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ventilatory inefficiency

Sherin Hassan M Mehani, Heba Ahmed A Abdeen
[Purpose] Ventilatory limitation is a common problem in patients with chronic heart failure and pulmonary hypertension. Excess ventilation may arise from augmented ventilatory drive, over activity of chemoreceptors and muscle ergoreceptors, or premature onset of lactic acidosis. Exertional dyspnea can cause limitations in the activities of daily living and as a result, reduced quality of life for these patients. The aim of the present study was to evaluate the effect of cardiopulmonary rehabilitation program on ventilatory efficiency for these patients...
October 2017: Journal of Physical Therapy Science
Erik H Van Iterson, Bruce D Johnson, Barry A Borlaug, Thomas P Olson
AIMS: Patients with heart failure (HF) with reduced (HFrEF) or preserved (HFpEF) ejection fraction demonstrate an increased ventilatory equivalent for carbon dioxide (V̇E /V̇CO2 ) slope. The physiological correlates of the V̇E /V̇CO2 slope remain unclear in the two HF phenotypes. We hypothesized that changes in the physiological dead space to tidal volume ratio (VD /VT ) and arterial CO2 tension (PaCO2 ) differentially contribute to the V̇E /V̇CO2 slope in HFrEF vs. HFpEF. METHODS AND RESULTS: Adults with HFrEF (n = 32) and HFpEF (n = 27) [mean ± standard deviation (SD) left ventricular ejection fraction: 22 ± 7% and 61 ± 9%, respectively; mean ± SD body mass index: 28 ± 4 kg/m2 and 33 ± 6 kg/m2 , respectively; P < 0...
October 8, 2017: European Journal of Heart Failure
Piergiuseppe Agostoni, Marco Guazzi
No abstract text is available yet for this article.
October 9, 2017: European Journal of Heart Failure
Justin McNair Canada, Cory Ross Trankle, Leo Francis Buckley, Salvatore Carbone, Nayef Antar Abouzaki, Dinesh Kadariya, Keyur Shah, Richard Cooke, Michael Christopher Kontos, Jaideep Patel, Pranav Mankad, Aaron Schatz, Amit Bhatnagar, Ross Arena, Benjamin Wallace Van Tassell, Antonio Abbate
Hospital admission for decompensated heart failure marks a critical inflection point in a patient's health. Despite the improvement in signs or symptoms during hospitalization, patients have a high likelihood of readmission, reflecting a lack of resolution of the underlying condition. Surprisingly, no studies have characterized the cardiorespiratory fitness of such patients. Fifty-two patients (38 [73%] male, age 57 [52 to 65] years, left ventricular ejection fraction 31% [24 to 38]) underwent cardiopulmonary exercise testing 4 (1 to 10) days after hospital discharge, when stable and without overt signs of volume overload...
November 15, 2017: American Journal of Cardiology
Jesse M Charlton, Andrew H Ramsook, Reid A Mitchell, Michael A Hunt, Joseph H Puyat, Jordan A Guenette
PURPOSE: Aerobars place a cyclist in a position where the trunk is flexed forward and the elbows are close to the midline of the body. This position is known to improve cycling aerodynamics and time trial race performance compared with upright cycling positions. However, the aggressive nature of this position may have important cardiorespiratory and metabolic consequences. The purpose of this investigation was to examine the respiratory mechanical, ventilatory, metabolic, and sensory consequences of cycling while using aerobars during laboratory-based cycling...
December 2017: Medicine and Science in Sports and Exercise
Alcides Rocha, Flavio F Arbex, Priscilla A Sperandio, Aline Souza, Ligia Biazzim, Frederico Mancuso, Danilo C Berton, Bruno Hochhegger, Maria Clara N Alencar, Luiz E Nery, Denis E O'Donnell, J Alberto Neder
RATIONALE: An increased ventilatory response to exertional metabolic demand (high [Formula: see text]e/[Formula: see text]co2 relationship) is a common finding in patients with coexistent chronic obstructive pulmonary disease and heart failure. OBJECTIVES: We aimed to determine the mechanisms underlying high [Formula: see text]e/[Formula: see text]co2 and its impact on operating lung volumes, dyspnea, and exercise tolerance in these patients. METHODS: Twenty-two ex-smokers with combined chronic obstructive pulmonary disease and heart failure with reduced left ventricular ejection fraction undertook, after careful treatment optimization, a progressive cycle exercise test with capillary (c) blood gas collection...
