title: Poincaré plot indexes of heart rate variability detect dynamic autonomic modulation during general anesthesia induction.
abstract: OBJECTIVE
  Beat-to-beat heart rate variability (HRV) is caused by the fluctuating balance of sympathetic and parasympathetic tone. The Poincaré plot has been used to evaluate HRV. In this study, we validate that this new method may qualitatively and quantitatively assess the sympathovagal fluctuation in patients during induction of anesthesia with sevoflurane.
  
  
  METHODS
  Twenty-eight young patients were allocated for the study. The patients received a tilt test and on the next day they sustained anesthesia induced with inhaled anesthetics. Electrocardiography signals from the patients were relayed to an analogue-digital converter. The Poincaré plot is quantified by measuring SD1, SD2, and SD1/SD2. Power spectral analyses were performed and LF, HF and HF/LF were calculated.
  
  
  RESULTS
  The LF power and the SD2 of the Poincaré plot increased while subjects were tilt-up from the supine position. Additionally, a significant correlation were found between LF and SD2, HF and SD1 (p < 0.05), and LF/HF and SD2/SD1 (p < 0.01). Sevoflurane inhalation for 10 minutes had no effect on heart rate, but diminished LF, total power and SD1, SD2 of the Poincaré plot respectively. However, the LF, SD2 and LF/HF increased; the HF, SD1 and SD1/SD2 ratio decreased after intubation stimulation.
  
  
  CONCLUSIONS
  Poincaré plot and power spectral analysis of HRV during tilt test and sevoflurane induction significantly correlate. Poincaré plot analysis is easier and more sensitive at evaluating the sympathovagal balance and observing the beat-to-beat HRV.
authors.affiliation: Department of Anesthesiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Che-Hao
authors.initials: CH
authors.lastname: Hsu
authors.forename: Ming-Ya
authors.initials: MY
authors.lastname: Tsai
authors.forename: Go-Shine
authors.initials: GS
authors.lastname: Huang
authors.forename: Tso-Chou
authors.initials: TC
authors.lastname: Lin
authors.forename: Kuen-Pao
authors.initials: KP
authors.lastname: Chen
authors.forename: Shung-Tai
authors.initials: ST
authors.lastname: Ho
authors.forename: Liang-Yu
authors.initials: LY
authors.lastname: Shyu
authors.forename: Chi-Yuan
authors.initials: CY
authors.lastname: Li
mesh_terms: D000768:Anesthesia, General; D001341:Autonomic Nervous System / Q000503:physiopathology*; D004562:Electrocardiography; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology; D011187:Posture; D000077149:Sevoflurane; D018667:Tilt-Table Test; D055815:Young Adult
chemical_list: D008738:Methyl Ethers; D000077149:Sevoflurane