Left heart opacification with peripheral venous injection of a new saccharide echo contrast agent in dogs

AbstractOpacification of the left heart chambers after venous injection of echo contrast agents with transpulmonary capabilities has been difficult to achieve because of a lack of availability of a biodegradable nontoxic agent that produces uniformly small microbubbles. SHU-508 is a new saccharide echo contrast agent that produces bubble sizes from 2 to 8 μm in diameter, capable of traversing the pulmonary capillary bed and resulting in left heart contrast. The echo intensity produced by this agent was compared with that of agitated saline solution, indocyanine green and SHU-454 (another experimental saccharide agent for right-sided contrast) during 136 injections in eight dogs. Videotaped two-dimensional echographic images were digitized and analyzed with the use of videodensitometry for peak right and left ventricular intensity, pulmonary transit times and time of persistence of contrast. The highest right ventricular intensity value (3,594 ± 1,393) was achieved with SHU-508 (p < 0.05 compared with the other agents). The right ventricular contrast seen with SHU-508 also persisted for a longer period (22.8 ± 12 s) than with the standard agents (p < 0.001).Left ventricular contrast with SHU-508 was visually evident in all 42 injections, whereas the peak left ventricular intensity was 35% as bright as that produced in the right ventricle by the same agent. Peak left ventricular intensity values from SHU-508 were compared with those from agitated saline solution injected from the pulmonary capillary wedge position in four dogs. SHU-508 produced brighter left ventricular intensity (1,281 ± 607) compared with that obtained with the saline-wedge technique (p < 0.002). The left ventricular echo contrast effect persisted for 18.8 ± 6 s compared with 8.6 ± 2 s for saline solution (p < 0.001). The pulmonary transit time for SHU-508 was 10.1 ± 5 s for the group and appeared to vary depending on individual heart rates.Thus, SHU-508 is a new saccharide echo contrast agent that produces effective opacification of the left ventricular cavity after peripheral venous injection in dogs