Concomitant hemodynamic effects of intracoronary injections of a new transpulmonary contrast medium

A new transpulmonary echo contrast agent (SH U 508) was injected intracoronally to six anaesthetised sheep to examine its possible direct cardiac effects. SH U 508 was injected in randomised order in three different volumes (2, 4 and 8 ml; n = 12, 10, 9) with the same drug concentration of 200 mg/ml. The 2 ml and 4 ml injections had no relevant effect on the arterial, pulmonary-arterial and ventricular pressures, on the left ventricular contraction velocity and on the myocardial blood flow (less than +/- 10% of the control value). The left ventricular relaxation velocity decreased by 20%. The disturbance of the left ventricular relaxation at a volume of 8 ml was pronounced (about 40% decrease). Slight left ventricular dysfunction further manifested itself in a decreased systolic pressure (-15%) and increased left ventricular enddiastolic pressure (20%). In summary the overall effect of the intracoronary injections of SH U 508 exhibited only minor cardiac side effects. If the current results are extrapolated to peripheral-venous application, the clinically required central-venous 8 ml injection of a 400 mg/ml suspension is not expected to produce any coronary haemodynamic side effects, due to drug dilution in the pulmonary circulation and resulting low intra-coronary concentrations.