Assessment of myocardial perfusion by myocardial contrast echocardiographyusing harmonic power and the transvenous contrast agent SHU 563A in acute coronary occlusion and after reperfusion

Background: Harmonic power Doppler imaging is a novel technique for the ass essment of myocardial perfusion by contrast echocardiography. In this study , we examined whether myocardial contrast echocardiography using harmonic p ower Doppler and the new transvenous contrast agent SHU 563A can identify m yocardial perfusion defects during coronary occlusion and reperfusion. Meth ods: To assess the potential of this technique. we occluded either the left anterior descending coronary artery or the circumflex coronary artery for 2 to 3 h followed by 1 h reperfusion in 10 dogs in an open chest model. Aft er transvenous administration of SHU 563A, an air-filled, polymeric contras t agent, myocardial contrast echocardiography was performed in short and lo ng axis views with triggered harmonic power Doppler imaging after coronary occlusion and reperfusion. Post-mortem triphenyl tetrazolium chloride stain ing was performed to verify infarction. Harmonic power Doppler and anatomic data were analyzed by independent observers. Results: During coronary occl usion, harmonic power Doppler showed perfusion defects in all 10 dogs. The defect size in the short axis view at papillary muscle level ranged 4-51% ( 14 +/- 13%) and 3-43% (16 +/- 10%) in the long axis view (% total LV slice area). After reperfusion (1 h) and infusion of dipyridamole (0.56 mg/kg), p ower Doppler demonstrated perfusion defects in seven dogs: 0-20% (9 +/- 8%) (short axis view) and 0-48% (13 +/- 14%) (long axis clew). Five dogs showe d anatomic infarction. The anatomic infarct area was 0-18% (6 +/- 8%) (slic es: corresponding to the echocardiographic short axis images). Perfusion de fect size by harmonic power Doppler correlated well with residual infarct s ize (r = 0.82, P < 0.01). Conclusions: Myocardial contrast echocardiography using harmonic power Doppler and the new contrast agent SHU 563A accuratel y displays perfusion defects during acute coronary occlusion and after repe rfusion. The site and size of residual myocardial infarction is reliably id entified on line, in color. This approach has excellent potential for clini cal application. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved .