[Polymer microparticles for right and left heart echocardiography and imaging myocardial perfusion after peripheral...

It is conceivable that a stable ultrasound contrast agent could be used for reproducible right and left heart echocardiography and myocardial visualization after intravenous injection. Microparticles from different polymers and preparation procedures were screened in six dogs leading to one superior agent with reproducible high quality echo contrast in doses of 1 mg/kg. This special agent is based on condensates of aspartic acid, ethanolamine and decanoic acid. Out of this material particles were formed with an average diameter of 2 micrometers. The easily suspendable particles were used for the following studies in a dose of 1 mg/kg intravenously in eight pigs. Maximal video intensity averaged 116 +/- 42 relative intensity units (IU) in the right, 137 +/- 42 IU in the left ventricle, 42 +/- 7 in the normally perfused and 11 +/- 2 in the hypoperfused myocardium after circumflex ligature. The area under the intensity curve was 1942 +/- 100 IUxs in the right, 2452 +/- 1291 IUxs in the left ventricle, 518 +/- 124 in the normally perfused and 202 +/- 94 in the hypoperfused myocardium after circumflex ligature. There was no change of heart rate, central arterial or pulmonary artery pressure during and after the injections. There was also no loss of echo intensity during the passage of contrast material through the heart due to systolic pressure. The described agent can be used for the opacification and ultrasonic visualization of the right and left heart as well as normally and hypoperfused myocardium without visible side-effects in animal studies.