title: Physiological and sensory consequences of exercise oscillatory ventilation in heart failure-COPD.
abstract: BACKGROUND
  Exercise oscillatory ventilation (EOV) is associated with poor ventilatory efficiency and higher operating lung volumes in heart failure. These abnormalities may be particularly deleterious to dyspnea and exercise tolerance in mechanically-limited patients, e.g. those with coexistent COPD.
  
  
  METHODS
  Ventilatory, gas exchange and sensory responses to incremental exercise were contrasted in 68 heart failure-COPD patients (12 EOV+). EOV was established by standard criteria.
  
  
  RESULTS
  Compared to EOV-, EOV+ had lower exercise capacity, worse ventilatory inefficiency and higher peak dyspnea scores (p<0.05). Peak capillary PCO2(PcCO2) was higher and end-tidal CO2(PETCO2) was lower in EOV+. Thus, greater (i.e., more positive) P(c-ET)CO2and dead space/tidal volume values were found in these patients compared to EOV- (p<0.05). Ventilatory inefficiency was related to increased dead space/tidal volume in EOV+ (r=0.74; p<0.01). Owing to higher operating lung volumes, inspiratory reserve volume (IRV) decreased to a greater extent in EOV+. Tidal volume oscillations consistently ceased when a "critical" IRV was reached (~0.3-0.5L); thereafter, PcCO2stabilized or increased and dyspnea scores rose sharply. Exercise capacity was closely related to IRV decrements and peak dyspnea in EOV+ (r=-0.78 and 0.84, respectively; p<0.01).
  
  
  CONCLUSIONS
  Dyspnea and exercise tolerance are negatively influenced by EOV in heart failure patients presenting with COPD as co-morbidity. Pharmacological and non-pharmacological interventions known to decrease EOV might prove particularly valuable to mitigate symptom burden and exercise intolerance in this specific heart failure group.
authors.affiliation: Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Alcides
authors.initials: A
authors.lastname: Rocha
authors.affiliation: Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Flavio F
authors.initials: FF
authors.lastname: Arbex
authors.affiliation: Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Maria Clara N
authors.initials: MC
authors.lastname: Alencar
authors.affiliation: Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Priscila A
authors.initials: PA
authors.lastname: Sperandio
authors.affiliation: Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil; Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Queen's University, Kingston General Hospital, Kingston, ON, Canada.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Hirai
authors.affiliation: Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Queen's University, Kingston General Hospital, Kingston, ON, Canada; Division of Respirology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Danilo C
authors.initials: DC
authors.lastname: Berton
authors.affiliation: Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Queen's University, Kingston General Hospital, Kingston, ON, Canada.
authors.forename: Denis E
authors.initials: DE
authors.lastname: O'Donnell
authors.affiliation: Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil; Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Queen's University, Kingston General Hospital, Kingston, ON, Canada. Electronic address: alberto.neder@queensu.ca.
authors.forename: J Alberto
authors.initials: JA
authors.lastname: Neder
mesh_terms: D000368:Aged; D004417:Dyspnea / Q000209:etiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology; D012123:Pulmonary Ventilation / Q000502:physiology; D012129:Respiratory Function Tests / Q000379:methods; D013223:Statistics as Topic
keywords: COPD; Dyspnea; Exertion; Heart failure; Lung mechanics; Ventilation