November 15, 2017: American Journal of Respiratory and Critical Care Medicine
J M O'Connell, J M Weir, B R MacIntosh
Pulmonary oxygen uptake ([Formula: see text]) slowly increases during exercise above the anaerobic threshold, and this increase is called the slow component of [Formula: see text]. The mechanism of the increase in [Formula: see text] is assumed to be due to increasing energy cost associated with increasingly inefficient muscle contraction. We hypothesized that the increase in [Formula: see text] would be accompanied by a constant or increasing rate of accumulation of blood lactate, indicating sustained anaerobic metabolism while [Formula: see text] increased...
May 26, 2017: Pflügers Archiv: European Journal of Physiology
Alessandro Mezzani, Andrea Giordano, Klara Komici, Ugo Corrà
BACKGROUND: It is not known whether determinants of ventilation (VE)/volume of exhaled carbon dioxide (VCO2) slope during incremental exercise may differ at different stages of reduced ejection fraction chronic heart failure natural history. METHODS AND RESULTS: VE/VCO2 slope was fitted up to lowest VE/VCO2 ratio, that is, a proxy of the VE/perfusion ratio devoid of nonmetabolic stimuli to ventilatory drive. VE/VCO2 slope tertiles were generated from our database (<27...
May 9, 2017: Journal of the American Heart Association
Marco Guazzi, Debra Dixon, Valentina Labate, Lauren Beussink-Nelson, Francesco Bandera, Michael J Cuttica, Sanijv J Shah
OBJECTIVES: This study sought to investigate how right ventricular (RV) contractile function and its coupling with pulmonary circulation (PC) stratify clinical phenotypes and outcome in heart failure preserved ejection fraction (HFpEF) patients. BACKGROUND: Pulmonary hypertension and RV dysfunction are key hemodynamic abnormalities in HFpEF. METHODS: Three hundred eighty seven HFpEF patients (mean age 64 ± 12 years, 59% females, left ventricular ejection fraction 59 ± 7%) underwent RV and pulmonary hemodynamic evaluation by echocardiography (entire population) and right heart catheterization (219 patients)...
October 2017: JACC. Cardiovascular Imaging
Valentina Mantegazza, Anna Apostolo, Alfred Hager
Recently, the number of patients with congenital heart diseases reaching adulthood has been progressively increasing in developed countries, and new issues are emerging: the evaluation of their capacity to cope with physical activity and whether this knowledge can be used to optimize medical management. A symptom-limited cardiopulmonary exercise test has proven to be an essential tool, because it can objectively evaluate the functional cardiovascular capacity of these patients, identify the pathological mechanisms of the defect (circulatory failure, shunts, and/or pulmonary hypertension), and help prescribe an individualized rehabilitation program when needed...
July 2017: Annals of the American Thoracic Society
Jason Weatherald, Stefania Farina, Noemi Bruno, Pierantonio Laveneziana
Cardiopulmonary exercise testing allows the assessment of the integrative cardiopulmonary response to exercise and is a useful tool to assess the underlying pathophysiologic mechanisms leading to exercise intolerance. Patients with pulmonary hypertension often face a considerable delay in diagnosis due to the rarity of the disease and nonspecific symptoms of dyspnea, fatigue, and exercise limitation. Cardiopulmonary exercise testing may be suggestive of pulmonary hypertension in patients with evidence of both circulatory impairment and ventilatory inefficiency...
July 2017: Annals of the American Thoracic Society
J Alberto Neder, Danilo C Berton, Paulo de Tarso Müller, Amany F Elbehairy, Alcides Rocha, Paolo Palange, Denis E O'Donnell
Exertional dyspnea is present across the spectrum of chronic obstructive pulmonary disease (COPD) severity. However, without realizing it themselves, patients may decrease daily physical activity to avoid distressing respiratory sensations. Dyspnea also may be associated with deconditioning. Cardiopulmonary exercise testing can uncover exertional dyspnea and its physiological determinants in patients with preserved or only mildly reduced FEV1 . Dyspnea in mild COPD can largely be explained by increased "wasted" ventilation in the physiological dead space, which heightens the drive to breathe and worsens the inspiratory mechanical constraints...
July 2017: Annals of the American Thoracic Society
Antonella Lo Mauro, Andrea Aliverti
Muscular dystrophy is a group of inherited myopathies characterised by progressive skeletal muscle wasting, including of the respiratory muscles. Respiratory failure, i.e. when the respiratory system fails in its gas exchange functions, is a common feature in muscular dystrophy, being the main cause of death, and it is a consequence of lung failure, pump failure or a combination of the two. The former is due to recurrent aspiration, the latter to progressive weakness of respiratory muscles and an increase in the load against which they must contract...
