冠脉血流显像技术无创性评价肥厚型心肌病的冠脉血流及冠脉血流储备

目的 利用经胸壁冠脉血流显像技术探测肥厚型心肌病(HCM) 左冠状动脉前降支血流,评价冠脉血流储备,并分析导致HCM 心肌缺血的原因。方法 测量10 例HCM 前降支远端冠脉动脉舒张期峰值血流速度(Vmax) 及平均血流速度(Vmean) ,经静脉注射潘生丁,并测量达到最大充血状态时的Vmax、Vmean 及注射潘生丁开始至达到最大充血状态的时间( T) ,计算冠脉血流储备(CFR) 并计算Vmax 及Vmean 与室间隔厚度( IVS) 的比值。选择10 例正常人为对照组,测量静息及最大充血状态的Vmax 及Vmean ,并计算CFR。结果 静息状态HCM 组Vmax 及Vmean 组明显高于正常组( P < 0. 001) ,最大充血状态时HCM 组与正常组间无差异( P > 0. 05) , T 明显延迟( P < 0. 001) ,CFR 明显低于正常组( P < 0. 001) 。静息状态HCM 组Vmax/ IVS、Vmean/ IVS 明显低于正常组( P< 0. 01) ,最大充血状态时其比值更低( P < 0. 001) 。结论 经胸壁冠脉血流显像是一种准确有效地测量HCM 冠脉血流,评价冠脉血流储备的无创性检测方法。导致HCM 患者CFR 减低的原因是冠状动脉小血管结构的改变使其扩张能力减低。而HCM 心肌缺血与冠脉血流与室间隔厚度不适应及CFR 减低有关。

Noninvasive Assessment of Coronary Flowand Flow Reserve of Hypertrophic Cardiomyopathy by a New Coronary Flow Imaging System

Objective The aim is to evaluate the coronary flow reserve of normal subjects and patients with hypertrophic cardiomyopathy (HCM) by transthoracic coronary flow imaging system so as to analyze the cause of myocardial ischemiacomplicated with HCM. Methods Distal segments of left descending arteries in 10 patients were examined to record flow Doppler spectrum and the floowing indices were measured :peak velocity (Vmax) ,mean velocity (Vmean) respectively atrest and during hyperemia after infusion of Dipyridamole ,and time interval ( T) from the onset to the maximal hyperemia.Coronary flow reserve was calculated as the ratio of Vmax or Vmean to the thickness of interventricular septum. 10 normalsubjects were selected as control group. And such indices were measured and calculated also. Results Vmax and Vmean inpatient group were larger than those in control group at rest significantly ( P < 0. 001) .But there were no significant difference of the two indices between the two groups. ( P > 0. 05) . T was prolonged and CFR Vmax/ IVS and Vmax/ IVS wereby far lower in patient group both at rest and maximal hyperemia ( P < 0. 001 ,0. 01 ,0. 01 ,0. 001 ,0. 001) . Conclusion Transthopacic coronary flow imaging is an effective noninvasive technique to measure coronary hemodynamics accurately.The decrease of CFR in patients with HCM resulted from the structural change and impotent expansion of coronary anteroles. Myocardial ischemia was related with the mismatch of coronary flow with IVS thickness and with the decrease ofCFR.