An abnormal relationship between blood pressure and pulse rate in amyotrophic lateral sclerosis.

Abstract

To clarify the autonomic dysfunctions in amyotrophic lateral sclerosis (ALS) patients, we investigated the relationship between blood pressure (BP) and pulse rate (PR), QTc interval, and coefficient of variation in the R-R interval (CVR-R) in ALS patients. BP and PR were determined automatically every 30 min for 24 h in 6 patients with ALS and in 18 healthy age-matched volunteers. The QTc interval and CVR-R were also evaluated using an electrocardiogram. The relationship between BP and PR was lost in the ALS group. There was no significant difference in the QTc interval or CVR-R between the ALS and control groups. We speculate that the imbalance between BP and PR observed in the ALS group reflects a disorder in the balance between the sympathetic and parasympathetic nervous systems.