Autonomic function is impaired in elderly stroke survivors

Abstract

Background and Purpose - Impaired autonomic function is common in the acute poststroke phase but little is known about the longer term effects, particularly in older people. We sought to determine if autonomic function is impaired after stroke recovery in older patients. Methods - A cross-sectional case-control study comparing autonomic function in 76 nondemented stroke patients with 70 community-living controls aged older than 75 years. Results - Cases were assessed on average 9 months after stroke. From power spectral analysis of heart rate variability, stroke patients had lower total (P=0.032) and low-frequency (P=0.014) spectral densities and impaired baroreflex sensitivity (a low-frequency baroreflex sensitivity, P=0.006). From a series of cardiovascular autonomic reflex tests, heart rate variation during forced respiration, Valsalva ratio, and blood pressure overshoot during Valsalva maneuver were significantly lower in stroke patients (P=0.003, <0.001, and 0.027, respectively). Blood pressure response to isometric exercise was significantly exaggerated in stroke patients (P=0.007). Conclusions - Cardiovascular autonomic function is impaired long after the index event in stroke survivors. Impaired autonomic function may increase the risk of all-cause mortality and cardiovascular mortality in older stroke survivors. © 2005 American Heart Association, Inc.