Dobutamine Potentiates the Peripheral Chemoreflex in Patients With Congestive Heart Failure

Background: β-Adrenergic agonists may increase chemoreflex sensitivity to hypoxia in normal humans. Chemoreflex function is important in the pathophysiology of heart failure. Whether the β-1 agonist dobutamine, which is frequently administered to patients with heart failure, alters their chemoreflex sensitivity is not known. Methods: We tested the hypothesis that dobutamine increases chemoreflex sensitivity in patients with congestive heart failure (CHF) using a randomized, double-blinded, placebo-controlled study design. We assessed the influence of dobutamine on minute ventilation and hemodynamics during normoxic breathing and during peripheral chemoreflex deactivation by hyperoxia (100% O₂) in 9 patients with CHF. Results: Dobutamine increased minute ventilation in patients with CHF (9.4 ± 0.9 versus 8.4 ± 0.7 L/min, P = .005) during normoxia. Peripheral chemoreflex deactivation by hyperoxia suppressed the ventilatory effects of dobutamine (10.4 ± 1.4 L/min for dobutamine versus 10.0 ± 1.2 L/min for placebo, P = .34). Conclusions: Dobutamine increases ventilation during normoxia, but not during hyperoxia in patients with CHF. We conclude that dobutamine enhances peripheral chemoreflex sensitivity in patients with congestive heart failure.