DECREASED HEART-RATE-VARIABILITY IN AMYOTROPHIC-LATERAL-SCLEROSIS

Autoregressive spectral analysis of heart rate variability (HRV) was p erformed in 29 patients with amyotrophic lateral sclerosis (ALS) and 3 3 age-matched healthy subjects to evaluate the involvement of the auto nomic nervous system. HRV analysis provides a means to recognize low ( LF) and high (HF) frequency components, respectively mediated by sympa thetic and parasympathetic heart control. An increase in the mean hear t rate at rest (P < 0.001), a decrease in standard deviation of R-R in terval as well as in PNN50 (P < 0.001), and an increase in the LF/HF c omponent ratio (P < 0.01) were found in the ALS patients, indicating a vagal-sympathetic imbalance. These alterations were not related to th e clinical features and to the duration of the disease. Our results su ggest a subclinical involvement of the autonomic nervous system in ALS , particularly affecting parasympathetic cardiovascular control. (C) 1 995 John Wiley & Sons, Inc.