Comparison of a new intravenous echo contrast agent (BY 963) with Albunex for opacification of left ventricular cavity.

Transpulmonary echo contrast agents improve the evaluation of left ventricular function by two-dimensional echocardiography due to a better endocardial border delineation. To compare the contrast effect in the right and left ventricular cavities, a new transpulmonary echocontrast agent, BY 963 and Albunex were intravenously administered to five non-anaesthetized dogs. The right and left ventricular echocardiographic image intensities were quantitatively measured at 60 cardiac cycles using a commercially available ultrasound system. BY 963 and Albunex were intravenously administered at three doses: 0.01 ml/Kg, 0.05 ml/Kg and 0.1 ml/Kg. The area under the curve (AUC, intensity units x heart cycles) and peak intensity (Peak I, intensity units) were estimated for the right (RV) and left ventricular (LV) cavities at the mid ventricular level using acoustic intensitometry. BY 963 injection produced the following values: At the dose of 0.01, 0.05 and 0.1 ml/Kg the AUC amounted to 702 +/- 449, 877 +/- 470 and 890 +/- 320 intensity units x heart cycles in RV and to 542 +/- 406, 806 +/- 557 and 721 +/- 392 in LV (LV/RV ratios: 77%, 92% and 81%). Peak I was at the doses 0.01, 0.05 and 0.1 ml/Kg 29 +/- 4.7, 33 +/- 5.2 and 35 +/- 3.2 intensity units in RV and 18 +/- 5.9, 21 +/- 6.2 and 20 +/- 3.3 in LV (LV/RV ratios: 62%, 64% and 57%). Albunex also produced right and left heart opacification values: at the doses 0.01, 0.05 and 0.1 ml/Kg the AUC amounted to 416 +/- 231, 493 +/- 231 and 674 +/- 390 in RV and to 71 +/- 71, 158 +/- 102 and 277 +/- 120 in LV (LV/RV ratios: 17%, 34% and 41%). Peak I was at the doses of 0.01, 0.05 and 0.1 ml/Kg 19 +/- 5.2, 23 +/- 5.4 and 29 +/- 4.1 in RV and 8 +/- 4.8, 13 +/- 4.7 and 17 +/- 3.2 in LV (LV/RV ratios: 42%, 57% and 59%). Intravenous injection of BY 963 leads to complete opacification of the left ventricular cavity and to high AUC values and peak intensity values at all three dosages. The loss of contrast effect from the right to the left ventricular cavity was very low: the LV/RV ratio of BY 963 was higher than that of Albunex. The new transpulmonary echo contrast agent BY 963 promises to be an excellent echo contrast agent for the noninvasive assessment of left ventricular function.