早期心肌缺血状态下左心室腔内涡流特征

摘要

Objective To quantitatively characterize vortex flow in patients with early myocardial ischemia by echocardiography using vector flow mapping (VFM) and explore a new diagnostic index of early myocardial ischemia.Methods This study was conducted among 105 patients with suspected angina pectoris,who were free of a previous cardiac history with a normal ejection fraction.Patients without significant coronary artery stenoses constituted the control group (n=49) and those with significant coronary artery stenoses (n=56) constituted the early myocardial ischemia group.All the patients underwent conventional ultrasonic inspection and VFM.The velocity vector and vorticity were estimated by VFM.The vortex parameters including vortex flow,radius,diameter,area and vortex relative strength index were measured.Results No significant differences were found in the vortex parameters including the vortex flow,radius,diameter or area between the two groups (P> 0.05),but vortex relative strength index was significantly lower in early myocardial ischemia group (23.68±11.66 vs 20.20±6.29,P<0.05).Conclusion VFM is feasible for quantitative evaluation of left ventricular vorticity in healthy individuals and patients with early myocardial ischemia,and the vortex relative strength index may serve as a novel index for the diagnosis of early myocardial ischemia.%目的 运用超声心动图的血流向量成像技术(VFM)定量评估早期心肌缺血患者左室涡流的结构及位置等特征,以期发现有助于诊断早期心肌缺血的新指标.方法 疑似心绞痛患者共105例,射血分数正常,既往无心脏病史和心梗病史.依据冠脉造影结果分成早期心肌缺血组(冠脉狭窄＞75％,n=56)和对照组(无明显冠脉狭窄或＜75％,n=49例),进行常规超声检查后,行VFM检查,存图后将VFM资料导入超声工作站脱机分析得到涡流各项参数并将两组结果进行比较和统计学分析.涡流各项参数包括:涡量(QMAX)、涡流半径、直径(r、R)、面积(S)及涡强(Q/S).结果 与对照组相比,涡流的流量、面积及半径等参数无差异(P＞0.05),但是早期心肌缺血组涡强比对照组显著降低,两者比较有差异,分别为:23.68±11.66/20.20±6.29 (P＜0.05).结论 超声心动图的VFM技术对于定量评估左室涡流的可行性较高,其中涡强(Q/S)可能成为诊断早期心肌缺血的新指标.