title: Coronary artery bypass surgery and longitudinal evaluation of the autonomic cardiovascular function.
abstract: BACKGROUND
  Imbalance in autonomic cardiovascular function increases the risk for sudden death in patients with coronary artery disease (CAD), but the time course of the impact of coronary artery bypass grafting (CABG) on autonomic function has been little studied. Thus, the purpose of the present study was to determine the effects of the CABG on the cardiovascular autonomic function.
  
  
  METHODS
  Patients undergoing CABG (n = 13) and two matched control groups (patients with CAD who refused surgical treatment [n = 9], and healthy volunteers [n = 9]) underwent a prospective longitudinal study consisting of autonomic evaluation before and after (3, 6, 15, 30, 60, and 90 days) surgery, including measurement of heart rate variability (HRV), respiratory sinus arrhythmia (RSA), and Valsalva maneuver.
  
  
  RESULTS
  After CABG there was a decrease in, and a later recovery of, (1) the HRV in the time domain and in the frequency domain, (2) RSA, and (3) Valsalva maneuver.
  
  
  CONCLUSIONS
  CABG caused an impairment, reversible after 60 days, of cardiovascular autonomic function, with a maximal decrease on about the sixth day after surgery.
authors.affiliation: Department of Physiology and Pharmacology, Universidade Federal Fluminense, Niterói, RJ, Brazil. pedro.soares@incor.usp.br
authors.forename: Pedro Paulo S
authors.initials: PP
authors.lastname: Soares
authors.forename: Adalgiza M
authors.initials: AM
authors.lastname: Moreno
authors.forename: Sérgio L D
authors.initials: SL
authors.lastname: Cravo
authors.forename: Antonio Claudio L
authors.initials: AC
authors.lastname: Nóbrega
mesh_terms: D001146:Arrhythmia, Sinus / Q000175:diagnosis; D001341:Autonomic Nervous System / Q000502:physiology*; D002320:Cardiovascular Physiological Phenomena; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000534:rehabilitation; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011184:Postoperative Period; D011446:Prospective Studies; D020127:Recovery of Function; D012143:Respiratory Physiological Phenomena; D013997:Time Factors; D014636:Valsalva Maneuver