The effects of dobutamine on renal sympathetic activity in human heart failure.

The pathophysiology of the cardiorenal syndrome remains poorly understood. Renal sympathetic activity is increased in heart failure. It contributes to the sodium avid state, renal vasoconstriction, and reduced glomerular filtration rate that is characteristic of a large number of heart failure patients. Dobutamine is commonly used in the treatment of decompensated heart failure. We used the norepinephrine spillover technique to examine the effects of dobutamine on renal sympathetic activity in human heart failure. Dobutamine was titrated to increase the peak positive rate of change in left ventricular pressure by 25%. In 11 patients with heart failure, dobutamine infusion reduced efferent renal sympathetic activity by 50% (P < 0.003). This sympatholytic response was associated with an 11% increase in renal plasma flow (P < 0.03) and a 12% increase in glomerular filtration rate (P < 0.04). These findings suggest that dobutamine infusion is acutely associated with a beneficial effect on renal function. This observation is potentially related to a renal sympatholytic response to ventricular mechanoreceptor activation associated with the inotropic effects of beta-adrenergic receptor stimulation.