title: Blood pressure changes in patients with chronic heart failure undergoing slow breathing training.
abstract: BACKGROUND
  Slow breathing training (SBT) has been proposed as a new non-pharmacological treatment able to induce favorable effects in patients with chronic heart failure (CHF). However, no information is available regarding its effects on orthostatic blood pressure (BP) changes in these patients, an issue of practical relevance given the reported BP-lowering effect of SBT. The aim of this study is to evaluate the influence of SBT on BP and whether SBT induces orthostatic hypotension (OH) or changes in quality of life (QoL) in CHF patients.
  
  
  METHODS
  The analysis was performed as part of an ongoing crossover open trial aimed at assessing the clinical effectiveness of SBT in treated patients with CHF. The patients underwent 10-12 weeks of SBT with the RESPeRATE device and 10-12 week follow-up under usual care. Patients were randomly divided into two groups: group I began with SBT, followed by usual care; group II began with usual care, followed by SBT. Patients undergoing SBT were asked to perform each day two separate 15 min sessions of device-guided SBT at a breathing frequency of 6 breaths/min. In all patients, before the enrollment and after each study phase, clinical data collection and BP measurements in sitting, supine and standing position were performed. OH was defined as a decrease of ≥ 20 mmHg in systolic blood pressure (SBP) or ≥ 10 mmHg in diastolic blood pressure (DBP) within 3 min of standing. QoL was assessed three times at the beginning, and after each phase of the study by the Minnesota Living with Heart Failure (MLHF) questionnaire.
  
  
  RESULTS
  Forty patients (two equal groups) completed the study, with the following baseline characteristics: 32 males/eight females, age 63.3 ± 13.4 years, 25 with ischemic CHF, 37 in New York Heart Association class II and three in class III, left ventricular ejection fraction 30.8 ± 6.7%, mean BP 138.7 ± 16.5/83.1 ± 11.5 mmHg, 23 with arterial hypertension and four with a history of stroke. There were no significant differences between the groups in clinical characteristics, SBP and DBP at rest, while seated and before and after standing up. OH prevalence was low and did not change during the study (10% vs 10%). No significant difference in average SBP and DBP changes secondary to body position were found when comparing the two study phases. Decrease in MLHF score was observed in group I during SBT (p = 0.002), but not in group II.
  
  
  CONCLUSIONS
  Our data indicate that SBT is safe, does not affect the prevalence of OH in CHF patients and shows a non-significant tendency to improve QoL. These results should be confirmed in a larger sample of patients to support the safety of SBT and its possible benefits as a novel component of cardiorespiratory rehabilitation programs in CHF.
authors.affiliation: a Department of Cardiology, Interventional Cardiology and Hypertension , Jagiellonian University Medical College , Krakow , Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Drozdz
authors.affiliation: b Department of Cardiovascular, Neural and Metabolic Sciences , San Luca Hospital, IRCCS Istituto Auxologico Italiano , Milan , Italy.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Bilo
authors.affiliation: a Department of Cardiology, Interventional Cardiology and Hypertension , Jagiellonian University Medical College , Krakow , Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Debicka-Dabrowska
authors.affiliation: a Department of Cardiology, Interventional Cardiology and Hypertension , Jagiellonian University Medical College , Krakow , Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Klocek
authors.affiliation: b Department of Cardiovascular, Neural and Metabolic Sciences , San Luca Hospital, IRCCS Istituto Auxologico Italiano , Milan , Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Malfatto
authors.affiliation: a Department of Cardiology, Interventional Cardiology and Hypertension , Jagiellonian University Medical College , Krakow , Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Kielbasa
authors.affiliation: a Department of Cardiology, Interventional Cardiology and Hypertension , Jagiellonian University Medical College , Krakow , Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Styczkiewicz
authors.affiliation: a Department of Cardiology, Interventional Cardiology and Hypertension , Jagiellonian University Medical College , Krakow , Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Bednarek
authors.affiliation: a Department of Cardiology, Interventional Cardiology and Hypertension , Jagiellonian University Medical College , Krakow , Poland.
authors.forename: Danuta
authors.initials: D
authors.lastname: Czarnecka
authors.affiliation: b Department of Cardiovascular, Neural and Metabolic Sciences , San Luca Hospital, IRCCS Istituto Auxologico Italiano , Milan , Italy.|c Department of Health Sciences , University of Milano-Bicocca , Milan , Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Parati
authors.affiliation: a Department of Cardiology, Interventional Cardiology and Hypertension , Jagiellonian University Medical College , Krakow , Poland.
authors.forename: Kalina
authors.initials: K
authors.lastname: Kawecka-Jaszcz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D001945:Breathing Exercises / Q000379:methods* / Q000523:psychology; D002908:Chronic Disease; D018592:Cross-Over Studies; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D007024:Hypotension, Orthostatic / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011187:Posture; D011788:Quality of Life / Q000523:psychology*; D013318:Stroke Volume; D011795:Surveys and Questionnaires
keywords: Blood pressure; chronic heart failure; orthostatic hypotension; slow breathing training