经食管超声评估血栓高风险患者左心耳功能状态

Prediction of high risk of thrombus by haemodynamics changes in left atrial appendage using transesophageal echocardiography

目的应用经食管超声心动图揭示左心耳的功能状态、左心耳内血流动力学的改变，及其对血栓发生高风险的预测价值。方法89例行经食管超声心动图检查的患者根据左心耳内是否存在自发性显影（SEC）分成SEC组及无SEC组，测量左心耳入口处血流排空峰值速度（LAA—EV）及充盈峰值速度（LAA—FV）、左心耳内侧壁中段收缩峰值速度（LAA—TSV）、舒张峰值速度（LAA—TDV）、左心耳排空血流传播速度（LAA—EPV），观察左心耳内彩色血流多普勒及M型彩色多普勒超声特征。结果SEC组的LAA—EV、LAA-FV、LAA-TSV、LAA-TDV、LAA—EPV较无SEC组显著降低（P〈0．05）；左心耳内血流彩色多普勒信号及M型彩色多普勒超声信号在SEC组有明显差异;随着左心耳功能受损，左心耳M型彩色多普勒超声有4种特征性类型，分别为由心耳尖部向心耳入口处依次排空（N型，正常型），心耳入口排空后紧随尖部排空的逆向排空（R型，逆反型），心耳内垂直线条（V型，垂直型），心耳内未见有效血流信号（S型，淤滞型），其中V、R和S型可能提示血栓形成前的血流动力学改变。LAA—EPV与LAA-EV显著相关（r=0．742，P〈0.001），与LAA—TSV中度相关（r=0．462，P〈0．01），LAA-EV与LAA-TSV显著相关（r=0．600，P〈0.01）。结论左心耳功能受损后左心耳室壁运动速度及血流速度显著降低，形成左心耳内血流排空的特征性改变。左心耳的功能异常可能是左心耳内血流淤滞甚至血栓形成的主要原因。特征性血流排空类型V型、R型和S型可能预示血栓形成的高风险。

Objective To study the left atrial appendage （LAA） function and haemodynamics by transesophageal eehocardiography, and predict high risk of thrombosis. Methods Eighty-nine consecutive patients were studied using transesophageal echocardiography.According to with spontaneous echo contrast （SEC） or not, all patients were divided into SEC group （n = 17） and non-SEC group （n =72）. LAA emptying peak flow velocity （LAA-EV）, filling peak flow velocity （LAA-FV） were measured by pulsed Doppler.The middle segment of the LAA medial wall systolic peak velocity （LAA-TSV） and diastolic peak velocity （LAA-TDV） were obtained by tissue Doppler imaging. LAA color Doppler and M-mode color Doppler images were acquired and derived the LAA emptying flow propagation velocity （LAA-EPV）.Results LAA-EV,LAA-FV,LAA-TSV, LAA-TDV, LAA-EPV of SEC group were lower than those of non-SEC group （ P 〈0.05）.LAA M-mode color Doppler had four characteristic patterns,N pattern （normal pattern） which flow eject from LAA apical to LAA orifice,R pattern （reverse pattern） which flow eject from LAA orifice to LAA apical, V pattern （vertical pattern） vertical signals seen in systole and without efficient flow, S pattern （stasis pattern） almost no flow signal. V, R and S patterns may indicate high risk of SEC and thrombosis. LAA-EPV had strong correlation with LAA-EV （r = 0.742, P 〈 0.001）, and moderate correlation with LAA-TSV （ r = 0.462, P 〈0.01） ,LAA-EV had strong correlation with LAA-TSV （ r = 0.600, P 〈0.01）.Conelusions LAA dysfunction would result in hypokinetic LAA wall motion and reduced blood flow velocity. Emptying abnormalities of LAA might be the important reasons for blood stasis and thrombus formation.Emptying characteristic flow patterns of V,R and S might be novel methods to predict high risk of thrombus.