title: Inspiratory muscle training in patients with heart failure: a systematic review.
abstract: OBJECTIVE
  The purpose of this review was to assess the quality of evidence on inspiratory muscle training (IMT) in patients with heart failure and to provide an overview on subject selection, training protocols, and outcome achieved with IMT.
  
  
  METHODS
  Literature search was first performed via the PubMed database, and additional references were identified from the Scopus citation index. Articles of the review type and of clinical trials published in English were included. Quality of the articles was assessed using Sackett's levels of evidence and rigor of methodology was assessed using PEDro (Physiotherapy Evidence Database) criteria for randomized controlled trials and the Downs & Black tool for cohort studies.
  
  
  RESULTS
  Twelve articles of clinical trials were included. Typical training protocols involved daily training with intensity greater than 30% of maximal inspiratory pressure (PImax), duration of 20 to 30 minutes (continuous or incremental) and using a pressure threshold muscle trainer. The effect sizes of PImax, walk test distance, and dyspnea were moderate to large across these studies. Effects on quality of life scores were inconsistent.
  
  
  CONCLUSIONS
  Inspiratory muscle training is beneficial for improving respiratory muscle strength, functional capacity, and dyspnea in patients with stable heart failure and respiratory muscle weakness.
authors.affiliation: Texas Woman's University, T. Boone Pickens Institute of Health Sciences - Dallas Center, School of Physical Therapy, Dallas, TX.
authors.forename: Suh-Jen
authors.initials: SJ
authors.lastname: Lin
authors.forename: Jessica
authors.initials: J
authors.lastname: McElfresh
authors.forename: Benjamin
authors.initials: B
authors.lastname: Hall
authors.forename: Rachel
authors.initials: R
authors.lastname: Bloom
authors.forename: Kellie
authors.initials: K
authors.lastname: Farrell