title: Alterations of autonomic nervous activity in recurrence of variant angina.
abstract: OBJECTIVE
  To investigate whether autonomic nervous activity is involved in the recurrence of spontaneous coronary spasm in variant angina.
  
  
  METHODS
  Retrospective analysis.
  
  
  METHODS
  Cardiology department of a university hospital.
  
  
  METHODS
  18 patients with variant angina were divided into single attack group (SA; nine patients) and multiple attack group (MA; nine patients) according to the frequency of ischaemic episodes with ST segment elevation during 24 hour Holter monitoring.
  
  
  METHODS
  Heart rate variability indices were calculated using MemCalc method, which is a combination of the maximum entropy method for spectral analysis and the non-linear least squares method for fitting analysis, at 30 second intervals for 30 second periods, from 40 minutes before the attack to 30 minutes after the attack. High frequency (HF; 0.04-0.15 Hz) was defined as a marker of parasympathetic activity, and the ratio of low frequency (LF; 0.15-0.40 Hz) to high frequency (LF/HF) as an indicator of sympathetic activity. The averaged value during the 40 to 30 minute period before an attack was defined as the baseline.
  
  
  RESULTS
  Compared with baseline, the HF component decreased in both groups at two minutes before the attack (p < 0.01), and the LF/HF ratio decreased at three minutes before the attack (p < 0.01). The baseline LF/HF was lower in the MA group than in the SA group (p < 0. 01).
  
  
  CONCLUSIONS
  A reduction of sympathetic activity may play a key role in determining the recurrence of transient ischaemic events caused by spontaneous coronary spasm in patients with variant angina.
authors.affiliation: The Second Department of Internal Medicine, Yamanashi Medical University, 1110 Shimokato, Tamaho, Yamanashi 409-3898, Japan. mtaku@res.yamanashi-med.sc.jp
authors.forename: M
authors.initials: M
authors.lastname: Takusagawa
authors.forename: S
authors.initials: S
authors.lastname: Komori
authors.forename: K
authors.initials: K
authors.lastname: Umetani
authors.forename: T
authors.initials: T
authors.lastname: Ishihara
authors.forename: T
authors.initials: T
authors.lastname: Sawanobori
authors.forename: I
authors.initials: I
authors.lastname: Kohno
authors.forename: S
authors.initials: S
authors.lastname: Sano
authors.forename: D
authors.initials: D
authors.lastname: Yin
authors.forename: H
authors.initials: H
authors.lastname: Ijiri
authors.forename: K
authors.initials: K
authors.lastname: Tamura
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D000788:Angina Pectoris, Variant / Q000503:physiopathology*; D001341:Autonomic Nervous System / Q000503:physiopathology*; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted