Non-ischemic myocardial infarction in a swine model

Objective To observe the development of non-ischemic myocardial infarction.Methods Twelve Chinese mini-pigs,weishing 18-20 kg,were randomly divided into the experimental group and control group(n=6).LAD was ligated at site of(25.06±2.50)ml/min in experimental group and tunica adventitia was dissected free only in control group respectively.All animals underwent serial hemodvnamie studies of apical and bottom of left ventricle during operation.Four weeks after LAD ligation left ventricle myocardium WaS divided into 17 segments.and sections from each myocardium segment were fixed in 5% buffered formalin.paraffin embedded,sectioned at 3 to 4 m,and stained with hematoxylin and eosin.PTAH and Picrosifins Red for pathologic observations.Results In the experimental group,there were significant increases in left ventricle systolic pressure[(264.05±49.34)vs(168.35±31.74)mm Hg(1 mm Hg)=0.133 kPa)],mean.blood pressure[(128.65±33.68)vs(82.86±14.45)mm Hg]and development pressure[(255.09±103.18)vs(178.70±31.70)mm Hg]in the bottom as,conpared with those in the apical of left ventricle 4 weeks after LAD ligation.Analysis of the histologic sections from the 17 segments of LV,including the infarct,border zone and the remote demonstrated fibrosis consistent with healed infarction and invjable tissues occurred in all the 17 segments of myocardium.Conclusion Infracted myocardium extends to involve 17 segments of myocardium of the whole left ventricle as left ventricle remodeling after LAD ligation. Key words: Acute myocardial infarction;  Model,animal