CARDIAC NEUROPEPTIDE-Y AND NORADRENALINE BALANCE IN PATIENTS WITH CONGESTIVE-HEART-FAILURE

Objective-To measure plasma concentrations of noradrenaline and neurop eptide Y-like immunoreactivity in relation to cardiac function in pati ents with congestive heart failure. Design-Retrospective analysis of p lasma noradrenaline concentrations and neuropeptide Y-like immunoreact ivity in the arterial and coronary circulations, in patients with a hi gh or low ejection fraction (31.3% (1.3%) or 17.7% (1.1%) respectively ) and in healthy volunteers. Setting-Cardiology department of a univer sity hospital. Patients-41 patients with congestive heart failure with various aetiologies. Ten healthy volunteers sewed as a reference grou p. Main outcome measures-Concentrations of noradrenaline measured by h igh performance liquid chromatography and of neuropeptide Y-like immun oreactivity measured by radioimmunoassay. Cardiac index, pulmonary cap illary wedge pressure, pulmonary vascular resistance, and systemic vas cular resistance were derived by catheterisation of the right heart. E jection fraction was measured by radionuclide angiography, cineangiogr aphy, or M mode echocardiography. Results-There were pronounced and si gnificant increases in circulating arterial concentrations of neuropep tide Y-like immunoreactivity and noradrenaline in both the high and lo w ejection fraction groups compared with the healthy subjects. In the patients myocardial release of neuropeptide Y-like immunoreactivity te nded to be greater compared with normal subjects, but not significantl y so. While normal subjects showed myocardial noradrenaline uptake, pa tients with congestive heart failure showed significant and progressiv e myocardial noradrenaline release. Arterial as well as coronary sinus concentrations of neuropeptide Y-like immunoreactivity correlated sig nificantly with plasma noradrenaline concentrations from the respectiv e sites. Plasma noradrenaline concentrations in the artery and coronar y sinus were negatively correlated with ejection fraction and cardiac index; no such relations were found for concentrations of neuropeptide Y-like immunoreactivity. Conclusions-Both circulating concentrations of neuropeptide Y-Like immunoreactivity and noradrenaline are signific antly increased in moderate to severe forms of congestive heart failur e. Plasma concentrations of neuropeptide Y-like immunoreactivity corre lated with plasma noradrenaline concentrations, but plasma noradrenali ne concentrations alone correlated with ejection fraction and cardiac index. Thus plasma noradrenaline concentration seems to be a more sens itive index of cardiac dysfunction than the concentration of neuropept ide Y-like immunoreactivity in congestive heart failure.