Temporal changes of left ventricular mechanical dyssynchrony early after acute myocardial infarction assessed by two-dimensional speckle tracking imaging and real-time three-dimensional echocardiography: a comparison with single photo emission computed tomography gated myocardial perfusion imaging measurement / 中华超声影像学杂志

ABSTRACT

Objective To evaluate the dynamic changes of left ventricular mechanical synchrony in the early period after acute myocardial infarction (AMI) by two-dimensional speckle tracking imaging (2D-STI) and real time three-dimensional echocardiography (RT-3DE),and analyze the correlation with phase analysis of single photo emission computed tomography gated myocardial perfusion imaging (SPECT GMPI) in porcine models,and further to investigate the clinical significance of left ventricular mechanical dyssynchrony in patients with AMI.Methods Bama minipigs(n =11) were subjected to left anterior descending (LAD) occlusion by balloon to introduce AMI porcine models.All animals underwent 2D-STI and RT-3DE at the baseline (before AMI),1 day,1 week and 4 weeks after LAD occlusion,respectively.In addition,SPECT GMPI was measured at baseline and 1 day after AMI.Data was analyzed and compared the dynamic changes of left ventricular mechanical synchrony before and after AMI.Then the correlation between echocardiography and SPECT GMPI in evaluating left ventricular mechanical synchrony before and after AMI were calculated.Results Eight pigs were successfully established as AMI models and complete the study.SPECT GMPI,2D-STI and RT-3DE showed that the left ventricular mechanical synchrony indexes were significantly higher at 1 day after AMI than those before AMI,which means the appearance of left ventricular mechanical dyssynchrony.Compared with those 1 day after AMI,GLS,Time SD,Tmsv16-SD％ and Tmsv16-Dif％ did not change significantly at 1 week after AMI,but they significantly increased at4 weeks after AMI (all P ＜0.05).At baseline and 1 day after AMI,the GLS measured by 2D-STI and the SPECT GMPI parameter phase bandwidth (BW) showed good correlation(r =0.708-0.719,P ＜0.05),Time SD was significantly correlated with the SPECT GMPI parameter phase standard deviation (SD)(r =0.717-0.830,P ＜0.05),while Tmsv16-Dif％ derived from RT-3DE had a better positive correlation with BW (r =0.713-0.857,P ＜0.05),as similar as Tmsv16-SD％ with SD(r =0.803-0.957,P ＜0.05).Conclusions Left ventricular mechanical dyssynchrony is present 1 day after AMI.Compared with that 1 day after AMI,left ventricular mechanical dyssynchrony doesn't change significantly at 1week after AMI,but further aggravates at 4 weeks after AMI.The parameters of 2D-STI and RT-3DE have good correlation with the mechanical synchrony parameters measured by SPECT GMPI.2D-STI and RT-3DE can be used as reliable methods to evaluate left ventricle mechanical dyssynchrony early after AMI.