Galiuto Leonarda, Sestito Alfonso, Barchetta Sabrina, Sgueglia Gregory A, Infusino Fabio, La Rosa Claudio, Lanza Gaetano, Crea Filippo
Institute of Cardiology, Catholic University of the Sacred Heart, Rome, Italy.
Am J Cardiol. 2007 May 15;99(10):1378-83. doi: 10.1016/j.amjcard.2006.12.070. Epub 2007 Mar 28.
Data on coronary flow reserve (CFR) in patients with syndrome X are still controversial. Further, noninvasive evaluation of epicardial and microvascular flow reserves in these patients has never been performed. In 17 patients with syndrome X and in 17 age- and gender-matched control subjects, CFR in the mid left anterior descending coronary artery (LAD) was evaluated by transthoracic color and pulse-wave Doppler using a 7-mHz probe (Sequoia, Siemens). Peak diastolic LAD flow was calculated at rest and at peak adenosine (140 microg/kg/min intravenously in 90 seconds). Myocardial contrast echocardiography (MCE) was performed at rest and during adenosine use by real-time cadence pulse sequencing and intravenous SonoVue (Bracco; 5 ml at 1 ml/min) and microvascular blood volume (A), velocity (beta), and flow (Axbeta) by replenishing curves (y = A[1 - e(betat)]). CFR was measured by Doppler echocardiography as an adenosine/rest velocity ratio and by MCE as a microvascular volume, velocity, and flow adenosine/rest ratio. Compared with controls, patients with syndrome X demonstrated lower LAD CFR and velocity and flow microvascular flow reserves (p <0.01, <0.005, and <0.005, respectively). In patients with syndrome X, those with angina and ST-segment depression during adenosine testing had even lower LAD CFR and velocity and flow microvascular flow reserves compared with those with no symptoms (p <0.0001, <0.0001, and <0.005, respectively). LAD CFR demonstrated a significant linear correlation with velocity microvascular flow reserve (r = 0.92, p <0.0001) and flow microvascular flow reserve (r = 0.77, p <0.0001). In conclusion, CFR in the LAD, successfully evaluated by transthoracic Doppler echocardiography and MCE, is significantly decreased in patients with syndrome X and even more in those with angina pectoris and ST-segment depression during adenosine testing. Thus, noninvasive evaluation of CFR by echocardiography is feasible and provides information on the severity of microvascular impairment.
X综合征患者的冠状动脉血流储备（CFR）数据仍存在争议。此外，从未对这些患者的心外膜和微血管血流储备进行过无创评估。在17例X综合征患者和17例年龄及性别匹配的对照受试者中，使用7兆赫兹探头（西门子Sequoia）通过经胸彩色和脉冲波多普勒评估左冠状动脉前降支（LAD）中段的CFR。在静息状态和腺苷峰值（90秒内静脉注射140微克/千克/分钟）时计算舒张末期LAD峰值血流。通过实时节奏脉冲序列和静脉注射声诺维（意大利Bracco公司；以1毫升/分钟的速度注射5毫升）在静息状态和使用腺苷期间进行心肌对比超声心动图（MCE）检查，并通过补充曲线（y = A[1 - e(betat)]）计算微血管血容量（A）、速度（β）和血流量（A×β）。通过多普勒超声心动图将CFR测量为腺苷/静息速度比值，通过MCE将其测量为微血管容量、速度和血流量的腺苷/静息比值。与对照组相比，X综合征患者的LAD CFR以及速度和血流量的微血管血流储备较低（分别为p <0.01、<0.005和<0.005）。在X综合征患者中，腺苷试验期间出现心绞痛和ST段压低的患者与无症状患者相比，LAD CFR以及速度和血流量的微血管血流储备更低（分别为p <0.0001、<0.0001和<0.005）。LAD CFR与速度微血管血流储备（r = 0.92，p <0.0001）和血流量微血管血流储备（r = 0.77，p <0.0001）呈显著线性相关。总之，经胸多普勒超声心动图和MCE成功评估的LAD CFR在X综合征患者中显著降低，并在腺苷试验期间出现心绞痛和ST段压低的患者中降低得更多。因此，通过超声心动图对CFR进行无创评估是可行的，并可提供有关微血管损伤严重程度的信息。
