Usefulness of power Doppler contrast echocardiography to identify reperfusion after acute myocardial infarction

Microvascular integrity, as seen by myocardial contrast echocardiogrophy (M CE), assesses whether myocardium has been successfully reperfused after on acute myocardial infarction. Until now this has been demonstrated only with intracoronary injection of an ultrasound contrast agent. Power Doppler ima ging is a recently developed myocardial contrast echocardiographic method t hat counts the contrast microbubbles destroyed by ultrasounds and displays this number in color. This study sought to evaluate whether power Doppler M CE is able to visualize myocardial reperfusion during intravenous contrast injection. Thirty patients were evaluated 2 days after their first myocardi al infarction during intravenous infusion of perfluorocarbon-exposed sonica ted dextrose albumin (PESDA). Coronary artery angiography and single-photon emission computed tomography (SPECT) were used as reference techniques. A 16-segment left ventricular model was used to relate perfusion to coronary artery territories. Sensitivity and specificity of power Doppler MCE for se gments supplied by infarct-related arteries were 82% and 95%, respectively. Accuracy of power Doppler MCE and SPECT were similar (90% vs 92% on segmen tal basis and 98% vs 98% on coronary artery territory basis). Two-dimension al echocardiography was repeated after 6 weeks. Segments recovering wall mo tion after 6 weeks were defined as stunning myocardium. Dysfunctional but p erfused myocardium at day 2 after the infarctian showed a better late recov ery of wall motion compared with dysfunctional but nonperfused myocardium ( p < 0.001). In conclusion, harmonic power Doppler imaging is a sensitive an d specific method for the identification of myocardial reperfusion early af ter myocardial infarction. It yields prognostic information for late recove ry of ventricular function differentiating stunning (dysfunctional but perf used) from necrotic myocardium (dysfunctional and nonperfused). (C) 2001 by Excerpta Medica, Inc.