764-6 Effect of a New Phase Shift Echo Contrast Agent on Myocardial Blood Flow and Hemodynamics

We have demonstrated the accuracy of myocardial area at risk and infarct size determinations with an emulsion of dodecafluoropentane (EchoGen = EG) which is liquid at room temperature and a gas at body temperature (AHA meeting). To determine the effect of EG on myocardial blood flow (MBF), 10 fully anesthetized dogs received 4 (30 min apart) or 8 (10 min apart) peripheral intravenous injections of EG 0.5 ml/kg. HR, BP, T, PAP, PCWP, and CO were monitored. MBF was assessed with radiolabeled microspheres. Echo images were recorded with TEE. MBF (ml/min/g, ± SEM) was determined in four slices of the left ventricle (LV). Serial assessments of LV wall motion were performed. MBF base MBF final Anterior wall 1.4 ± 0.05 1.2 ± 0.2 Septal wall 1.2 ± 02 1.2 ± 0.2 Lateral wall 1.5 ± 0.1 1.2 ± 0.2 Posterior wall 1.5 ± 0.2 1.2 ± 0.2 PCWP, CO, and MBF were unchanged following 4 doses of EG. Systemic hypotension was seen, similar to that observed during administration of other perfluorochemicals in dogs. Pulmonary hypertension and deterioration in LV function were seen with 8 doses at 10 min intervals (cumulative dose: 4.0 ml/kg). Conclusion Administration of EG at frequent intervals can lead to a significant increase in PAP and myocardial dysfunction. However, EG does not produce significant alteration of MBF or PAP when administered at 30 min intervals at dosages that permit determination of myocardial area at risk and infarct size in our canine preparation.