title: Heart rate variability analysed by Poincaré plot in patients with metabolic syndrome.
abstract: BACKGROUND
  The SD1 and SD2 indexes (standard deviations in two orthogonal directions of the Poincaré plot) carry similar information to the spectral density power of the high and low frequency bands but have the advantage of easier calculation and lesser stationarity dependence.
  
  
  METHODS
  ECG signals from metabolic syndrome (MetS) and control group patients during tilt table test under controlled breathing (20 breaths/minute) were obtained. SD1, SD2, SDRR (standard deviation of RR intervals) and RMSSD (root mean square of successive differences of RR intervals) were evaluated for 31 control group and 33 MetS subjects.
  
  
  RESULTS
  Statistically significant lower values were observed in MetS patients in supine position (SD1: p=0.03, SD2: p=0.002, SDRR: p=0.006, RMSSD: p=0.01) and during tilt (SD2: p=0.004, SDRR: p=0.007).
  
  
  CONCLUSIONS
  SD1 and SD2 combining the advantages of time and frequency domain methods, distinguish successfully between MetS and control subjects.
authors.affiliation: Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Technická 3082/12, Královo Pole, Brno, Czech Republic. Electronic address: drkosova@phd.feec.vutbr.cz.
authors.forename: Alena
authors.initials: A
authors.lastname: Kubičková
authors.affiliation: Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Technická 3082/12, Královo Pole, Brno, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Kozumplík
authors.affiliation: Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, Bohunice, Brno, Czech Republic.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Nováková
authors.affiliation: Second Department of Internal Medicine, St. Anne's University Hospital Brno and Faculty of Medicine, Masaryk University, Pekařská 53, Brno, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Plachý
authors.affiliation: Institute of Scientific Instruments, Academy of Sciences of the Czech Republic, Královopolská 147, Brno, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Jurák
authors.affiliation: First Internal Cardioangiology Clinic, St. Anne's University Hospital Brno and Faculty of Medicine, Masaryk University, Pekařská 53, Brno, Czech Republic.
authors.forename: Jolana
authors.initials: J
authors.lastname: Lipoldová
mesh_terms: D000328:Adult; D000465:Algorithms; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000503:physiopathology*; D003936:Diagnosis, Computer-Assisted; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000175:diagnosis* / Q000503:physiopathology*; D009991:Oscillometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Poincaré plot; controlled breathing; heart rate variability; metabolic syndrome; tilt table test