title: Analysis of heart rate variability at rest and during aerobic exercise: a study in healthy people and cardiac patients.
abstract: OBJECTIVE
  To analyse HRV at rest in healthy people and in patients with acute myocardial infarction (AMI) and how it changes during aerobic exercise.
  
  
  METHODS
  The heartbeat signal was recorded beat to beat for 15 minutes at rest and 15 minutes while pedalling in 10 healthy and active men (H group) and 10 cardiac patients (C group). The statistical parameters in the time domain were calculated as well as the spectral analysis applying the Fast Fourier Transform (FFT) and Poincare's graphic analysis (PGA).
  
  
  RESULTS
  At rest, H group have an average SDRR (standard deviation of RR intervals) of 71.24 msec, a pRR50 (percentage of differences higher than 50 msec in RR intervals) of 9.97% and a PGA called "comet-type". The C group have a SDRR of 36.69 msec, a pRR50 of 1.69%, and a PGA "torpedo-type". These data show a low or moderate risk for healthy people and a high risk for patients. The FFT analysis lies in the very-low-frequency (VLF) zone in both groups. During exercise, H group shows a significant decrease in all parameters; the PGA turns to "torpedo-type" and the FFT remains in the VLF zone. However, C group is characterised by the maintenance of pRR50, no change in PGA and a second peak in FFT in the high-frequency zone.
  
  
  CONCLUSIONS
  The HRV at rest and during aerobic exercise follows a different pattern in healthy people and in patients and it provides further information about performance during exercise.
authors.affiliation: Centro Andaluz de Medicina del Deporte, CAR La Cartuja, Isla de la Cartuja s/n Sevilla, 41092, Spain.
authors.forename: B
authors.initials: B
authors.lastname: de la Cruz Torres
authors.forename: C
authors.initials: C
authors.lastname: López López
authors.forename: J
authors.initials: J
authors.lastname: Naranjo Orellana
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D005583:Fourier Analysis; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*; D012146:Rest / Q000502:physiology*; D012307:Risk Factors