血流向量成像技术在慢性心力衰竭患者左心室能量损耗评估中的应用价值

Role of vector flow mapping in assessing left ventricular energy loss in patients with chronic heart failure

目的应用血流向量成像技术检测慢性心力衰竭患者左心室能量损耗指标,探讨其评估左心室收缩及舒张功能的价值。方法65例慢性心力衰竭患者,根据心力衰竭分类指南分为射血分数保留(heart failure with preserved ejection fraction,HFpEF)组32例,射血分数减低(heart failure with reduced ejection fraction,HFrEF)组33例;同期体检健康者32例为对照组。3组采用免疫分析法检测血清N末端脑钠肽前体(N-terminal pro-B-type natriuretic peptide,NT-proBNP)水平;行超声心动图测量左心室舒张末期内径(left ventricular end-diastolic dimension,LVEDD)、左心室收缩末期内径(left ventricular end-systolic dimension,LVESD)、左心室舒张末期容积(left ventricular end-diastolic volume,LVEDV)、左心室收缩末期容积(left ventricular end-systolic volume,LVESV)、左室射血分数(left ventricular ejection fraction,LVEF)及二尖瓣前向血流速度E峰、间隔壁及侧壁心肌运动速度e',计算E/e';应用血流向量成像技术在能量损耗模式下测量舒张期(等容舒张期、快速充盈期、心房收缩期)及收缩期(等容收缩期、快速射血期)左心室整体平均能量损耗(average energy loss,EL-ave);采用Pearson相关法分析慢性心力衰竭患者收缩期、舒张期EL-ave与E/e'的相关性。结果HFrEF组血清NT-proBNP水平[(6785.56±1254.34)ng/L]高于HFpEF组[(165.69±20.34)ng/L]和对照组[(27.46±17.42)ng/L](P<0.05),左心房前后径[(52.45±5.05)mm]、LVEDD[(69.56±7.89)mm]、LVESD[(53.49±4.87)mm]、LVEDV[(235.67±7.89)mL]、LVESV[(142.45±7.01)mL]、E/e'(23.64±2.58)均大于HFpEF组[(38.49±5.42)mm、(48.65±6.12)mm、(33.15±4.01)mm、(110.52±6.67)mL、(46.67±6.02)mL、15.43±2.03]和对照组[(33.68±6.21)mm、(48.32±6.21)mm、(29.47±3.34)mm、(98.67±7.33)mL、(45.45±5.98)mL、9.12±1.35](P<0.05),LVEF[(32.71±6.02)%]低于HFpEF组[(63.35±5.89)%]和对照组[(65.54±5.43)%](P<0.05);HFpEF组血清NT-proBNP水平高于对照组(P<0.05),左心房前后径、E/e'均大于对照组(P<0.05),LVEDD、LVEDV、LVESD、LVESV、LVEF与对照组比较差异无统计学意义(P>0.05)。HFpEF组快速充盈期(20.24±4.65)、心房收缩期(7.56±2.63)、等容收缩期(10.01±2.97)、快速射血期(5.82±1.78)EL-ave均高于HFrEF组(2.82±0.49、3.17±1.02、0.16±0.05、0.83±0.14)和对照组(13.12±3.69、3.34±0.97、4.00±1.47、2.27±1.68)(P<0.05),等容舒张期EL-ave(1.76±0.58)高于HFrEF组(0.36±0.08)(P<0.05),与对照组(2.20±0.58)比较差异无统计学意义(P>0.05);HFrEF组等容舒张期、快速充盈期、等容收缩期、快速射血期EL-ave均低于对照组(P<0.05)。慢性心力衰竭患者等容收缩期EL-ave与LVEF呈正相关(r=0.582,P=0.017),等容舒张期、快速充盈期EL-ave与E/e'呈负相关(r=-0.768,P=0.001;r=-0.605,P=0.021)。结论血流向量成像技术可定量慢性心力衰竭患者左心室EL-ave,EL-ave在反映HFpEF患者左心室收缩及舒张功能改变上较LVEF敏感。

