BACKGROUND: Pulmonary diffusing capacity for carbon monoxide (D1co), alveolar capillary membrane diffusing capacity (Dm), and pulmonary capillary blood volume (Vc) are all significantly reduced after exercise. OBJECTIVE: To investigate whether measurement position affects this impaired gas transfer. METHODS: Before and one, two, and four hours after incremental cycle ergometer exercise ...

The mechanisms for exercise intolerance in chronic obstructive pulmonary disease are complex and multifaceted. Although ventilatory limitation caused by abnormal pulmonary function is a major contributor to this phenomenon, other factors may play an important role in limiting exercise. These other factors include depressed cardiac function, respiratory and peripheral muscle ...

BACKGROUND: Although some patients report favorable activity levels late after partial left ventriculectomy (PLV), their exercise physiology has not been well described. METHODS AND RESULTS: We performed upright bicycle hemodynamics in 10 patients (9 men) aged 56+/-12 years at 1.7 years after PLV. Ejection fraction was 25+/-4%. Patients biked 10+/-7 ...

Angiotensin converting enzyme (ACE) plays an important role in the pathogenesis of pulmonary hypertension. In this study we determined whether the deletion (D)/insertion (I) polymorphism in the ACE gene may be associated with pulmonary hypertension evoked by exercise challenge in patients with chronic obstructive pulmonary disease (COPD). ACE genotypes were ...

In animals, the J reflex evoked by pulmonary C fibers provides potent inhibition of limb muscles and would act to limit exercise. However, recent work shows that although activation of these fibers causes severe respiratory discomfort, it does not impair the output of limb motoneurons to voluntary, reflex, or locomotor ...

The effect of incremental exercise to exhaustion on the change in pulmonary clearance rate (k) of aerosolized (99m)Tc-labeled diethylenetriaminepentaacetic acid ((99m)Tc-DTPA) and the relationship between k and arterial PO(2) (Pa(O(2))) during heavy work were investigated. Ten male cyclists (age = 25 +/- 2 yr, height = 180.9 +/- 4.0 cm, ...

OBJECTIVES: The purpose of this study was to investigate the responses of patients with primary pulmonary hypertension (PPH) to constant work rate exercise and to examine the effect of nitric oxide (NO) inhalation. BACKGROUND: Maximal exercise tolerance is reduced in PPH, but gas exchange responses to constant work rate exercise ...

It is recognized that exercise produces abnormally large increases in pulmonary artery pressure in patients with pulmonary vascular disease as a consequence of a variety of disorders, but the relationship between pressure and cardiopulmonary exercise performance is poorly understood. This lack of understanding is due (in part) to difficulty making ...

Two almost identical elderly women are described who presented with gradually progressive painless involuntary flexion of the ring and middle fingers over 12 months, leading eventually to contractures. The flexion deformity persisted during sleep and was the sole neurological abnormality. Both patients had advanced chronic obstructive pulmonary disease and were ...

The carotenoid compound crocetin has been hypothesized to enhance the diffusion of O(2) through plasma, and observations in the rat and rabbit have revealed improvement in arterial PO(2) when crocetin is given. To determine whether crocetin enhances diffusion of O(2) between alveolar gas and the red blood cell in the ...

OBJECTIVE: It is a well-known fact that pulmonary function is altered in ankylosing spondylitis (AS) mainly due to the restriction of chest wall movements. The objective of this study was to investigate whether alterations in pulmonary function affected exercise capacity. METHODS: Twenty male patients with definite AS and 20 age-matched ...

The present work focuses on pulmonary gas exchange during repeated rowing to exhaustion and the recovery of pulmonary diffusion capacity for carbon monoxide (DL) after exercise in healthy young subjects. The components of DL are examined at rest using the single breath method at two different alveolar O2 tensions. Electrical ...

BACKGROUND: The continuous infusion of prostacyclin has been shown to improve exercise capacity and survival in patients with primary pulmonary hypertension (PPH). Inhalation of iloprost, a stable analog of prostacyclin, might be an alternative therapy for PPH, selectively acting on the pulmonary vascular bed through ventilation-matched alveolar deposition of the ...

