Assessment of myocardial perfusion by myocardial contrast echocardiography using 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 assessment of myocardial perfusion by contrast echocardiography. In this study, we examined whether myocardial contrast echocardiography using harmonic power Doppler and the new transvenous contrast agent SHU 563A can identify myocardial perfusion defects during coronary occlusion and reperfusion. METHODS: 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. After transvenous administration of SHU 563A, an air-filled, polymeric contrast agent, myocardial contrast echocardiography was performed in short and long axis views with triggered harmonic power Doppler imaging after coronary occlusion and reperfusion. Post-mortem triphenyl tetrazolium chloride staining was performed to verify infarction. Harmonic power Doppler and anatomic data were analyzed by independent observers. RESULTS: During coronary occlusion, 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), power Doppler demonstrated perfusion defects in seven dogs: 0-20% (9+/-8%) (short axis view) and 0-48% (13+/-14%) (long axis view). Five dogs showed anatomic infarction. The anatomic infarct area was 0-18% (6+/-8%) (slices corresponding to the echocardiographic short axis images). Perfusion defect size by harmonic power Doppler correlated well with residual infarct size (r=0.82, P<0.01). CONCLUSIONS: Myocardial contrast echocardiography using harmonic power Doppler and the new contrast agent SHU 563A accurately displays perfusion defects during acute coronary occlusion and after reperfusion. The site and size of residual myocardial infarction is reliably identified on line, in color. This approach has excellent potential for clinical application.

Radiation-associated valvular heart disease in Hodgkin's disease is associated with characteristic thickening and fibrosis of the aortic-mitral curtain.

Radiation-associated valvular dysfunction is characterized by variable aortic and mitral valve thickening. A review of three patients assessed echocardiographically revealed that radiation-associated valvular dysfunction after radiation treatment for Hodgkin's disease may be characterized by a unique and consistent pattern of thickening of the aortic and mitral valves involving the aortic-mitral curtain.

[Myocardial contrast echocardiography with harmonic power Doppler and lung traversing SHU 563A ultrasound contrast medium for imaging myocardial perfusion disorders]. / Myokardiale Kontrastechokardiografie mit harmonischem Power Doppler Verfahren und dem lungengängigen Ultraschallkontrastmittel SHU 563A zur Darstellung von myokardialen Perfusionsstörungen. Tierexperimentelle Untersuchungen bei akuter Ischämie und nach Reperfusion.

The current approach for the assessment of myocardial perfusion using contrast echocardiography involves black-and-white gray scale imaging in b-mode. For better appreciation of perfusion abnormalities, off-line postprocessing techniques including color encoding are used. In this study, we examined whether we could exploit the contrast microbubble response to high ultrasound amplitude--the phenomenon of stimulated acoustic emission--that could be recorded with harmonic power Doppler (HPD) in color to identify myocardial perfusion defects. To assess the potential of HPD, we occluded branches of the left coronary artery for 2-3 h followed by 1 h reperfusion in 10 dogs. After transvenous administration of the new air-filled contrast agent SHU 563A, echocardiographic imaging was performed with ECG-triggered harmonic b-mode (HBM) and the harmonic power Doppler (HPD) approach in different short (SAX) and long axis (LAX) views. Post-mortem TTC staining was performed to verify infarction. HBM, HPD and TTC data were analyzed by independent observers. During coronary occlusion, HPD with SHU 563A showed perfusion defects in 10 dogs in all SAX and LAX views. HBM demonstrated perfusion defects in all dogs in SAX and in 8 dogs in LAX. The correlation of perfusion defect size between HPD and HBM images was good (SAX: r = 0.9, p < 0.001, LAX: r = 0.7, p < 0.01). One hour after reperfusion, both HPD and HBM showed perfusion defects with SHU 563A in 7 dogs. Five dogs showed TTC evidence of infarction. Perfusion defect size by HPD correlated well with residual infarct size (r = 0.8, p < 0.01), while defect size by HBM showed poor correlation (r = 0.3, p = ns). Myocardial contrast echocardiography with HPD and contrast agent SHU 563A identifies perfusion defects in acute coronary occlusion as reliably as HBM. After reperfusion HPD and SHU 563A accurately portray the site and size of residual myocardial infarction on line, in color. This approach has excellent potential for clinical application.