Heart rate recovery in pulmonary arterial hypertension: relationship with exercise capacity and prognosis.

Background: Delayed postexercise heart rate recovery (HRR) has been associated with disability and poor prognosis in chronic cardiopulmonary diseases. The usefulness of HRR to predict exercise impairment and mortality in patients with pulmonary arterial hypertension (PAH), however, remains largely unexplored.

Methods: Seventy-two patients with PAH of varied etiology (New York Heart Association classes I-IV) and 21 age- and gender-matched controls underwent a maximal incremental cardiopulmonary exercise test (CPET), with heart rate being recorded up to the fifth minute of recovery.

Effects of oxygen supplementation on cerebral oxygenation during exercise in chronic obstructive pulmonary disease patients not entitled to long-term oxygen therapy.

Background: The rate of change (Δ) in cerebral oxygenation (COx) during exercise is influenced by blood flow and arterial O(2) content (CaO(2)). It is currently unclear whether ΔCOx would (i) be impaired during exercise in patients with chronic obstructive pulmonary disease (COPD) who do not fulfil the current criteria for long-term O(2) therapy but present with exercise-induced hypoxaemia and (ii) improve with hyperoxia (FIO(2) = 0·4) in this specific sub-population.

Methods: A total of 20 non-hypercapnic men (FEV(1) = 47·2 ± 11·5% pred) underwent incremental cycle ergometer exercise tests under normoxia and hyperoxia with ΔCOx (fold-changes from unloaded exercise in O(2)Hb) being determined by near-infrared spectroscopy.

Constant work-rate test to assess the effects of intradialytic aerobic training in mildly impaired patients with end-stage renal disease: a randomized controlled trial.

Objective: To investigate if high-intensity constant work rate (CWR) would constitute a more appropriate testing strategy compared with incremental work rate (IWR) to assess the effectiveness of intradialytic aerobic training in patients with end-stage renal disease (ESRD).

Design: Randomized controlled trial.

Setting: Nephrology unit at the university hospital.

Skeletal muscle reoxygenation after high-intensity exercise in mitochondrial myopathy.

This study addressed whether O(2) delivery during recovery from high-intensity, supra-gas exchange threshold exercise would be matched to O(2) utilization at the microvascular level in patients with mitochondrial myopathy (MM). Off-exercise kinetics of (1) pulmonary O(2) uptake VO(2P) (2) an index of fractional O(2) extraction by near-infrared spectroscopy (Δ[deoxy-Hb + Mb]) in the vastus lateralis and (3) cardiac output (Q'(T)) by impedance cardiography were assessed in 12 patients with biopsy-proven MM (chronic progressive external ophthalmoplegia) and 12 age- and gender-matched controls. Kinetics of VO(2P) were significantly slower in patients than controls (τ = 53.

Neuromuscular electrical stimulation improves exercise tolerance in chronic obstructive pulmonary disease patients with better preserved fat-free mass.

Background: High-frequency neuromuscular electrical stimulation increases exercise tolerance in patients with advanced chronic obstructive pulmonary disease (COPD patients). However, it is conceivable that its benefits are more prominent in patients with better-preserved peripheral muscle function and structure.

Objective: To investigate the effects of high-frequency neuromuscular electrical stimulation in COPD patients with better-preserved peripheral muscle function.

Effects of aerobic training during hemodialysis on heart rate variability and left ventricular function in end-stage renal disease patients.

Introduction: Decreased heart rate variability (HRV) in patients with end stage renal disease (ESRD) undergoing hemodialysis is predictive of cardiac death, especially due to sudden death.

Objective: To evaluate the effects of aerobic training during hemodialysis on HRV and left ventricular function in ESRD patients.

Methods: Twenty two patients were randomized into two groups: exercise (n = 11; 49.

Relationship between peripheral muscle structure and function in patients with chronic obstructive pulmonary disease with different nutritional status.