Patients with pulmonary atresia and major aortopulmonary collateral arteries (MAPCAs) may be at risk for both ventilatory impairment and abnormal pulmonary circulation after definitive surgery. We measured the ventilatory response to exercise in 16 patients with MAPCAs after definitive surgery (group A) and compared the results with those in 16 ...

BACKGROUND: Patients with precapillary pulmonary hypertension (PH) exhibit a poor exercise capacity due to an impaired vasodilatory response of their pulmonary arteries. By causing the pulmonary artery to dilate, inhaled nitric oxide (NO) may allow an increase in exercise capacity in patients with PH. METHODS AND RESULTS: On 2 separate ...

During the past half-century, many studies have investigated the correlation of exercise tolerance to routine lung function in patients with obstructive pulmonary disease. In virtually all of these studies, the degree of airway obstruction was assessed in terms of forced expiratory volume in 1 s (FEV1) and forced vital capacity ...

STUDY OBJECTIVES: Diffusion impairment and reduced performance in cardiopulmonary exercise testing (CPX) have been found in patients after heart transplantation. The pathogenesis of these abnormalities is unclear. In particular, the contribution of pulmonary interstitial changes has not yet been verified. DESIGN: We analyzed pulmonary function tests, high-resolution CT (HRCT), echocardiography, ...

OBJECTIVES: Hypoxaemia occurring during haemodialysis has long been known. Several mechanisms in the pathogenesis have been proposed. The present study was conducted to test whether changes in pulmonary alveolar permeability were among the operating mechanisms. MATERIALS AND METHODS: Twenty haemodialysis patients (12 male, 8 female) were included in the study. ...

Furosemide premedication of horses 4 h prior to exercise significantly attenuates exercise-induced pulmonary capillary hypertension which may help diminish the severity of exercise-induced pulmonary haemorrhage. As pulmonary hemodynamic effects of furosemide may be mediated via a reduction in plasma volume (which is most pronounced 15-30 min postfurosemide administration, with plasma ...

BACKGROUND: Nitric oxide (NO) is present in exhaled breath and produced by the pulmonary vascular endothelium as a potent vasodilator. Exercise is normally associated with pulmonary vasodilatation and a decrease in pulmonary vascular resistance to accommodate the increase in cardiac output. If production of NO is impaired in patients with ...

OBJECTIVE: To examine the kinetics of successful nitric oxide (NO) withdrawal in vivo and in vitro. DESIGN AND SETTING: Prospective study in a university pediatric intensive care ward and research laboratory. PATIENTS AND MATERIALS: Nineteen patients with acute respiratory distress syndrome (ARDS) or persistent pulmonary hypertension of the newborn (PPHN). ...

BACKGROUND: Inhalation of nitric oxide with oxygen could be a promising treatment in patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension. However, the current methods of delivery of NO are cumbersome and unsuitable for long term use. The present study was undertaken to investigate the safety and efficacy ...

BACKGROUND: Pectus excavatum is a congenital chest abnormality which may become more marked during childhood and teenage growth. Young teenagers with severe PE deformities often become short of breath during strenuous exercise and complain of becoming easily fatigued. The pathophysiologic effects of PE remain controversial because they have been difficult ...

Surgical repair of tetralogy of Fallot (TOF) with reconstruction of the right ventricular (RV) outflow tract invariably results in pulmonary regurgitation. Chronic pulmonary regurgitation has been associated with RV dysfunction and decreased exercise performance. The present study assessed the influence of pulmonary valve replacement (PVR) for severe pulmonary regurgitation after ...

OBJECTIVE: To clarify the effects of lung volume reduction surgery (LVRS) on cardiopulmonary circulation during exercise in comparison with pulmonary lobectomy for lung cancer. SUMMARY BACKGROUND DATA: LVRS improves pulmonary function and dyspnea symptoms acutely in selected patients with heterogeneous emphysema. However, there are few data concerning the effects of ...

