Sympathetic and reflex abnormalities in heart failure secondary to ischaemic or idiopathic dilated cardiomyopathy

Congestive heart failure (CHF) is characterized by a sympathetic activation and a baroreflex impairment whose degree is directly related to the clinic al severity of the disease. However, whether these abnormalities vary accor ding to the ischaemic or idiopathic dilated nature of the CHF state has not been conclusively documented. In patients with a clinically stable, chroni c CHF state in New York Heart Association functional class II and III, due either to ischaemic heart disease (IHD; n = 22, age 60.3 +/-2.4 years, mean s +/-S.E.M.) or to idiopathic dilated cardiomyopathy (IDC; n = 20, age 58.9 +/-2.8 years), and in 30 age-matched controls, we measured arterial blood pressure (using a Finapres device), heart rate (by electrocardiogram) and p ostganglionic muscle sympathetic nerve traffic (by microneurography) at res t and during baroreceptor manipulation induced by the vasoactive drug-infus ion technique. Blood pressure values were not significantly different in CH F patients and controls. Compared with controls, heart rate was similarly i ncreased and left ventricular ejection fraction (by echocardiography) simil arly reduced in CHF patients with IHD or IDC. Muscle sympathetic nerve traf fic was significantly greater in CHF patients than in controls, and did not differ between patients with IHD or IDC (67.3 +/-4.2 and 67.8 +/-3.8 burst s/100 heart beats respectively). This was also the case for the degree of b aroreflex impairment. These data show that CHF states due to IHD or to IDC are characterized by a similar degree of peripheral sympathetic activation and by a similar impairment of the baroreflex function. Thus the neuroadren ergic and reflex abnormalities characterizing CHF are independent of its ae tiology.