955-58 Intracardiac Echocardiographic Quantification and Monitoring of Myocardial Perfusion Defects and Reperfusion with the Use of Intravenous Injection of FS069, a Transpulmonic Contrast Agent

Abstract

Despite major efforts, echocardiographic delineation of LV myocardial hypoperfusion with intravenously (IV) injected contrast remains difficult because of the lack of an ideal agent. and problems in resolution of transthoracic 2DE images. In this study, we explored the potential of 2 new approaches: 1) a new IV contrast agent, FS069 (MBI) that can cross the pulmonary circulation and 2) Intracardiac echocardiography (ICE) that can depict LV myocardium crisply. In 5 anesthetized dogs, ICE was performed using a 6 Fr, 12.5 MHz catheter within the LV. Once short-axis views were obtained, a small dose (0.3 mg) of FS069 was injected into the femoral vein at baseline, following occlusion of the LAD, PDA, and OM coronary arteries, and after reperfusion. Continuous ICE monitoring was performed. Perfusion defects, quantified and expressed as % of LV, were correlated with the extent of regional wall motion abnormalities (WMA) measured in ICE images without contrast. After IV injection, the RV cavity was opacified, followed by the LV cavity. All endocardial borders were well defined. Contrast enhancement was noted within the myocardium within 5 beats of LV cavity opacification. During 18 episodes of ischemia we produced, opacification of the LV cavity facilitated identification of WMA in all. Perfusion defects corresponding to WMAs were observed in all cases where WMAs were present; however 2 episodes of ischemia were not accompanied by either contrast defects or WMA. Defects were visible long enough for ICE to image the LV at multiple levels. Following reperfusion and re-injection of contrast, no defects were noted. The perfusion defects ranged from 13–62% (mean 37.6 ± 14.8) of the total LV; the extent of WMA was 14–66% (mean 39.0 ± 15.2) of the LV circumference. Defect size (x) correlated well with extent of WMA (y), with y = 0.98x + 2.1, r = 0.95. P < 0.001. (1) IV injection of FS069 is sensitive and strong enough to demonstrate myocardial perfusion and ischemia that can be quantified by ICE; (2) Contrast changes persist long enough to image all levels of the LV by ICE; (3) Catheter-based imaging, when refined. could be useful for monitoring ischemia and perfusion status.