Effects of short-term administration of dobutamine on left ventricular performance, exercise capacity, norepinephrine levels, and lymphocyte adrenergic receptor density in congestive heart failure

Abstract

This study was designed to determine the feasibility of identifying those patients with chronic heart failure who will be improved by dobutamine infusion. Twenty-two patients with stable heart failure were treated by infusion of an average dobutamine dose of 12.5 ng/kg/min for 36 hours, then again during a 4-hour session once a week for 1 month. Patients were evaluated by clinical, ergometric, and biochemical parameters (plasma norepinephrine and lymphocyte beta-receptor density) before and after every infusion. Hemodynamics were assessed before and during the first dobutamine infusion. A test with isoproterenol was performed prior to the start of dobutamine therapy. All patients exhibited hemodynamic improvement, which peaked at the 12th hour (55% increase in the cardiac index [p<0.01]; 35% reduction in the filling pressure and systemic arterial resistance). Five patients stopped the study prematurely. Nine patients (group 1) were clinically improved according to their NYHA classification. Eight patients (group 2) remained stable or had progressive disease. The lymphocyte beta-receptor density before dobutamine infusion was significantly higher in group 1 than in group 2 (66±12 vs. 46.7±18 fM/mg; p<0.01). Finally, a good correlation (p<0.05) was observed between the beta-receptor level and the isoproterenol dose required to obtain a heart rate of 130 beats/min.