The purpose of this study was to investigate the relationships between peripheral muscle structure (mass) and function (strength, endurance, and maximal aerobic capacity) in patients with chronic obstructive pulmonary disease (COPD) with different nutritional states. Thirty-nine patients (31 male) with moderate-severe COPD (63.5 ± 7.

Relationship between work rate and oxygen uptake in mitochondrial myopathy during ramp-incremental exercise.

We determined the response characteristics and functional correlates of the dynamic relationship between the rate (Δ) of oxygen consumption (VO(2)) and the applied power output (work rate = WR) during ramp-incremental exercise in patients with mitochondrial myopathy (MM). Fourteen patients (7 males, age 35.4 ± 10.

Lung diffusing capacity relates better to short-term progression on HRCT abnormalities than spirometry in mild asbestosis.

Background: Pulmonary function tests (PFT), particularly spirometry and lung diffusing capacity for carbon monoxide (DL(CO) ), have been considered useful methods for the detection of the progression of interstitial asbestos abnormalities as indicated by high-resolution computed tomography (HRCT). However, it is currently unknown which of these two tests correlates best with anatomical changes over time.

Methods: In this study, we contrasted longitudinal changes (3-9 years follow-up) in PFTs at rest and during exercise with interstitial abnormalities evaluated by HRCT in 63 ex-workers with mild-to-moderate asbestosis.

Kinetics of skeletal muscle O2 delivery and utilization at the onset of heavy-intensity exercise in pulmonary arterial hypertension.

Impaired O(2) delivery relative to O(2) demands at the onset of exercise might influence the response profile of muscle fractional O(2) extraction (≅Δ[deoxy-Hb/Mb] by near-infrared spectroscopy) either by accelerating its rate of increase or creating an "overshoot" (OS) in patients with pulmonary arterial hypertension (PAH). We therefore assessed the kinetics of O(2) uptake [Formula: see text] Δ[deoxy-Hb/Mb] in the vastus lateralis, and heart rate (HR) at the onset of heavy-intensity exercise in 14 females with PAH (connective tissue disease, IPAH, portal hypertension, and acquired immunodeficiency syndrome) and 11 age- and gender-matched controls. Patients had slower [Formula: see text] and HR dynamics than controls (τ[Formula: see text] = 62.

Haemodynamic effects of proportional assist ventilation during high-intensity exercise in patients with chronic obstructive pulmonary disease.

Background And Objective: Proportional assist ventilation (PAV) has been proposed as a more physiological modality of non-invasive ventilation, thereby reducing the potential for deleterious cardio-circulatory effects during exercise, in patients with COPD. We therefore evaluated whether PAV modulates the kinetic and 'steady-state' haemodynamic responses to exercise in patients with moderate-to-severe COPD.

Methods: Twenty patients underwent constant-load (75-80% peak work rate) cycle ergometer exercise testing to the limit of tolerance (T(lim)), while receiving PAV or breathing spontaneously.

Bronchodilators accelerate the dynamics of muscle O2 delivery and utilisation during exercise in COPD.

Background: Expiratory flow limitation and lung hyperinflation promote cardiocirculatory perturbations that might impair O(2) delivery to locomotor muscles in patients with chronic obstructive pulmonary disease (COPD). The hypothesis that decreases in lung hyperinflation after the inhalation of bronchodilators would improve skeletal muscle oxygenation during exercise was tested.

Methods: Twelve non- or mildly hypoxaemic males (forced expiratory volume in 1 s (FEV(1))=38.

Kinetics analysis of muscle arterial-venous O(2) difference profile during exercise.

Muscle vascular dysfunction, a hallmark of chronic diseases such as heart failure and diabetes, impairs the matching of blood flow (Q(m)) to O(2) utilization (V(O(2m))) following exercise onset. One recently described consequence of this behavior is that arterial-venous O(2) difference [(a-v)(O(2)), the mirror image of muscle vascular oxygenation] transiently overshoots the subsequent steady-state and, in so doing, may provide important information regarding Q(m) versus V(O(2m)) dynamics. Using computer simulations, we tested the hypothesis that key parameters of the (a-v)(O(2)) overshoot - peak response, downward time constant (tau(D)), and total area - would relate quantitatively to Q(m) kinetics.

