObjective:Exercise training in patients with coronary artery disease was the major approach in rehabilitation. The efficacy was identified on the peripheral mechanism, the central effects of exercise training which could promote the collateral circulation was still in controversy partially because the animal model of chronic coronary stenosis and collateral circulation development had not been satisfactorily established. Our study was to develop an animal model of chronic coronary stenosis and formation of collateral circulation in swine.Methods:Ameroid constrictor was implanted around the left circumflex branch of coronary artery proximal to the first marginal branch after thoracotomy and pericardiectomy were performed in ten male swine. Selective coronary angiography, Echo-Doppler study and pathological examination were conducted pre and 3 weeks post surgery to evaluate the degree of stenosis, collaterals and myocardial function.Results:(1) Total occlusion and partial stenosis (>75%) were observed in 4 and 5 swine respectively. (2) Left anterior descendant branch of coronary artery was large and circuitous and a number of the collateral branches formed vascular net was seen in ischemial region. (3) Cardiac2systolic and diastolic dysfunction were found significantly.(4)The mild cardiac degeneration and interstitial space broadening in some myocardial cells were evident but no myocardial infarction formation in all subjects.Conclusion:(l)The modified Ameroid approach was applicable to make an animal model of chronic coronary stenosis, and the vascular stenosis or occlusion can be judged apparently. (2) The formation of collateral circulation with development of stenosis or occlusion in the swine can be observed obviously after implantation of Ameroid constrictor around the Left Circunflex Artery. This result evidented that the modified Ameroid constrictor method might create an important condition in research of cardiac exercise training and rehabilitation.