二维斑点追踪技术评价代谢综合征患者右室收缩功能及其与心外膜脂肪厚度的关系

Evaluation of right ventricular systolic function and relationship with epicardial fat thickness in patients with metabolic syndrome by two-dimensional speckle tracking imaging

目的应用二维斑点追踪技术(2D-STI)评价代谢综合征(MS)患者右室收缩功能,探讨其与心外膜脂肪厚度(EAT)的关系。方法选取65例MS患者(MS组)及同期健康体检者35例(对照组),收集各代谢因素包括年龄、性别、体质量指数(BMI)、腰围身高比(WtHR)、收缩压、舒张压、空腹血糖(Glu)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、总胆固醇(TC);应用常规超声心动图获取右室流出道近端内径(RVOT prox)、右室基底部内径(RV-B)、右室中部内径(RV-M)、右室长径(RV-L)、三尖瓣前叶瓣环收缩期位移(TAPSE)、三尖瓣环收缩期运动速度(S’)、三尖瓣口舒张早期与晚期峰值流速比值(E/A)、三尖瓣口舒张早期峰值流速与三尖瓣环舒张早期运动峰值速度比值(E/e’)、EAT、右室面积变化率(FAC);2D-STI技术获取右室整体纵向应变(RVGLS)、右室游离壁应变(RVFWS),比较两组上述参数的差异;分析RVFWS与各代谢因素之间的相关性。应用多元线性回归分析RVFWS的独立影响因素;采用Bootstrap自助抽样法分析临床指标是否介导EAT与RVFWS之间的关联。结果两组心率及各代谢因素比较显示,与对照组比较,MS组BMI、收缩压、舒张压、WtHR、Glu、TG、LDL-C、TC均增高,HDL-C减低,差异均有统计学意义(均P<0.05);两组年龄、性别、心率比较差异均无统计学意义。两组超声心动图参数比较显示,与对照组比较,MS组E/e’、EAT均增高,TAPSE、RVGLS、RVFWS均减低,差异均有统计学意义(均P<0.05);其余超声心动图参数比较差异均无统计学意义。MS组RVFWS与EAT、年龄、收缩压、舒张压、BMI、WtHR、Glu、TG、LDL-C、TC均呈负相关,与HDL-C呈正相关(均P<0.05);EAT、收缩压、Glu、TG、HDL-C均为RVFWS的独立影响因素(均P<0.05);EAT对RVFWS有直接影响,且收缩压、Glu、TG、HDL-C部分介导EAT对RVFWS的影响。结论2D-STI能敏感、准确地评价MS患者早期右室收缩功能。EAT为RVFWS的独立影响因素,可通过循环代谢部分介导其对右室功能产生影响。

Objective To evaluate right ventricular systolic function in patients with metabolic syndrome(MS)by two-dimensional speckle tracking imaging(2D-STI),and to explore the relationship with epicardial fat thickness(EAT).Methods A total of 65 MS patients(MS group)and 35 healthy subjects(control group)were selected.Metabolic factors including age,gender,body mass index(BMI),waist-to-height ratio(WtHR),systolic blood pressure,diastolic blood pressure,fasting blood glucose(Glu),triglyceride(TG),high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C),and total cholesterol(TC)were collected.The proximal diameter of the right ventricular outflow tract(RVOT),right ventricular base diameter(RV-B),right ventricular middle diameter(RV-M),right ventricular length diameter (RV-L),tricuspid annular plane systolic excursion(TAPSE),tricuspid annular systolic peak velocity(S’),the ratio of early andlate peak diastolic flow rates of tricuspid valve orifice(E/A),the ratio of peak early diastolic tricuspid orifice flow velocity andearly diastolic tricuspid annular motion velocity(E/e’),EAT,right ventricular fractional area change(FAC)were obtained byconventional echocardiography. Right ventricular global longitudinal strain(RVGLS) and right ventricular free wall strain(RVFWS)were obtained by 2D-STI technology.The differences of the above parameters between the two groups were compared.The correlation between RVFWS and metabolic factors was analyzed. The independent influence factors of RVFWS wereanalyzed by multiple linear regression analysis.The Bootstrap method was used to analyze whether clinical indicators mediatedthe relationship between EAT and RVFWS.Results Comparison of the heart rate and metabolic factors in two groups showedthat compared with the control group,the metabolic factors including BMI,systolic blood pressure,diastolic blood pressure,WtHR,Glu,TG,LDL-C,and TC were increased in the MS group,while HDL-C was decreased,and the differences werestatistically significant(all P<0.05).There were no significant differences in age,gender and heart rate between the two groups.Comparison of echocardiographic parameters in two groups showed that compared with the control group,the echocardiographicparameters E/e’and EAT in the MS group,while TAPSE,RVGLS and RVFWS were decreased,and the differences werestatistically significant(all P<0.05).No significant differences in other echocardiographic parameters were observed.The RVFWSin the MS group showed significant negative correlations with EAT,age,systolic blood pressure,diastolic blood pressure,BMI,WtHR,Glu,TG,LDL-C and TC,while showed a positive correlation with HDL-C(all P<0.05). The EAT,systolic bloodpressure,Glu,TG and HDL-C were independent influences of RVFWS(all P<0.05).The EAT had a direct impact on RVFWS,while systolic blood pressure,Glu,TG,and HDL-C partially mediated this effect.Conclusion 2D-STI can provide sensitiveand accurate assessment of early right ventricular systolic function in patients with MS.EAT is an independent influencing factorof RVFWS in patients with MS,which can partially mediate its detrimental impact on the right ventricle through circulatorymetabolism.