超声背向散射技术评价冠状动脉慢血流患者的左心室心肌组织特征

Left ventricular myocardial tissue characterization in patients with coronary slow flow by integrated backscatter

目的:应用超声背向散射(IBS)技术评价冠状动脉慢血流(CSF)患者的左心室心肌组织声像学特征,初步探讨CSF患者心肌组织纤维化的变化.方法:选择可疑冠心病行冠状动脉造影检查的患者,纳入诊断为CSF患者49例(CSF组)和非慢血流患者45例(N-CSF组),行超声心动图检查检测左心室收缩及舒张功能,同时采用超声IBS技术检测左心室基底段前间隔、后壁和心包的背向散射积分(IB),并计算校正背向散射积分(cIB).结果:①CSF组和N-CSF组比较,二尖瓣舒张早期血流速度(E)、早期血流速度/晚期血流速度比值(E/A)和二尖瓣环间隔速度(e')减小(P<0.01);左心室射血分数(LVEF)减小(P<0.01),但在正常范围内.②CSF组cIB显著大于N-CSF组(P<0.01),且cIB与冠状动脉血流平均帧数(mTFC)呈正相关(r=0.33,P<0.01).结论:CSF患者左心室舒张功能减低,左心室心肌cIB增大,提示可能出现心肌纤维化,且冠状动脉血流速度越慢,心肌纤维化程度越重.

Objective:Ultrasound integrated backscatter(IBS)technique was used to evaluate the acoustic characterization of left ventricular myocardial tissue in patients with coronary slow flow(CSF),and to detect myocardial fibrosis in CSF patients.Methods:Among patients underwent coronary angiography for suspected coronary heart disease,49 patients(CSF group)diagnosed with CSF and 45 patients(N-CSF group)without CSF were recruited.Echocardiography was performed to assess left ventricular systolic and diastolic function.IBS was used to detect integrated backscatter(IB)of anterior septum,posterior wall and pericardium of left ventricular basal segment.The calibrated integrated backscatter(cIB)was calculated.Results:①Compared to N-CSF group,diastolic mitral inflow velocity E peak(E),E peak/A peak(E/A ratio)and early diastolic velocity at mitral valve annulus septal site(e’)reduced in CSF group(P<0.01).Left ventricular ejection fraction(LVEF)decreased(P<0.01),but was within the normal range.②Compared to N-CSF group,cIB increased in CSF group(P<0.01),which was positively correlated with coronary mean thrombolysis in myocardial infarction(TIMI)frame count(TFC)(r=0.33,P<0.01).Conclusion:Left ventricular diastolic function decreased and cIB increased in CSF patients,suggesting that myocardial fibrosis may exist and the degree of fibrosis increased with the decrease of coronary flow.