Background:Myocardial perfusion grade (MPG) is an accepted method of evaluating myocardial perfusion.However,it does not take into the account,the extent of the perfusion.We hypothesized that myocardial blush area times MPG (total blush) would be more accurate than simple MPG,and yield better prognostic information.Methods:About 34 patients were recruited after they had consented to both coronary angiography (CAG) and single photon emission computed tomography (SPECT),and divided into two groups.A special dedicated computer was employed to calculate the total blush.The CAG was performed as a conventional way.Scintigraphic technetium 99m methoxyisobutyl-isonitrile rest and stress images were evaluated quantitatively.The comparison was made between stenosis versus chronic total occlusion (CTO),MPG 1,2 versus MPG 3,percutaneous intervention (PCI) successful versus failure.A correlation was made between ejection fraction (EF) and myocardial perfusion by MPG,total blush,SPECT,and syntax score.Results:The perfusion indices of total blush,summed difference score (SDS) and syntax score were insignificant between the two groups (P ＞ 0.05).However,the left ventricular end diastolic volume was significantly larger in CTO (P ＜ 0.05).The patients with stenosis had better MPG than with CTO (P ＜ 0.05).The increased MPG was associated with increased total blush,higher syntax score,and EF (P ＜ 0.05).Successful PCI resulted in better perfusion indicated by increased total blush,and MPG (P ＜ 0.05) but successful PCI did not change syntax score,EF and SDS significantly.Multivariate linear analysis with EF as the dependent factor and syntax score,SDS,total blush,blush area,and MPG as the independent factors showed a significantly higher degree of correlation (R =0.87,P ＜ 0.05).Conclusion:After PCI the total blush and EF improved significantly indicating its potential application in the future.