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Objective:To investigate the diagnostic value of postsystolic shortening (PSS) and early systolic lengthening (ESL) on myocardial microvascular dysfunction in patients with ST-segment elevation myocardial infarction (STEMI) after percutaneous coronary intervention (PCI).Methods:A total of 83 patients with STEMI who received emergency PCI in Renmin Hospital of Wuhan University from June to October 2021 were retrospectively collected. All patiets underwent two-dimensional echocardiography and myocardial contrast echocardiography (MCE) within 7 days after PCI. The patients were divided into global normal perfusion group and poor perfusion group according to global myocardial perfusion score index (MPSI). Left ventricular myocardium was divided into left anterior descending branch (LAD), left circumflex branch (LCx) and right coronary artery (RCA) regions, which were divided into regional normal perfusion group and poor perfusion group based on whether there were segments with microvascular dysfunction. Left ventricular end-systolic volume (LVESV) and left ventricular ejection fraction (LVEF) were measured by modified biplane Simpson method. Tomtec software was used to obtain conventional echocardiographic parameters, global longitudinal strain (GLS), as well as PSS and ESL parameters including postsystolic index (PSI), duration of postsystolic shortening (PSSduration), early systolic index (ESI) and duration of early systolic lengthening (ESLduration). Differences of parameters of global normal and poor perfusion groups, as well as regional normal and poor perfusion groups were compared. ROC curve was used to analyze the diagnostic value of PSS and ESL parameters and GLS in myocardial regions with microvascular dysfunction.Results:Significant differences were observed in LVEF, LVESV, GLS, PSI, ESI and PSSduration between global poor perfusion group and global normal perfusion group (all P<0.05). Compared with regional normal perfusion group, PSI, ESI and ESLduration of LAD and LCx regions, as well as PSI of RCA region in regional poor perfusion group were increased (all P<0.05). For GLS in different myocardial regions, LAD-GLS was the only parameter that decreased in regional poor perfusion group compared to regional normal perfusion group ( P<0.05). ROC curve analysis showed LAD-PSI, LAD-GLS, LCx-PSI, LCx-ESLduration and RCA-PSI were valuable parameters for diagnosis of myocardial microvascular dysfunction in different regions, among which LAD-PSI had the highest area under curve (AUC=0.809). Conclusions:PSS and ESL parameters are helpful for early diagnosis of myocardial microvascular dysfunction in STEMI patients after PCI, and can provide regional myocardial perfusion information according to the blood supply of different coronary arteries.
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Objective:To evaluate the application of Quantitative tissue velocity imaging(QTVI) in assessing the left ventricular (LV) systolic function in Children with dilated cardiomyopathy(DCM).Methods:Fifteen consecutive children with DCM were included in the present study,who were divided into group A(with light heart failure) and group B(with moderate and severe heart failure).Twelve children without any cardiac diseases were as controls.The dynamic tri-plane QTVI images of apical four-chamber,LV two-chamber and LV long-axis views were acquired simultaneously and the myocardial velocity curves in basal and middle segments were analyzed.Results:(1)The peak systolic velocity (Vs)redueed generally in group A and B compared with that in controls,especially in group B(P0.05).(2)There were forty-two segments with the velocity of postsystolie shortening(PSS) more than that of the systole in DCM group,among which thirty segments(71.43%)were from group B,and twelve segrnents(28.57%)from group A. Analyzed with strain,twenty-one segments (50.00%)were actively shortened and eleven segments (26.19%)were paradoxical motion.Conclusion:QTVI can assess LV systolic function accurately in Children with DCM.