title: Exercise Ventilation in COPD: Influence of Systolic Heart Failure.
abstract: Systolic heart failure is a common and disabling co-morbidity of chronic obstructive pulmonary disease (COPD) which may increase exercise ventilation due to heightened neural drive and/or impaired pulmonary gas exchange efficiency. The influence of heart failure on exercise ventilation, however, remains poorly characterized in COPD. In a prospective study, 98 patients with moderate to very severe COPD [41 with coexisting heart failure; 'overlap' (left ventricular ejection fraction < 50%)] underwent an incremental cardiopulmonary exercise test (CPET). Compared to COPD, overlap had lower peak exercise capacity despite higher FEV1. Overlap showed lower operating lung volumes, greater ventilatory inefficiency and larger decrements in end-tidal CO2(PETCO2) (P < 0.05). These results were consistent with those found in FEV1-matched patients. Larger areas under receiver operating characteristic curves to discriminate overlap from COPD were found for ventilation ([Formula: see text]E)-CO2output [Formula: see text]CO2) intercept, [Formula: see text]E-[Formula: see text]CO2slope, peak [Formula: see text]E/[Formula: see text]CO2ratio and peak PETCO2. Multiple logistic regression analysis revealed that [Formula: see text]CO2intercept ≤ 3.5 L/minute [odds ratios (95% CI) = 7.69 (2.61-22.65), P < 0.001] plus [Formula: see text]E-[Formula: see text]CO2slope ≥ 34 [2.18 (0.73-6.50), P = 0.14] or peak [Formula: see text]E/[Formula: see text]CO2ratio ≥ 37 [5.35 (1.96-14.59), P = 0.001] plus peak PETCO2≤ 31 mmHg [5.73 (1.42-23.15), P = 0.01] were indicative of overlapping. Heart failure increases the ventilatory response to metabolic demand in COPD. Variables reflecting excessive ventilation might prove useful to assist clinical interpretation of CPET responses in COPD patients presenting heart failure as co-morbidity.
authors.affiliation: a 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: a Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo , Sao Paulo , Brazil.
authors.forename: Maria Clara
authors.initials: MC
authors.lastname: Alencar
authors.affiliation: a Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo , Sao Paulo , Brazil.
authors.forename: Aline
authors.initials: A
authors.lastname: Souza
authors.affiliation: d Department of Physiotherapy , Federal University of Sao Carlos , Sao Carlos , Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Mazzuco
authors.affiliation: a 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: a 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: a Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo , Sao Paulo , Brazil.|b Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Queen's University and Kingston General Hospital , Kingston , Canada.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Hirai
authors.affiliation: c Division of Cardiology, Federal University of Sao Paulo , Sao Paulo , Brazil.
authors.forename: Frederico
authors.initials: F
authors.lastname: Mancuso
authors.affiliation: e 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: d Department of Physiotherapy , Federal University of Sao Carlos , Sao Carlos , Brazil.
authors.forename: Audrey
authors.initials: A
authors.lastname: Borghi-Silva
authors.affiliation: c Division of Cardiology, Federal University of Sao Paulo , Sao Paulo , Brazil.
authors.forename: Dirceu R
authors.initials: DR
authors.lastname: Almeida
authors.affiliation: b Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Queen's University and Kingston General Hospital , Kingston , Canada.
authors.forename: Denis E
authors.initials: DE
authors.lastname: O'Donnell
authors.affiliation: a Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo , Sao Paulo , Brazil.|b Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Queen's University and Kingston General Hospital , Kingston , Canada.
authors.forename: J Alberto
authors.initials: JA
authors.lastname: Neder
mesh_terms: D000368:Aged; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D017079:Exercise Tolerance; D005541:Forced Expiratory Volume; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000503:physiopathology*; D011659:Pulmonary Gas Exchange; D012123:Pulmonary Ventilation; D013318:Stroke Volume; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000503:physiopathology
keywords: Carbon dioxide; cardiopulmonary exercise testing; dyspnoea; exertion; gas exchange