title: Detection of coronary stenosis with myocardial contrast echocardiography using regadenoson, a selective adenosine A2A receptor agonist.
abstract: OBJECTIVE
  Regadenoson is comparable to adenosine in pharmacologic radionuclide stress tests but has not been studied with stress myocardial contrast echocardiography. This study assessed the haemodynamic profile and ability of regadenoson, a novel selective A(2A) receptor agonist, to detect coronary artery stenosis during myocardial contrast echocardiography.
  
  
  RESULTS
  Myocardial contrast echocardiography was performed to measure myocardial blood volume, myocardial blood flow velocity, and total regional myocardial blood flow before and after administration of regadenoson (5 µg kg(-1), 10 s bolus) in 10 open-chest dogs with mild-to-moderate coronary stenosis that was not flow limiting at rest. Regadenoson decreased blood pressure but did not change heart rate. It increased coronary blood flow significantly (P < 0.05) for 30 min, which was attenuated in proportion to coronary stenosis severity. Whereas myocardial blood volume maximally increased by 0.5-0.75-fold in the control region, it did not change in the region supplied by the non-flow limiting stenosis. Perfusion defects were visually and quantitatively detectable for as long as 10 min after administration of regadenoson. No arrhythmias were noted with regadenoson either prior to or during myocardial contrast echocardiography.
  
  
  CONCLUSIONS
  Regadenoson can be used as a vasodilator stress agent with myocardial contrast echocardiography to detect the presence of physiologically significant coronary stenosis. The optimum time for image acquisition was 3-10 min after drug administration.
authors: Portland Veterans Affairs Medical Center, 3710 SW US Veterans Hospital Road, Portland, OR 97239, USA. lee@ohsu.edu
authors: D Elizabeth
authors: DE
authors: Le
authors: Thanjavur
authors: T
authors: Bragadeesh
authors: Yan
authors: Y
authors: Zhao
authors: Yue-Gang
authors: YG
authors: Wang
authors: Daogang
authors: D
authors: Zha
authors: Sanjiv
authors: S
authors: Kaul
mesh_terms: D058917:Adenosine A2 Receptor Antagonists; D000704:Analysis of Variance; D001011:Aorta / Q000187:drug effects; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D004452:Echocardiography / Q000295:instrumentation*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D055414:Myocardial Perfusion Imaging; D009206:Myocardium / Q000473:pathology*; D011687:Purines; D011720:Pyrazoles; D013318:Stroke Volume; D014665:Vasodilator Agents; D016277:Ventricular Function, Left
chemical_list: D058917:Adenosine A2 Receptor Antagonists; D011687:Purines; D011720:Pyrazoles; D014665:Vasodilator Agents; C430916:regadenoson