新型无创性冠状动脉血流储备检测经胸壁声学造影二次谐波多普勒技术

New noninvasive method for the evaluation of coronary flow velocity reserve:contrast-enhanced transthoracic Doppler echocardiography with second harmonic technique

目的 研究经胸壁声学造影二次谐波多普勒超声心动图探测左前降支 (LAD)冠状动脉血流储备 (CFVR)的可行性、安全性及可靠性。方法 46例患者经静脉注射利声显 ,利用二次谐波观察LAD血流 ,对多普勒血流图像质量进行分级。CFVR为注射腺苷后的最大平均血流速度与静息状态平均血流速度的比值。结果 CFVR探测的成功率为 98%。注射腺苷后 ,心率加快 ,血压减低。60 %患者有轻微副反应。CFVR为 2 84± 0 65 ,与冠状动脉内多普勒探测的结果密切相关 (r=0 87,P <0 0 0 1 )。结论 经胸壁声学造影二次谐波多普勒超声心动图可明显提高冠状动脉血流探测的成功率 ,是安全、可行。

Objective To evaluate the feasibility, safety and accuracy of detecting coronary flow velocity reserve(CFVR) by contrast enhanced transthoracic Doppler echocardiography(TTDE) with second harmonic technique Methods Doppler flow signal in the distal left anterior descending coronary artery (LAD) was assessed by contrast ehanced TTDE with second harmonic technique in 46 patients The following grade was used for color Doppler and pulsed wave(PW) Doppler signal quality: Grade I: flow mapping not obtainable or of very poor quality; Grade II: not well defined, PW Doppler tracings incomplete; Grade III: optimal recording, well delineated with complete biphasic PW Doppler tracings of systolic and diastolic flow CFVR was calculated as the ratio of hyperemic average peak velocity(APVh) to baseline average peak velocity(APVb) Results The Doppler signal quality was significantly improved by use of the echocardiographic contrast agent(Levovist) The color and PW Doppler flow was not visible only in 1(2%) patients In 45(98%) of 46 patients, CFVR was successfully determined with intravenous Levovist infusion Heart rate increased, blood pressure decreased significantly after adenosine infusion, 60% patients experienced mild side effects APVb [(18 21±7 02) cm/s], APVh [(48 46± 10 94) cm/s] and CFVR(2 84±0 65) determined from TTDE were closely correlated with those from intracoronary Doppler measurements [(APVb:(20 37±10 72) cm/s, APVh:(53 39±21 42) cm/s, CFVR:2 86±0 74] Conclusion TTDE is a feasible, safe method and provides reliable data on CFVR which can be used for the assessment of coronary stenosis, coronary microcirculation and for follow up after coronary intervention