title: [Effect of age on electrocardiogram entropy value of parameters by sleep respiratory disturbance].
abstract: BACKGROUND
  Spectral entropy of electrocardiogram (ECG), which was calculated using the MemCalc method with a portable bio-signal measurement instrument (PBSM), might be a possible parameter for evaluating the quality of sleep.
  
  
  OBJECTIVE
  This study assessed the effects of ECG spectral entropy on obstructive sleep apnea/hypopnea syndrome (OSAHS) depending on age.
  
  
  METHODS
  ECG was recorded using a PBSM, and the maximum entropy of ECG every 9 RR intervals was calculated. These entropies were compared with the age and sleeping indices obtained with a conventional polysomnography (PSG) system.
  
  
  METHODS
  Seventy-six patients suspected of OSAHS were recorded from 20:00 to 06:00 using a conventional PSG system (Alice III) and a PBSM (MemCalc-Makin2) simultaneously.
  
  
  RESULTS
  ECG entropy showed correlations to high frequency (HF, 0.15-0.40 Hz) heart rate variability in the cardiac parasympathetic activity index, as did the ECG entropy value, and a negative correlation was found with the age (r = 0.538, p < 0.0001), and positive correlation with the HF value (r = 0.810, p < 0.0001). The ECG entropy value in subjects aged > or = 40 with no different sleep respiratory disturbance index by PSG data (AHI, Arousal Index, DSI, and sleep efficiency, etc.) to 60 years old was compared with those aged > or = 60. The ECG entropy value and HF value decreased at > or = 60 years old with statistically significant.
  
  
  CONCLUSIONS
  The value of ECG entropy corresponds to cardiac parasympathetic function, and it decreases according to age (increase by the absolute value).
authors.affiliation: Department of Clinical Laboratory, Tohoku University Hospital, Sendai 980-8574, Japan. bigkyu-thk@umin.ac.jp
authors.forename: Noriko
authors.initials: N
authors.lastname: Ohisa
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Ogawa
authors.forename: Toshiya
authors.initials: T
authors.lastname: Irokawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Kurosawa
authors.forename: Katsumi
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D004562:Electrocardiography; D019277:Entropy; D005260:Female; D006321:Heart / Q000294:innervation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*