title: [The exercise training restores the heart rate variability in heart failure patients. A systematic review].
abstract: Cardiovascular diseases are a significant cause of morbidity and mortality in the general population. In this sense, the autonomic imbalance is the cornerstone of the pathophysiology underlying the development of these diseases. The aim of this study was to determine the efficacy of exercise training on heart rate variability (HRV) in adult patients with chronic heart failure.
  
  
  METHODS
  A systematic literature review was conducted in electronic databases. The considered studies were randomised clinical trials, quasi-experimental studies with non-randomised control group, quasi-experimental studies with analysis of pre- and post- intervention, and crossover studies with randomly assigned training and non-training periods. The standardised mean differences were calculated between pre- and post-intervention in both the control and experimental group.
  
  
  RESULTS
  Within-subject analysis of the control group showed no statistical significance in the standardised mean differences of HRV. In the experimental group, the standardised mean differences were positive for the root mean square of successive difference (+0.468±0.215; P=.032), high frequency band (HF) (0.934±0.256; P < .001) and low frequency band (LF) (< 0.415±0.096; P=.001). Moreover, the standardised mean difference was negative for LF/HF (-0.747±0.369, P=<.044). On the other hand, only 3 studies entered the comparative meta-analysis. The effect of exercise training was favourable for the experimental group in LF/HF (-2.21±95% CI: -3.83 to -0.60), HF, and LF.
  
  
  CONCLUSIONS
  The exercise training was effective in increasing HRV and restoring the autonomic balance in patients with heart failure.
authors.affiliation: Programa de Magíster en Kinesiología Cardiorrespiratoria, Escuela de Kinesiología, Facultad de Ciencias de la Salud, Universidad San Sebastián, Concepción, Chile; Facultad de Medicina, Universidad Católica del Norte, Coquimbo, Chile.
authors.forename: Victoria
authors.initials: V
authors.lastname: Segovia
authors.affiliation: Departamento de Cirugía y CEMyQ, Universidad de La Frontera, Temuco, Chile; Centro de investigaciones biomédicas, Universidad Autónoma de Chile, Temuco, Chile.
authors.forename: Carlos
authors.initials: C
authors.lastname: Manterola
authors.affiliation: Laboratorio de Fisiología Vascular, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción Chile.
authors.forename: Marcelo
authors.initials: M
authors.lastname: González
authors.affiliation: Programa de Magíster en Kinesiología Cardiorrespiratoria, Escuela de Kinesiología, Facultad de Ciencias de la Salud, Universidad San Sebastián, Concepción, Chile; Laboratorio de Biología del Ejercicio, Escuela de Kinesiología, Facultad de Ciencias de la Salud, Universidad San Sebastián, Concepción, Chile. Electronic address: ivan.rodriguez@uss.cl.
authors.forename: Iván
authors.initials: I
authors.lastname: Rodríguez-Núñez
mesh_terms: D005081:Exercise Therapy; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006339:Heart Rate; D006801:Humans; D020127:Recovery of Function
keywords: Autonomic nervous system; Chile; Ejercicio; Entrenamiento; Exercise; Heart failure; Insuficiencia cardiaca; Sistema nervioso autónomo; Training