Central and renal hemodynamic effects of a new agonist at peripheral dopamine- and beta-2 adrenoreceptors (dopexamine) in patients with heart failure.

The effect of dopexamine, a new dopamine analogue, on central and renal hemodynamics was evaluated in nine patients with chronic, congestive heart failure caused by severe left ventricular (LV) systolic dysfunction. The administration of the maximally tolerated dose (7.2 +/- 4 micrograms/kg/min) resulted in a significant increase in cardiac index from 1.9 +/- 0.4 L/min/m2 to 2.6 +/- 0.9 L/min/m2 (p less than 0.05). This increase in cardiac index was largely a result of increase in heart rate (from 88 +/- 20 beats/min to 104 +/- 24 beats/min, p less than 0.05), because stroke volume index demonstrated only a small change (from 23 +/- 10 ml/m2 to 27 +/- 11 ml/m2, p not significant) in spite of a significant fall in systemic vascular resistance from 1992 +/- 717 dynes.sec.cm-5 to 1361 +/- 524 dynes.sec.cm-5 (p less than 0.05) and diastolic blood pressure (from 89 +/- 15 mm Hg to 80 +/- 17 mm Hg, p less than 0.05). No change was seen during dopexamine infusion in systolic blood pressure, right and left ventricular filling pressures, and LV stroke work index. Both renal blood flow and glomerular filtration rate were impaired at baseline in most patients. Dopexamine administration resulted in a significant increase (2x coefficient of variation) in renal blood flow in two patients only. Mean values of both renal blood flow and glomerular filtration rate did not show significant change (485 +/- 183 ml/min vs 563 +/- 221 ml/min and 89 +/- 39 ml/min vs 93 +/- 34 ml/min, respectively, p not significant).(ABSTRACT TRUNCATED AT 250 WORDS)