Persistent opacification of the left ventricle and myocardium with a new echo contrast agent

Echo contrast agents with long survival times open up new fields of applica tion in the investigation of tissue perfusion and cardiovascular function. The purpose of this study was to characterize the time-course of the opacif ication of the heart cavities and myocardium with a new long-lasting second -generation, phopsholipid-based echo contrast agent containing perfluoropen tane (BY963-C5F12), and to compare its contrast potency with that of air-fi lled phospholipid monolayer (BY963-air), Doses of 0.03 mL/kg, 0.08 mL/kg an d 0.16 mL/kg of BY963-air and BY963-C5F12 were administered intravenously t o six conscious dogs weighing 25-36 kg, A transthoracic echocardiography wa s performed to evaluate peak intensity and area under the curve (AUC) from regions-of-interest placed in the right ventricle, left ventricle and left ventricular (LV) myocardium using acoustic densitometry, All injections wer e well tolerated, without wall-motion abnormalities or ECG changes. The LV cavity and myocardium were uniformly and well opacified for both echo contr ast agents. However, at all administered doses, the contrast efficacy and d uration were much more pronounced using BY963-C5F12 than with BY963-air, Fo r the myocardium, the average peak intensity increased from 11.9 +/- 2.8 to 15.0 +/- 2.7 (not significant) following injection of BY963-air and from 1 2,8 +/- 3.2 to 18.7 +/- 2.8 (p < 0.01) following IV administration of BY963 -C5F12; the latter corresponding to an increase in myocardial opacification of 46%, In conclusion, these results show the high myocardial opacificatio n of BY963-C5F12 as compared to BY963-air, The simple incorporation of a pe rfluorocarbon gas into the phopholipid monolayer BY963 instead of air alter s the acoustic properties of this contrast agent, resulting in qualitativel y different application potentials for tissue opacification, (C) 1999 World Federation for Ultrasound in Medicine & Biology.