The Study Of Correlation Between The Severity Of Coronary Artery Stenosis,left Ventricle Anatomy And Systolic Function Evaluated By MSCT

ObjectiveTo discuss correlation between Multi-slice spiral CT coronary artery angiography (MSCTCA) and Transthoracic echocardiography (TTE)in the quantitative evaluation of left ventricular function,and further to discuss relationship between the severity of coronary artery stenosis,left ventricle anatomy and global systolic function noninvasively evaluated by Multi-slice spiral CT.MethodsFrom December 2009 to November 2010,thirty patients among 200 suspicious coronary heart disease evaluated by MSCTCA simultaneously were examined by TTE ,which included 130 male cases and 70 females cases, aged range from 33 to 88 years old,mean age 58±23 years. Cardiac anatomy ang functional parameters of each patient were measured. The both examination time intervals by MSCTCA and TTE was less than 12 hours.Ten series of images were reconstructed at every 10% R-R interval by using the MSCTCA raw data set. From the reconstructed cardiac planes CT images (left ventricle short axis, long axis, and four-chamber view),the minimum systolic volumes and maximum diastolic volumes were determined by observing dynamic changes of left ventricular volume according to ECG. Usually,systolic phase in the 20% to 40% R-R interval, the diastolic phase in the 60% to 80% R-R interval. The contours of endocardium and epicardium diastolic and systolic end phases were outlined in the circulation cardiac functional software,and left ventricular outflow tract and papillary muscles were included in the blood pool.The left ventricular function parameters,such as end-diastolic volume (EDV), end systolic volume (ESV), and stroke volume (SV), ejection fraction (EF), left ventricular fraction shortening (FS) and cardiac mass (MM),were calculated by using Simpson's method. And each coronary artery stenosis was evaluated by the circulation or Inspace vessel analysis software.Echocardiography was performed independently using the instruments HP Sonos-5500 Color Doppler ultrasound diagnostic apparatus by two associate chief physician. The left ventricular function by M-mode Color Doppler was determined.Thirty patients underwent by the both checking modality were divided into two group,respectively MSCTCA and TTE. According to 17-segment modified AHA classification, the stenosis of each branch segment were assessed by Gensini's score. Two hundred patients underwent by MSCTCA modality were divided into four groups,respectively normal group (GS<5 scores), mild disease group (5 scores≤GS <25 scores), moderate disease group (25 scores≤GS <60 scores), severe disease group (GS≥60 scores).The data was analyzed Statistically by using SPSS17.0 software package. The quantitative data was expressed as mean±standard deviation( x±s),and the qualitative data was expressed as cases or rate(%).The both cardiac functional parameters performed by MSCTCA and TTE was analyzed by paired-t test,the correlation of the both was analyzed by using Pearson linear correlation test. Gensini's score level as a categorical variable ordering was grouped by quartile values, the group's differences were analyzed using single factor analysis of variance(ANOVA).The correlation between every cardiac functional parameters and Gensini's scores was analyzed by using Spearman linear correlation test. P<0.05 was considered statistically significance.ResultsA total of 200 patients were successfully carried out by MSCTCA,of which 30 cases were undergone by MSCTCA and TTE. The results of cardiac function such as EDV, ESV, SV, EF and FS ,measured by the both methods,were tested by paired-t test, the differences were not statistically significant (P> 0.05). EDV, LVESV, SV mean: MSCT>TTE; EF and FS mean: MSCT0.05). Compared Gensini's score with Spearman, Gensinis'score was positively correlated with EDV,ESV,LVDD,LADD and MM, conversely,Gensinis'score was negatively correlated with SV,EF and FS(P<0.05),and was no significant correlation with and CO(P>0.05). ConclusionsCompared with TTE, the quantitative evaluation of left ventricular functional parameters by MSCT is accurate and reliable, and the correlation of cardiac function measured by the both examination was quite excellent. Gensini's score(GS) of coronary artery stenosis was negatively correlated with left ventricular systolic function(EF,FS), but was positively correlated with myocardial mass(MM).that is, the more stenosis coronary artery, the worse cardiac function. Coronary artery stenosis is an important reason that caused left ventricular global systolic dysfunction and cardiac remodeling.