The role of endogenous dopamine in congestive heart failure

Although the effects of epinephrine and norepinephrine in congestive heart failure have been extensively studied, and exogenous dopamine, another of the catecholamines, has been widely used for the treatment of congestive heart failure, little attention has been paid to the physiological significance of endogenous dopamine in this condition. The present study was therefore designed to assess the physiological significance of endogenous dopamine in congestive heart failure. Nineteen patients with congestive heart failure caused by such conditions as acute myocardial infarction, valvular disease and dilated cardiomyopathy were examined before and after treatment with diuretics, digitalis and vasodilators. Electrolyte, creatinine and catecholamine concentrations in plasma and urine were analyzed. Urinary dopamine levels were increased in 13 out of 19 cases before treatment and returned to the normal range after treatment, falling from 2448 +/- 950.7 to 528.8 +/- 56.3 micrograms/day (normal level, less than 700 micrograms/day). Urinary dopamine excretion was markedly elevated within 24 hours after the onset of symptoms of heart failure, such as chest pain, palpitations and dyspnea. The relationship between urinary dopamine excretion and time after the onset of symptoms showed a strong statistical correlation (r = 0.55, p less than 0.001). Urinary dopamine excretion was also well correlated with plasma dopamine concentration, urinary norepinephrine excretion and venous pressure. From these results, it is concluded that endogenous dopamine seems to play an important role during the acute phase of congestive heart failure.