Acute inotropic stimulation with dopamine in severe congestive heart failure: Beneficial hemodynamic effect at rest but not during maximal exercise

Abstract

Hemodynamic and metabolic effects of dopamine were studied at rest and during maximal exercise in 13 patients with severe chronic congestive heart failure (CHF). During exercise before the administration of dopamine, the stroke volume index increased from 17.1 ± 5.2 ml/m 2 at rest to 28.1 ± 10.9 ml/m 2 (p < 0.001) at exhaustion, while pulmonary capillary wedge (PCW) pressure increased from 22.7 ± 12.7 to 43.9 ± 11.9 mm Hg (p < 0.001). The arteriovenous oxygen difference increased from 8.9 ± 2.3 ml/100 ml to 12.4 ± 2.0 ml/100 ml (p < 0.001) and oxygen uptake increased from 3.5 ± 0.6 to 11.9 ± 2.5 ml/kg/min (p < 0.001). At rest, dopamine increased the stroke volume index to 23.3 ± 8.1 ml/m 2 (p < 0.001) and reduced the PCW pressure to 20.5 ± 1.1 mm Hg (p < 0.05). However, during maximal exercise, the stroke volume index and PCW pressure were not changed by dopamine: 28.1 ± 10.9 versus 28.6 ± 10.2 ml/m 2 (difference not significant [NS]) and 43.9 ± 11.9 versus 42.5 ± 11.2 mm Hg (NS), respectively. In contrast, the maximal heart rate achieved during exercise was significantly higher with dopamine, 140.3 ± 29.3 versus 136.0 ± 29.7 beats/min (p < 0.05), which contributed to a slight augmentation in the maximal cardiac index, 3.82 ± 1.13 versus 3.64 ± 1.17 liters/min/m 2 (p < 0.05). Nonetheless, neither peak arteriovenous oxygen difference nor maximal oxygen uptake were significantly changed by dopamine. Thus, administration of dopamine to patients with severe chronic congestive heart failure appears to exert a slight chronotropic effect, but does not improve ventricular performance during maximal exercise.