多巴酚丁胺负荷心肌声学造影探测冠状动脉狭窄

Detection of coronary stenosis with myocardial contrast echocardiography during dobutamine stress

目的 评价多巴酚丁胺负荷心肌声学造影（MCE）诊断冠脉狭窄的准确性。方法 在慢性冠脉狭窄闭胸犬模型上同步进行MCE和放射性微球测定心肌血流量（MBF）。结果 负荷状态时，异常冠脉供血区（MBF储备<3）呈现灌注缺损，峰值声强度（VI）较正常冠脉供血区低（33±13与48±14，P<0.01），且异常和正常冠脉供血区峰值VI比值与相应MBF比值呈良好的线性正相关（r=0.86，P<0.0001）。结论 多巴酚丁胺可作为一种负荷药物用于MCE评价冠脉狭窄。

Objective To assess the accuracy of myocardial contrast echocardiography (MCE) for detecting coronary stenosis during dobutamine stress. Methods MCE was performed using intravenously injected microbubbles (MRX-115) and radiolabled microspheres were used to measure myocardial blood flow (MBF) in 16 closed chest dogs with chronically instrumental coronary stenoses. Results Perfusion defects were seen in abnormal beds (MBF reserve <3) with dobutamine. The peak video intensity (VI) in the abnormal beds was lower (33±13 vs 48±14, P<0.01) than that in normal beds during dobutamine stress. An excellent linear relation was noted between the peak VI ratio (abnormal/normal) and that of MBF using dobutamine (r=0.86, P<0.0001). Conclusion Dobutamine may be used as a stress agent for MCE in assessing coronary stenoses.