血流向量成像技术评估左心室内压力梯度在心力衰竭患者中的应用价值

Application of vector flow mapping technique in the assessment of left intraventricular pressure gradients in heart failure patients

目的应用血流向量成像的相对压成像技术评估心动周期各期内左室内压力差(IVPDs)及左室内压力梯度(IVPGs)的变化并探讨其在心力衰竭(简称心衰)患者中的临床价值。方法入选2018年11月至2019年1月在山东大学齐鲁医院住院的左室射血分数(LVEF)<0.50的心衰患者49例(心衰组),其中射血分数减低心衰组(HFrEF组,34例),射血分数中间值心衰组(HFmrEF组,15例),并选取健康志愿者43例作为对照组。采集临床资料及超声图像,测量常规左室径线、质量、容积及收缩与舒张功能参数,应用血流向量成像技术测得等容收缩期(IC)、快速射血期(RE)、等容舒张期(IR)、快速充盈期(RF)及心房收缩期(AC)的IVPDs及IVPGs。分析心衰组及对照组间各期IVPDs及IVPGs的变化特征及与常规超声参数的相关性。结果心衰组中各期IVPDs及IVPGs均较对照组明显减低(P<0.001),其中IVPD-IR及IVPG-IR在两组中差异尤为显著。各期IVPDs及IVPGs在对照组、HFmrEF组、HFrEF组均有减低趋势(P<0.001)。IVPDs及IVPGs均与左室内径(LVID)、左室质量指数(LVMI)、左室收缩末容积(ESV)、LVEF、左室整体长轴应变(GLS)、E/e′相关(P<0.01),尤以IVPD-IR及IVPG-IR与上述指标的相关性最好。IVPD-IR和IVPG-IR对LVEF<0.5的心衰患者具有良好的诊断效能,其截断值分别为<0.73 mmHg(AUC=0.915,P<0.001)和<0.103 mmHg/cm(AUC=0.932,P<0.001)。结论当收缩功能下降时,舒张早期血流动力学严重受损。IVPG-IR作为左室舒张的标志,与左室收缩功能显著相关,可作为评估心衰患者左室收缩及舒张功能并识别心衰患者的潜在新指标。

Objective To evaluate the changes of intraventricular pressure differences(IVPDs)and intraventricular pressure gradients(IVPGs)in different phases of cardiac cycle in patients with heart failure(HF)patients by relative pressure imaging based on vector flow imaging(VFM).Methods Forty-nine HF patients with left ventricular ejection fraction(LVEF)lower than 0.50 hospitalized in Qilu Hospital of Shandong University from November 2018 to January 2019,including thirty-three patients with HF with reduced ejection fraction(HFrEF group)and fifteen patients with midrange ejection fraction(HFmrEF group),and forty-three controls were enrolled in this study.Clinical data and echocardiographic images were collected and the conventional left ventricular diameter,mass,volume,and systolic and diastolic function parameters were measured.IVPDs and IVPGs during isovolemic systole(IC),rapid ejection(RE),isovolemic diastole(IR),rapid filling(RF)and atrial systole(AC)phases were obtained by the VFM technique.The changes of IVPDs and IVPGs in different phases between the HF and control groups,and their correlations with conventional ultrasound parameters were analyzed.Results IVPDs and IVPGs in heart failure group were significantly reduced compared with the control group especially in isovolumic relaxation phase(all P<0.001).IVPDs and IVPGs showed a decreasing trend in the control group,HFmrEF group and the HFrEF group(P<0.001).IVPDs and IVPGs were correlated with LVID,LVMI,ESV,LVEF,GLS and E/e′(all P<0.01),among which IVPD-IR and IVPG-IR were best correlated.IVPD-IR and IVPG-IR had excellent diagnostic efficacy for HF patients with LVEF<0.5,with cut-off values of<0.73 mmHg(AUC=0.915,P<0.001)and<0.103 mmHg/cm(AUC=0.932,P<0.001),respectively.Conclusions Early diastolic hemodynamics are severely impaired when systolic function declines.IVPG-IR,as a marker of left ventricular diastolic function,significantly correlates with left ventricular systolic function,and can be used as a potential indicator for assessing left ventricular systolic and diastolic function in patients with heart failure and identifying patients with heart failure.