OBJECTIVE: The aim of this study was to evaluate the exercise tolerance by expired gas analysis during stress test in patients with Systemic Sclerosis (SSc). METHODS: Eighteen women (mean age 48.56+/-12.48 years) affected by SSc were studied. A complete echocardiographic examination including pulmonary artery systolic pressure estimation, pulmonary function tests, ...

To determine whether upright bicycle exercise could provide useful information about disabling exertional dyspnea in the absence of severe abnormalities (as shown by traditional testing methods), we evaluated 13 such patients. There were 3 men and 10 women with a mean age of 49+/-15 (SD) years. We used pulmonary artery ...

A total of 23 of the 40 patients who had angiographically proven pulmonary embolism and who had initially been randomized to an IV infusion of heparin (n = 11) or a thrombolytic agent (urokinase or streptokinase, n = 12) were restudied after a mean follow-up of 7.4 years to measure ...

OBJECTIVE: Exercise tolerance is often reduced in patients with systemic lupus erythematosus (SLE). Mechanisms have been proposed but the underlying causes have not yet been elucidated. The study of pulmonary gas exchange during exercise may be helpful in revealing circulatory, ventilatory, and metabolic abnormalities. We hypothesized that in SLE, exercise ...

OBJECTIVES: This study was undertaken to investigate the relationship between pulmonary hypertension and exercise performance in patients with heart failure. BACKGROUND: The exercise capacity of patients with heart failure is frequently reduced. Pulmonary hypertension may contribute to this exercise intolerance by impairing blood flow through the pulmonary circulation. METHOD: Three ...

The use of LVADs as a bridge to heart transplantation is increasing steadily as more surgical centers add this effective strategy for end-stage heart failure patients. Fundamental exercise physiology in the presence of LVADs has been described previously, and data is available that supports the safety and efficacy of exercise ...

Both pulmonary function and respiratory muscle strength decrease following exercise in healthy humans. The alterations in respiratory muscle are not the same following exercise and voluntary isocapnic hyperpnea that simulates that exercise. Therefore, in this study we measured pulmonary and respiratory muscle function following maximal exercise or hyperpnea that simulated ...

Immature foxhounds underwent 55% lung resection by right pneumonectomy (n = 5) or thoracotomy without pneumonectomy (Sham, n = 6) at 2 mo of age. Cardiopulmonary function was measured during treadmill exercise on reaching maturity 1 yr later. In pneumonectomized animals compared with Sham animals, maximal oxygen uptake, ventilatory response, ...

It has been suggested that the increase in PO(2) observed with nitric oxide (NO) should be enhanced by the addition of a vasoconstrictor agent. The vasoconstrictor used in combination with NO should mimic or enhance hypoxic vasoconstriction. The aim of this study was to evaluate the respiratory and hemodynamic effects ...

Several studies have reported a reduced pulmonary diffusion capacity for carbon monoxide after total body irradiation (TBI) and/or high-dose chemotherapy (HDCT) and autologous peripheral blood progenitor transplantation (APBPC). The present study describes the oxygenation of arterial plasma (paO2), the maximum exercise capacity (Wmax) and maximum oxygen transport (VO2max) before and ...

This study was carried out to examine changes in pulmonary vascular resistance (PVR) induced by moderate and strenuous exercise; the objective being to understand why pulmonary artery blood pressure of exercising horses increases progressively as work intensity increases. Pulmonary arterial and wedge pressures (referenced at the point of the left ...

To investigate the gas exchange response during exercise in horses with mild bronchiolitis (MB), we studied 7 Standardbred trotters. In order to determine pulmonary gas exchange and red cell volume in relation to bodyweight (CV/BW), submaximal graded exercise tests were performed. VO2 was monitored from an open bias flow system ...

BACKGROUND: Treatment of patients with secondary pulmonary hypertension has been unsatisfactory. OBJECTIVE: To describe exercise capacity, functional class, and hemodynamic variables after long-term intravenous infusion of prostacyclin in patients with secondary pulmonary hypertension. DESIGN: Case series. SETTING: Academic referral center. PATIENTS: 33 patients with secondary, precapillary pulmonary hypertension (New York ...