Objective To detect the left ventricular energy loss parameter with vector flow mapping(VFM)in patients with chronic heart failure(CHF),and to investigate its value to the assessment of left ventricular systolic and diastolic function.Methods According to the guidelines for the classification of heart failure,65patients with CHF were divided into 32patients with preserved ejection fraction(HFpEF group)and 33patients with reduced ejection fraction(HFrEF group),and another 32healthy volunteers in the same period were as controls(control group).The levels of N-terminal pro-B-type natriuretic peptide(NT-proBNP)were measured by immunoassay in three groups.The left ventricular end-diastolic dimension(LVEDD),left ventricular end-systolic dimension(LVESD),left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),left ventricular ejection fraction(LVEF),mitral valve E peak,and E/e'values of septal wall and lateral wall were measured by echocardiography,and the E/e'was calculated.The global mean energy loss(EL-ave)values of the left ventricle in diastolic period(isovolumic diastolic period,rapid filling period,atrial systolic period)and systolic period(isovolumic systolic period,rapid ejection period)were measured by VFM in the energy loss mode in three groups.Pearson correlation was used to analyze the correlations of systolic and diastolic EL-ave values with E/e'in CHF patients.Results The serum NT-proBNP level was higher in HFrEF group[(6785.56±1254.34)ng/L]than that in HFpEF group[(165.69±20.34)ng/L]and control group[(27.46±17.42)ng/L](P<0.05),left atrial dimension,LVEDD,LVEDS,LVEDV,LVESV and E/e'were greater in HFrEF group[(52.45±5.05)mm,(69.56±7.89)mm,(53.49±4.87)mm,(235.67±7.89)mL,(142.45±7.01)mL,23.64±2.58]than those in HFpEF group[(38.49±5.42)mm,(48.65±6.12)mm,(33.15±4.01)mm,(110.52±6.67)mL,(46.67±6.02)mL,15.43±2.03]and control group[(33.68±6.21)mm,(48.32±6.21)mm,(29.47±3.34)mm,(98.67±7.33)mL,(45.45±5.98)mL,9.12±1.35](P<0.05),and LVEF was lower in HFrEF group[(32.71±6.02)%]than that in HFpEF group[(63.35±5.89)%]and control group[(65.54±5.43)%](P<0.05).The level of serum NT-proBNP was higher in HFpEF group than that in control group(P<0.05),left atrial dimension and E/e'were greater than those in control group(P<0.05),and there were no significant differences in LVEDD,LVEDV,LVESD,LVESV and LVEF between HFpEF group and control group(P>0.05).The EL-ave values in rapid filling period,atrial systolic,isovolumic systolic and rapid ejection period were higher in HFpEF group(20.24±4.65,7.56±2.63,10.01±2.97,5.82±1.78)than those in HFrEF group(2.82±0.49,3.17±1.02,0.16±0.05,0.83±0.14)and control group(13.12±3.69,3.34±0.97,4.00±1.47,2.27±1.68)(P<0.05).The EL-ave value in isovolumic diastolic period was higher in HPpEF group(1.76±0.58)than that in HFrEF group(0.36±0.08)(P<0.05),and showed no significant difference compared with control group(2.20±0.58)(P>0.05).The EL-ave values in isovolumic diastolic period,rapid filling period,isovolumic systolic period and rapid ejection period were lower in HFrEF group than those in control group(P<0.05).The EL-ave in isovolumic systolic period was positively correlated with LVEF(r=0.582,P=0.017),and the EL-ave values in isovolumic diastolic period and rapid filling period were negatively correlated with E/e'(r=-0.768,P=0.001;r=-0.605,P=0.021).Conclusion VFM can quantitatively analyze left ventricular EL-ave in patients with CHF,and is more sensitive in reflecting the changes of left ventricular systolic and diastolic function than LVEF.