HARMONIC POWER DOPPLER CONTRAST ECHOCARDIOGRAPHY - PRELIMINARY CLINICAL-RESULTS

Background: In fundamental and second harmonic echocardiography new co ntrast media opacify the cavities and reduce the difference in the gra y level between the cavity and the myocardium thus obscuring the borde rs of the myocardium. Objectives: The aim of the study was to examine the potential usefulness of second harmonic power Doppler imaging (HPD ) in providing adequate delineation of the myocardium from the Left ve ntricular (LV) and right ventricular (RV) cavities during intravenous contrast echocardiography. Using HPD, microbubbles in a cavity or a ti ssue are imaged as colored pixels superimposed on a conventional B-sca n image. Methods: In a pilot study, three healthy volunteers and two p atients with ischemic heart disease were investigated using an ATL-HDI 3000 echo system. Four chamber views were obtained using fundamental B-scan, harmonic B-scan two-dimensional echocardiography (H2D) and HPD following intravenous injections of 3 g Levovist(R). Results: Using i ntermittent scanning/recording, H2D and HPD provided intensive and hom ogenous contrast effects in the RV and LV cavities. Good delineation o f the myocardium was found in all subjects using HPD, whereas in two o f three volunteers and in one of two patients ventricular septal and a pical endocardial borders were obscured during H2D. No obvious change in myocardial backscatter was visually found with H2D. However, in all three healthy volunteers and in one of two patients, HPD recordings d emonstrated patchy and reticular patterns in the myocardium, which wer e different from the homogenous signals in the LV cavity. These are co nsistent with imaging of intramyocardial coronary vessels. Conclusions : HPD with intravenous Levovist is feasible. This technique demonstrat ed good delineation of ventricular cavities from the myocardium as wel l as presence of visible contrast in the myocardium. This pilot study justifies further clinical trials to evaluate the clinical benefit of this approach.