Beneficial haemodynamic effects of intravenous dopexamine in patients with low-output heart failure.

Dopexamine is a novel compound that has DA1-dopaminergic and beta 2-adrenergic agonist properties capable of producing beneficial systemic and renal vasodilation. The acute haemodynamic effects in 10 patients with low-output-state ischaemic cardiac failure (NYHA IV) were recorded before (control) and during graded incremental doses of dopexamine infusion from 0.5 to 6.0 micrograms/kg/min. Dopexamine produced a marked increase in cardiac index from 1.6 +/- 0.2 (control) to a maximum of 2.8 +/- 0.4 L/min/m2 (p less than 0.001) primarily by inducing vasodilation, with reduction in systemic vascular resistance from 1,720 +/- 136 (control) to 1,116 +/- 136 dynes.s.cm-5 (p less than 0.05). Using a more sophisticated analytical technique which enables us to separate direct inotropic from vasodilatory effects, we were able to identify, in eight of the patients, a direct dopexamine-induced positive inotropism. These beneficial central haemodynamic effects of dopexamine, when coupled with its known DA1-dopaminergic agonist property, indicate that dopexamine may have a place in the management of patients in severe heart failure.