| Objective:The analysis of velocity and strain that Doppler Tissue Imaging(DTI) obtain was extensively approved to assess regional systolic function of the left ventricle (LV), but the clinical practice was confined by its angle independence.Recently Speckle Tracking Imaging (STI) is a new technique that assess the long-axis global and regional systolic function of LV base on two dimension greyscale video. It is the principle of STI that track natural phonics spots scattering in the myocardium and tissue synchronous movement, by means of tracking its variation of geometric shift-ing to obtain strain parameter of myocardium, so it is of no angle independence.This study sought to assess the long-axis global and regional systolic function of the left ventricle (LV) in acute myocardial infarction(AMI) patients with type 2 diabetes mellitus (T 2DM) using two-dimensional speckle tracking imaging (STI).Methods:Object of studyEighty subjects with AMI patients with T 2DM were selected that 42 men and 38 women in it, apart from hypertension and cardiomyopathy etc. impacting the function of heart. Sixty-eight patients among it were divided into two groups according to left venricular ejection fraction(LVEF):1.Normal LV ejection fraction (LVEF)group (A group):LVEF≥50%(n=36),including 19 men and 17 women; 2.Abnormal LVEF group (B group):LVEF≤50%(n=32), including 18 men and 14 women. And 58 AMI patients with T 2DM among it were subjected as AMI with DM group (A+D group).68 patients with AMI (36 men and 32 women)and 39 patients with DM(20 men and 19 women) were subiected as AMI group and DM group respectively matching AMI with DM group.52 healthy (28 men and 24 women) subjects are selected simultaneous to be N group.Instrument and equipmentWe use GE Vivid 7 Dimension Colour ultrasonic diagnosticunit pruducted by GE, M3S probe, the frame frequency of image is 40-60 f/s, the images are stored in DVD, the off-line analysis is made on Echo PAC workstation.Method of experiment1. GE Vivid 7 ultrasound diagnostic applications, the conventional two-dimensional echocardiography, conventional measurment data including the Left Ventricular diastolic diameter (LVDd), Left Ventricular systolic diameter (LVDs), Left Ventricular Ejection Fraction (LVEF) and E/A, peak strain of segments of LV in apical long-axis, four-chamber, and two-chamber views was evaluated, and peak strain of segents of LV wall in the long axis at basal, middle and apical levels were assessed to caculate average peak strain of basalsegment, middlesegment and apicalsegment and global longitudinal strain (GLS) of LV.2. The statistics of SPSS 17.0 was put to use, the caculating data was presented by means±standard (x±s), the comparing in the groups would adopt the analysis of variance,the comparing between two groups would adopt the analysis of SNK, and correlation would adopt the analysis of linear relation, p<0.05 shows statistics significant.Results:1. In N group, the variation of all LV segments was basalsegment< middlesegment< apicalsegent, LVAW< LVLW. The normal curve was smoothing, downward, negtive waves.But in AMI patients with T 2DM, there was no regular patterns, the curve is clutter, more smooth and inversion. The peaks train of LV segments in AMI with DM group were significant lower than that of N group (p<0.01).2. Apart from LW at basal level, peak strain of the others segments in A+D group, AMI group and DM group were obviously lower than that of N group (P<0.01或0.05). Each average peak strain of A+D group, AMI group and DM group was obviously lower than that of the control group (p<0.01). Peak strain of AS in middle and apical levels, AW in basal and middle levels, PW in basal and apical levels, PS in basal level in A+D group were signicantly lower than that of DM group (p<0.01或0.05). Apart from average peak strain of apicalsegment in A+D group was higher than that of AMI group (p< 0.05), peak strain of the others walls in A+D group and AMI group were no difference (p>0.05).GLS of A+D group and AMI group were significantly lower than that of N group and DM group (p<0.01), and GLS of DM group was obviously lower than N group (P<0.01), too.But compared with AMI group, GLS of A+D group was no difference (P>0.05)3. Peak strain of AS in middle and apical level, IW and PW in apical level and average peak strain of apicalsegment in A+D group (A, B group) were signicantly lower than that of DM group (p<0.01), but that was no difference with AMI group.Average peak strain of segments and global longitudinal strain(GLS) in B group were significantly lower than that of A group(p<0.01), and average peak strain of middlesegment and GLS in B group were obviously lower than that of AMI and DM group (p<0.01或p<0.05).However, average peak strain of apicalsegment and GLS in A group were higher than that of AMI group. The difference of two-dimen-sional strain indifferent groups show up as apicalsegment, secondly middlesegment, but basalsegment at least.4. The analysis result of correlation indicated there was a statistically significant correlation between GLS of LV and LVEF(r=0.443, P=0.000), and the correlation was found between GLS and E/A(r=0.275, P=0.003).Conclusions:1. The law in the longitudinal strain of normal LV myocardium:basalsegment< middlesegment< apicalsegment, LV anterior wall< LV lateral wall; strain rate of apicalsegment was the highest.2. Peak strain of the most segments and GLS of AMI+DM patients were significantly lower than that of AMI patients and DM patients, which show up the global and regional systolic function would weakener on the influence of AMI and DM.3. AMI+DM patients who face heart failure show up peak strain of walls and GLS of AMI+DM patients more lower. It points out the crowd just mentioned would be confronted with more clinical risk.4. There was a statistically significant correlation between GLS of LV and LVEF, which points out GLS would act as a index to assess systolic function of LV. |
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