ABSTRACT
Objective To study the left atrial appendage (LAA) function and haemodynamics by transesophageal echocardiography,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).Conclusions 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 low patterns of V,R and S might be novel methods to predict high risk of thrombus.