title: Changes of deceleration and acceleration capacity of heart rate in patients with acute hemispheric ischemic stroke.
abstract: OBJECTIVE
  Autonomic dysfunction is common after stroke, which is correlated with unfavorable outcome. Phase-rectified signal averaging is a newly developed technique for assessing cardiac autonomic function, by detecting sympathetic and vagal nerve activity separately through calculating acceleration capacity (AC) and deceleration capacity (DC) of heart rate. In this study, we used this technique for the first time to investigate the cardiac autonomic function of patients with acute hemispheric ischemic stroke.
  
  
  METHODS
  A 24-hour Holter monitoring was performed in 63 patients with first-ever acute ischemic stroke in hemisphere and sinus rhythm, as well as in 50 controls with high risk of stroke. DC, AC, heart rate variability parameters, standard deviation of all normal-to-normal intervals (SDNN), and square root of the mean of the sum of the squares of differences between adjacent normal-to-normal intervals (RMSSD) were calculated. The National Institutes of Health Stroke Scale (NIHSS) was used to assess the severity of stroke. We analyzed the changes of DC, AC, SDNN, and RMSSD and also studied the correlations between these parameters and NIHSS scores.
  
  
  RESULTS
  The R-R (R wave to R wave on electrocardiogram) intervals, DC, AC, and SDNN in the cerebral infarction group were lower than those in controls (P=0.003, P=0.002, P=0.006, and P=0.043), but the difference of RMSSD and the D-value and ratio between absolute value of AC (|AC|) and DC were not statistically significant compared with those in controls. The DC of the infarction group was significantly correlated with |AC|, SDNN, and RMSSD (r=0.857, r=0.619, and r=0.358; P=0.000, P=0.000, and P=0.004). Correlation analysis also showed that DC, |AC|, and SDNN were negatively correlated with NIHSS scores (r=-0.279, r=-0.266, and r=-0.319; P=0.027, P=0.035, and P=0.011).
  
  
  CONCLUSIONS
  Both DC and AC of heart rate decreased in patients with hemispheric infarction, reflecting a decrease in both vagal and sympathetic modulation. Both DC and AC were correlated with the severity of stroke.
authors.affiliation: Department of Neurology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China.
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Xu
authors.affiliation: Department of Cardiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China.
authors.forename: Xing-De
authors.initials: XD
authors.lastname: Wang
authors.affiliation: Department of Neurology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China.
authors.forename: Jia-Jun
authors.initials: JJ
authors.lastname: Yang
authors.affiliation: Department of Cardiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Department of Neurology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China.
authors.forename: Yong-Chao
authors.initials: YC
authors.lastname: Pan
mesh_terms: D000054:Acceleration; D000368:Aged; D000369:Aged, 80 and over; D001341:Autonomic Nervous System / Q000503:physiopathology*; D003654:Deceleration; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000503:physiopathology*; D014481:United States
keywords: acceleration capacity of heart rate; acute ischemic stroke; autonomic dysfunction; deceleration capacity of heart rate; heart rate variability