Effects of dobutamine and salbutamol on haemodynamics and atrial natriuretic factor in patients with severe congestive heart failure.

The influence of two cardiac inotropic drugs, dobutamine and salbutamol, on plasma atrial natriuretic factor (ANF) was investigated in 20 patients with congestive heart failure. All were in New York Heart Association class-III or IV. The patients underwent right heart catheterization with determination of central pressures, cardiac output, and pulmonary arterial plasma ANF during incremental infusions with dobutamine or salbutamol. Fourteen patients completed the study. Both drugs induced comparable increases in cardiac index and decreases in total systemic vascular resistance (P less than 0.01) without significant changes in central pressures. Heart rate rose after salbutamol (P less than 0.05), but not after dobutamine. No changes in plasma ANF were observed after either of the drug infusions. ANF secretion rate was calculated from simultaneous measurements of ANF in right atrial and pulmonary arterial plasma before and after salbutamol infusion, and median values rose more than seven-fold (P less than 0.05). The results demonstrate that ANF secretion rate is augmented after beta-adrenergic agents, possibly by a direct beta 2-adrenergic stimulation, in patients with severe congestive heart failure, and that changes in plasma ANF are an insufficient measure of ANF release when patient samples are small.