title: Using a blood pressure harmonic variability index to monitor the cerebral blood flow condition in stroke patients.
abstract: OBJECTIVE
  Beat-to-beat cardiovascular variability analysis provides important information on the autonomic control. Bilateral radial arterial blood pressure waveforms (BPW) in stroke patients were compared to explore the efficacy of frequency-domain variability index in evaluating bilateral differences in the cerebral blood-flow condition.
  
  
  METHODS
  Five-minute BPW signals were obtained in 22 stroke patients (Group S) and 21 healthy volunteers (control Group C). Amplitude proportions of the acquired pulses and their coefficient of variance (CVn) were calculated for 1st-10th harmonics to evaluate the blood pressure harmonic variability (BPHV).
  
  
  RESULTS
  In Group S, CV1-CV7 were significantly larger on the stroke side than on the contralateral side. CV1, CV3-CV5 and CV7 were significantly larger on the stroke side in Group S than on either side in Group C.
  
  
  CONCLUSIONS
  We first demonstrate the feasibility of using BPHV index to noninvasively detect the bilateral difference in cerebral vascular resistance in stroke patients. Two main indexes could be developed based on the present results: (1) bilateral differences in BPHV in stroke patients; (2) BPHV differences between normal and stroke subjects. It might have meaning in developing an easy-to-perform, noninvasive and continuous monitoring technique to improve the early detection and disease progress monitoring for stroke.
authors.affiliation: Department of Traditional Chinese Medicine, Taipei City Hospital RenAi Branch, Taipei, Taiwan, ROC.
authors.forename: Chao-Tsung
authors.initials: CT
authors.lastname: Chen
authors.forename: Shih-Min
authors.initials: SM
authors.lastname: Huang
authors.forename: Hsin
authors.initials: H
authors.lastname: Hsiu
authors.forename: Wei-Chen
authors.initials: WC
authors.lastname: Hsu
authors.forename: Feng-Cheng
authors.initials: FC
authors.lastname: Lin
authors.forename: Hung-Wen
authors.initials: HW
authors.lastname: Lin
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods*; D001921:Brain / Q000098:blood supply; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000503:physiopathology*