Changes in pulmonary circulation caused by muscular exercise and body position are usual in daily life. By using first-pass radiocardiography and fractal analysis, pulmonary circulation in man was evaluated at rest and during muscular exercise. At rest, pulmonary circulation was heterogeneous as described by the relative dispersion (which is the ...

Pulmonary function abnormalities after exercise are suggestive of pulmonary edema; however, radiographic evidence is lacking. Well-trained cyclists were studied to determine whether there is radiographic evidence of pulmonary edema after endurance exercise (cycling distance 5.3-131.5 km) at altitude. Chest radiographs obtained before exercise were coded for later interpretation. Films obtained ...

Pulmonary function tests, bronchoalveolar lavages, and venous blood samplings were performed 24 hours before and one hour after a standardized strenous treadmill exercise test on six horses suffering from chronic obstructive pulmonary disease (COPD) in clinical remission. Pulmonary function test consisted of the measurement of the mechanics of breathing and ...

This paper reviews recent evidence of the effect of intratracheal hyaluronan (HA) to limit the induction of experimental emphysema in hamsters. Experimental emphysema was induced by both neutrophil and pancreatic elastase instilled intratracheally. Emphysema was quantified anatomically by measurement of alveolar mean linear intercept. Hyaluronidase, instilled intratracheally, enhanced the induction ...

OBJECTIVE: To compare laryngoscopically observed changes in the larynx during exercise in persons with exercise-induced laryngomalacia (EIL) with changes in asymptomatic control subjects. STUDY DESIGN: Clinical study using a standardized exercise protocol. METHODS: Subjects exercised on an incremental ergometer: videotaped recordings of the larynx were obtained through the entire exercise; ...

Chest wall-restrictive loading reduces a person's ability to expand the chest wall during inhalation and results in decrements in lung capacities, resting pulmonary function, and ultimately, exercise performance. Chest wall restriction is observed in some forms of skeletal and pulmonary diseases (e.g., scoliosis) as well as in occupational situations (e.g., ...

Cardiopulmonary exercise testing is a useful noninvasive tool to assess physiological changes associated with exercise. Developing noninvasive methods to assess the severity of cardiopulmonary disorders, as well as the response to therapeutic interventions, is useful in conditions, such as primary pulmonary hypertension, in which invasive procedures carry significant risks. The ...

BACKGROUND: In cor pulmonale associated with severe chronic obstructive pulmonary disease (COPD), disturbances of pulmonary microcirculation may contribute significantly to hypoxemia, pulmonary hypertension, and exercise intolerance. OBJECTIVE: It was tested whether reduction of blood viscosity induced by repetitive hemodilution might improve pulmonary hemodynamics and oxygen uptake. METHODS: Seven patients with ...

PURPOSE: The purpose of this study was to determine the effects of repeated heavy exercise on postexercise pulmonary diffusing capacity (DL) and the development of exercise induced arterial hypoxemia (EIH). METHODS: 13 endurance-trained, male athletes (age = 27+/-3 yr, height = 179.6+/-5.0 cm, weight = 71.8+/-6.9 kg, VO2max = 67.0+/-3.6 ...

OBJECTIVE: The purpose of this study was to quantify the heterogeneous distribution of a carbon particle radioaerosol in the lungs of patients with pulmonary emphysema using single-photon emission computed tomography (SPECT) and fractal analysis. SUBJECTS AND METHODS: Ventilation SPECT was performed on 19 patients with pulmonary emphysema, seven patients with ...

STUDY OBJECTIVES: To clarify the effects of lung volume reduction surgery (LVRS) on pulmonary hemodynamics in severe emphysema and to evaluate the role of pulmonary circulation in the increased exercise performance after LVRS. DESIGN: In eight male patients with severe emphysema, we measured pulmonary artery (Ppa) and occlusion (Pop) pressures ...

BACKGROUND: Patients with chronic heart failure show impairment of ventilatory efficiency, defined as the relation between ventilation and carbon dioxide output. It is caused by ventilation of excess physiologic dead space. We hypothesized a role of active vasoconstriction in the increase of physiologic dead space, presumed to lead to alveolar ...