title: Effect of left ventricular assist device on circulatory autonomic nervous activity.
abstract: OBJECTIVE
  For evaluation of the autonomic nervous system (ANS) activity of patients with mechanical circulatory support including LVAD, IABP and PCPS, arterial pressure variability (APV) was examined. APV is the power density values of pressure signals. High frequency (0.15 to 0.4 Hz) and low frequency (0.04 to 0.15 Hz) components of APV are regarded as a function of the autonomic nervous system.
  
  
  METHODS
  Arterial pressure signals were acquired every 2 hours at 100 Hz for 6 minutes. Power spectral analysis was carried out, and APV was observed in 18 patients with IABP and/or PCPS. APV was also observed in 3 patients with LVADs (Xemex, Zeon Medical, Japan) before their discharge from ICU for transfer to another hospital for cardiac transplantation.
  
  
  RESULTS
  Although the value gradually increased in 18 patients with IABP and/or PCPS, sustained low values of LFAnorm of APV in 6 patients were related to prolonged mechanical support, and 4 patients among them died consequently. The normalized power spectral component with low frequency (LFAnorm) was maintained at relatively high values in 3 patients with LVADs.
  
  
  CONCLUSIONS
  The study results suggest that power spectral analysis of systemic arterial pressure offers a reasonable means for the evaluation of the severity of patient cardiovascular condition and for the prediction of clinical outcome. It also suggested that LVAD support exerts a favorable effect on ANS in patients with severe heart failure before cardiac transplantation.
authors.affiliation: Department of Critical Care Medicine, Institute of Clinical Medicine, University of Tsukuba, Japan. ttsutsui@md.tsukuba.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Tsutsui
authors.forename: R
authors.initials: R
authors.lastname: Takiya
authors.forename: T
authors.initials: T
authors.lastname: Jikuya
authors.forename: O
authors.initials: O
authors.lastname: Shigeta
authors.forename: Y
authors.initials: Y
authors.lastname: Sakakibara
authors.forename: Y
authors.initials: Y
authors.lastname: Sankai
mesh_terms: D000328:Adult; D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001775:Blood Circulation / Q000502:physiology*; D001794:Blood Pressure; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy; D006353:Heart-Assist Devices; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome