Dobutamine potentiates the peripheral chemoreflex in patients with congestive heart failure

Abstract

Backgroundβ-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. MethodsWe 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. ResultsDobutamine 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). ConclusionsDobutamine 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.