SUMMARY Plasma concentrations of cyclic nucleotides (adenosine monophosphate (AMP) and guanosine monophosphate (GMP) were measured by an ultrasensitive radioimmunoassay in 138 patients with heart failure due to various causes. Measurements were related to the New York Heart Association classification of symptoms, plasma noradrenaline concentrations, and mean pulmonary artery pressures. Serial concentrations of cyclic AMP and GMP were also measured daily in four patients treated for acute left ventricular failure. Plasma concentrations of cycle AMP were related to the severity of the heart failure, plasma noradrenaline concentrations, and pulmonary artery pressures. Cyclic AMP concentrations fell rapidly after treatment of acute left ventricular failure. Plasma concentrations of cyclic GMP also depended on the severity of heart failure and the pulmonary artery pressure, and decreased sharply with treatment although remaining at a high value. The cyclic GMP concentrations were significantly higher in patients with mitral stenosis than in those with other types of heart failure.It is well known that sympathetic nervous activity increases in patients with congestive heart failure. Chidsey et al reported that urinary excretion of noradrenaline was increased in heart failure.1 Studies by Thomas and Marks2 and ourselves3 showed that the plasma concentration of noradrenaline increased in patients with congestive heart failure, suggesting that the sympathetic nervous activity of these patients is increased. On the other hand, Eckberg et al found that the parasympathetic influence on sinoatrial node automaticity as determined by vagal blockade with atropine was reduced in patients with heart failure.4 They also reported that baroceptor-induced slowing of the heart rate provoked by phenylephrine was appreciably reduced in patients with heart disease.4With cyclic adenosine monophosphate (AMP), which is the second messenger for beta adrenergic agents and many hormones, the plasma concentration appears to reflect the changes in tissue5 since the nucleotide in plasma is in a dynamic steady state relation with its intracellular pools.6 Cyclic guanosine monophosphate (GMP), like cyclic AMP, is present in plasma,7 and its_plasma concentration cyclic AMP Requests for reprints to Dr K Ogawa, 2nd Department of Internal Medicine, Nagoya University School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466, Japan.Accepted for publication 26 January 1984 could serve as an index for cholinergic activity.8 In the present study, therefore, the plasma concentrations of noradrenaline, cyclic AMP, and cyclic GMP were measured simultaneously in patients with congestive heart failure.
Patients and methodsEighty five normal subjects (54 men and 31 women, mean age 47 years) and 138 patients with congestive heart failure were studied. The latter group comprised 41 patients with ischaemic heart disease, 40 with valvular heart disease, 13 with hypertensive heart disease, 13 with cor pulmonale, 10 with cardiomyopathy, five with myocarditis, five wi...