3-DIMENSIONAL MYOCARDIAL CONTRAST ECHOCARDIOGRAPHY - VALIDATION OF IN-VIVO RISK AND INFARCT VOLUMES

Objectives. The aim of this study was to determine whether three dimen sional (3D) myocardial contrast echocardiography (MCE) could provide a n accurate in vivo assessment of risk and infarct volumes, Background, MCE has been shown to accurately define risk area and infarct size in single tomographic slices, The ability of this technique to measure r isk and infarct volumes by using three-dimensional echocardiography (3 DE) has not been determined, Methods. Fifteen open chest dogs underwen t variable durations of coronary artery occlusion followed by reperfus ion, At each stage, MCE was performed by using left atrial injection o f AIP2O1, a deposit microbubble with a mean diameter of 10 +/- 4 mu m and a mean concentration of 1.5.10(7).ml(-1). Images were obtained ove r a 180 degrees are with use of an automated rotational device and wer e stored in computer as a 3D data set. Postmortem risk area and infarc t size were measured in six to eight left ventricular short axis slice s of equal thickness using technetium-99m autoradiography and tissue s taining, respectively, MCE images corresponding to these planes were r econstructed off-line, Results, A close linear relation was noted betw een the volume of myocardium not showing contrast enhancement on 3D MC E during coronary occlusion and postmortem risk volume (y = 1.2x - 3.0 , r = 0.83, SEE = 5.1, n = 15), The volume of myocardium not showing c ontrast enhancement on 3D MCE after reperfusion also closely correlate d with postmortem infarct volume (y = 1.1x - 3.9, r = 0.88, SEE = 4.8, n = 11), No changes in systemic hemodynamic variables were noted with injections of AIP201. Conclusions. When combined with AIP201, a depos it microbubble, 3D MCE can be used to accurately determine both risk a nd infarct volumes in vivo. This method could be used to assess the ef fects of interventions that attempt to alter the infarct/risk volume r atio. (C) 1997 by the American College of Cardiology.