Effects of tiotropium and formoterol on dynamic hyperinflation and exercise endurance in COPD.

Background: It is currently unclear whether the additive effects of a long-acting beta(2)-agonist (LABA) and the antimuscarinic tiotropium bromide (TIO) on resting lung function are translated into lower operating lung volumes and improved exercise tolerance in patients with chronic obstructive pulmonary disease (COPD).

Methods: On a double-blind and cross-over study, 33 patients (FEV(1) = 47.4 +/- 12.

Effects of hyperoxia on the dynamics of skeletal muscle oxygenation at the onset of heavy-intensity exercise in patients with COPD.

This study addressed whether hyperoxia (HiOX=50% O2), compared to normoxia, would improve peripheral muscle oxygenation at the onset of supra-gas exchange threshold exercise in patients with chronic obstructive pulmonary disease (COPD) who were not overtly hypoxemic (resting Pa O₂> 60 mmHg ). Despite faster cardiac output and improved blood oxygenation, HiOX did not significantly change pulmonary O2 uptake kinetics ( VO₂p ). Surprisingly, however, HiOX was associated with faster fractional O2 extraction ( approximately Delta[deoxy-Hb+Mb] by near-infrared spectroscopy) (p<0.

Influence of respiratory pressure support on hemodynamics and exercise tolerance in patients with COPD.

Inspiratory pressure support (IPS) plus positive end-expiratory pressure (PEEP) ventilation might potentially interfere with the "central" hemodynamic adjustments to exercise in patients with chronic obstructive pulmonary disease (COPD). Twenty-one non- or mildly-hypoxemic males (FEV(1) = 40.1 +/- 10.

Microvascular oxygen delivery-to-utilization mismatch at the onset of heavy-intensity exercise in optimally treated patients with CHF.

Impaired muscle blood flow at the onset of heavy-intensity exercise may transiently reduce microvascular O(2) pressure and decrease the rate of O(2) transfer from capillary to mitochondria in chronic heart failure (CHF). However, advances in the pharmacological treatment of CHF (e.g.

Respiratory muscle function and exercise intolerance in heart failure.

Inspiratory muscle weakness (IMW) is prevalent in patients with chronic heart failure (CHF) caused by left ventricular systolic dysfunction, which contributes to reduced exercise capacity and the presence of dyspnea during daily activities. Inspiratory muscle strength (estimated by maximal inspiratory pressure) has independent prognostic value in CHF. Overall, the results of trials with inspiratory muscle training (IMT) indicate that this intervention improves exercise capacity and quality of life, particularly in patients with CHF and IMW.

Heliox improves oxygen delivery and utilization during dynamic exercise in patients with chronic obstructive pulmonary disease.

Rationale: Normoxic heliox (mixture of 79% He and 21% O(2)) may enhance exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). It remains to be determined whether part of these beneficial effects could be ascribed to increased O(2) delivery (O(2)DEL) to locomotor muscles.

Objectives: To investigate the effects of heliox on peripheral O(2)DEL and utilization during exercise in moderate to severe COPD.

Inspiratory resistive loading after all-out exercise improves subsequent performance.

We have previously shown that post-exercise inspiratory resistive loading (IRL) reduces blood lactate ([Lac(b)(-)]). In this study, we tested the hypothesis that IRL during recovery could improve subsequent exercise performance. Eight healthy men underwent, on different days, two sequential 30-s, cycle ergometer Wingate tests.

Asbestos-related disease: progression of parenchymal abnormalities on high-resolution CT.

Purpose: To evaluate the changes over time in the pattern and extent of parenchymal abnormalities in asbestos-exposed workers after cessation of exposure and to compare 3 proposed semiquantitative methods with a careful side-by-side comparison of the initial and the follow-up computed tomography (CT) images.

Materials And Methods: The study included 52 male asbestos workers (mean age+/-SD, 62.2 y+/-8.