title: Impact of device-guided slow breathing on symptoms of chronic heart failure: a randomized, controlled feasibility study.
abstract: OBJECTIVE
  In many patients with chronic heart failure (CHF) even normal daily life activities cause dyspnoea and fatigue, well-being might be considerably improved by even a modest decrease in such symptoms. The aim of this study was to investigate if lowering breathing rate with the help of a respiratory modulation (RM) device could improve symptoms in patients with CHF.
  
  
  RESULTS
  Stable CHF patients with symptoms of dyspnoea were randomized to twice-daily 20 min sessions using an RM device or to music listening (ML) using a CD player, for a 4-week study period. Respiratory modulation guides the user to achieve a slow breathing rate (<10 breaths/min) while increasing exhalation time (Tex) relative to inhalation time (Tin). Lower breathing rate was accomplished by synchronizing respiratory movements with musical tones generated in response to breathing movements monitored with a belt-type sensor. Endpoints were reduced breathlessness and New York Heart Association (NYHA) class. Seventy-two patients (52 male, age 73 ± 11 years, NYHA 3.1 ± 0.9) were randomized and 65 completed the study (30 RM and 35 ML, respectively). There was no in-between group improvement in breathlessness and NYHA class. Patients in the RM group who displayed an average increase in Tex/Tin of >0.2 and a reduction in the average respiration rate during 30 sessions were considered responders. Responders reported reduced breathlessness (-0.86 ± 0.23 units, P < 0.005) and improved NYHA class (-0.64 ± 0.20, P < 0.01) compared with non-responders.
  
  
  CONCLUSIONS
  Device-guided RM might have the potential to relieve symptoms of heart failure in outpatients by changing their breathing pattern.
authors.affiliation: Institute of Health and Care Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden.
authors.forename: Inger
authors.initials: I
authors.lastname: Ekman
authors.forename: Barbro
authors.initials: B
authors.lastname: Kjellström
authors.forename: Kristin
authors.initials: K
authors.lastname: Falk
authors.forename: Jonna
authors.initials: J
authors.lastname: Norman
authors.forename: Karl
authors.initials: K
authors.lastname: Swedberg
mesh_terms: D000368:Aged; D004417:Dyspnea / Q000503:physiopathology / Q000628:therapy; D005240:Feasibility Studies; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D012138:Respiratory Therapy / Q000295:instrumentation*; D012720:Severity of Illness Index; D016896:Treatment Outcome