HEART-RATE POWER SPECTRUM ANALYSIS OF AUTONOMIC DYSFUNCTION IN ADOLESCENTS WITH ANOREXIA-NERVOSA

We studied autonomic modulation of heart rate in 8 females with anorex ia nervosa (AN) using power spectral analysis (PSA) of heart rate vari ability in the supine and standing positions at baseline and after 2 w eeks of intensive nutritional rehabilitation, and compared findings wi th healthy female control subjects. The results indicate that there is a decrease in sympathetic modulation of heart rate, evident by a defi cit of low frequency (0.01-0.15 Hz) heart rate power in the supine pos ition in AN compared with control subjects. In addition, parasympathet ic modulation of heart rate failed to decrease with standing. A trend toward improvement in autonomic control of heart rate in adolescents w ith AN occurs in the supine position relatively early in weight rehabi litation. PSA is a sensitive, quantitative, and noninvasive means of d etermining autonomic control of heart rate and could be a useful tool in monitoring the health of patients with AN. (C) 1994 by John Wiley & Sons, Inc.