December 2016: Breathe
Erik H Van Iterson, Courtney M Wheatley, Sarah E Baker, Thomas P Olson, Wayne J Morgan, Eric M Snyder
PURPOSE: Cystic fibrosis (CF) is commonly recognized as a pulmonary disease associated with reduced airway function. Another primary symptom of CF is low exercise capacity where ventilation and gas-exchange are exacerbated. However, an independent link between pathophysiology of the pulmonary system and abnormal ventilatory and gas-exchange responses during cardiopulmonary exercise testing (CPET) has not been established in CF. Complicating this understanding, accumulating evidence suggests CF demonstrate abnormal peripheral vascular function; although, the clinical implications are unclear...
2016: PloS One
Joshua H Jones, Joel T Zelt, Daniel M Hirai, Camilla V Diniz, Aida Zaza, Denis E O'Donnell, J Alberto Neder
There is growing evidence that emphysema on thoracic computed tomography (CT) is associated with poor exercise tolerance in COPD patients with only mild-to-moderate airflow obstruction. We hypothesized that an excessive ventilatory response to exercise (ventilatory inefficiency) would underlie these abnormalities. In a prospective study, 19 patients (FEV1 = 82 ± 13%, 12 Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 1) and 26 controls underwent an incremental exercise test. Ventilatory inefficiency was assessed by the ventilation ([Formula: see text]E)/CO2 output ([Formula: see text]CO2 ) nadir...
April 2017: COPD
Maria Clara Alencar, Flavio F Arbex, Aline Souza, Adriana Mazzuco, Priscila A Sperandio, Alcides Rocha, Daniel M Hirai, Frederico Mancuso, Danilo C Berton, Audrey Borghi-Silva, Dirceu Almeida, Denis E OʼDonnel, J Alberto Neder
PURPOSE: To investigate whether the opposite effects of heart failure (HF) and chronic obstructive pulmonary disease (COPD) on exercise ventilatory inefficiency (minute ventilation [(Equation is included in full-text article.)E]-carbon dioxide output [(Equation is included in full-text article.)CO2] relationship) would negatively impact its prognostic relevance. METHODS: After treatment optimization and an incremental cardiopulmonary exercise test, 30 male patients with HF-COPD (forced expiratory volume in 1 second [FEV1] = 57% ± 17% predicted, ejection fraction = 35% ± 6%) were prospectively followed up during 412 ± 261 days for major cardiac events...
November 2016: Journal of Cardiopulmonary Rehabilitation and Prevention
Hanneke Ac van Helvoort, Laura M Willems, Pn Richard Dekhuijzen, Hieronymus Wh van Hees, Yvonne F Heijdra
In patients with chronic obstructive pulmonary disease (COPD), exercise capacity is reduced, resulting over time in physical inactivity and worsened health status. It is unknown whether ventilatory constraints occur during activities of daily life (ADL) in early stages of COPD. The aim of this study was to assess respiratory mechanics during ADL and to study its consequences on dyspnoea, physical activity and health status in early-stage COPD compared with healthy controls. In this cross-sectional study, 39 early-stage COPD patients (mean FEV1 88±s...
October 13, 2016: NPJ Primary Care Respiratory Medicine
Alcides Rocha, Flavio F Arbex, Maria Clara N Alencar, Priscila A Sperandio, Daniel M Hirai, Danilo C Berton, Denis E O'Donnell, J Alberto Neder
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...
December 1, 2016: International Journal of Cardiology
B LoVerde, K S Firestone, H M Stein
OBJECTIVE: Neurally adjusted ventilatory assist (NAVA) is a mode of mechanical ventilation that delivers ventilatory support in synchrony to the patient's respiratory needs using NAVA level, a proportionality constant that converts the electrical activity of the diaphragm (Edi) into a peak pressure (PIP). Recent published studies suggest that neonates can control the delivered ventilatory support through neural feedback. Systematically increasing the NAVA level initially increases the PIP while maintaining a constant Edi until an inflection point or breakpoint (BrP) is reached, at which time the PIP plateaus and the Edi signal decreases...
December 2016: Journal of Perinatology: Official Journal of the California Perinatal Association
D M L Prado, E A Rocco, A G Silva, D F Rocco, M T Pacheco, V Furlan
The analysis of ventilatory efficiency in cardiopulmonary exercise testing has proven useful for assessing the presence and severity of cardiorespiratory diseases. During exercise, efficient pulmonary gas exchange is characterized by uniform matching of lung ventilation with perfusion. By contrast, mismatching is marked by inefficient pulmonary gas exchange, requiring increased ventilation for a given CO2 production. The etiology of increased and inefficient ventilatory response to exercise in heart disease is multifactorial, involving both peripheral and central mechanisms...
June 20, 2016: Brazilian Journal of Medical and Biological Research, Revista Brasileira de Pesquisas Médicas e Biológicas
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