Exercise Intolerance in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is associated with symptoms of dyspnea and fatigue, which contribute to exercise limitation. The origins and significance of dyspnea and fatigue in PAH are not completely understood. This has created uncertainly among healthcare professionals regarding acceptable levels of these symptoms, on exertion, for patients with PAH. Dysfunction of the right ventricle (RV) contributes to functional limitation and mortality in PAH; however, the role of the RV in eliciting dyspnea and fatigue has not been thoroughly examined. This paper explores the contribution of the RV and systemic and peripheral abnormalities to exercise limitation and symptoms in PAH. Further, it explores the relationship between exercise abnormalities and symptoms, the utility of the cardiopulmonary exercise test in identifying RV dysfunction, and offers suggestions for further research

Defining the appropriate waiting time between multiple-breath nitrogen washout measurements

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Short term effects of exercise training on exercise capacity and quality of life in patients with pulmonary arterial hypertension: protocol for a randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>Advances in the understanding and management of pulmonary arterial hypertension have enabled earlier diagnosis and improved prognosis. However, despite best available therapy, symptoms of exertional dyspnoea and fatigue are commonly reported and result in a reduced capacity to perform daily activities and impaired quality of life. Exercise training has demonstrated efficacy in individuals with other respiratory and cardiovascular diseases. Historically, however, exercise training has not been utilised as a form of therapy in pulmonary arterial hypertension due to the perceived risk of sudden cardiac death and the theoretical possibility that exercise would lead to worsening pulmonary vascular haemodynamics and deterioration in right heart function. Now, with the advances in pharmaceutical management, determining the safety and benefits of exercise training in this population has become more relevant. Only three studies of supervised exercise training in pulmonary arterial hypertension have been published. These studies demonstrated improvements in exercise capacity and quality of life, in the absence of adverse events or clinical deterioration. However, these studies have not utilised an outpatient-based, whole body exercise training program, the most common format for exercise programs within Australia. It is uncertain whether this form of training is beneficial and capable of producing sustained benefits in exercise capacity and quality of life in this population.</p> <p>Design/Methods</p> <p>This randomised controlled trial will determine whether a 12 week, outpatient-based, supervised, whole body exercise training program, followed by a home-based exercise program, is safe and improves exercise capacity and quality of life in individuals with pulmonary arterial hypertension. This study aims to recruit 34 subjects who will be randomly allocated to the exercise group (supervised exercise training 3 times a week for 12 weeks, followed by 3 sessions per week of home exercise for 12 weeks) or the control group (usual medical care). Subjects will be assessed at baseline, 12 weeks and 24 weeks.</p> <p>Discussion</p> <p>This study will determine whether outpatient-based, whole body exercise training is beneficial and safe in individuals with pulmonary arterial hypertension. Additionally, this study will contribute to clinical practice guidelines for this patient population.</p> <p>Trial registration</p> <p>Australia and New Zealand Clinical Trials Register (ANZCTR): <a href="http://www.anzctr.org.au/ACTRN12609000502235.aspx">ACTRN12609000502235</a></p

Psychometric performance of the CAMPHOR and SF-36 in pulmonary hypertension

BACKGROUND: The Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) and the Medical Outcomes Study Short Form 36 (SF-36) are widely used to assess patient-reported outcome in individuals with pulmonary hypertension (PH). The aim of the study was to compare the psychometric properties of the two measures. METHODS: Participants were recruited from specialist PH centres in Australia and New Zealand. Participants completed the CAMPHOR and SF-36 at two time points two weeks apart. The SF-36 is a generic health status questionnaire consisting of 36 items split into 8 sections. The CAMPHOR is a PH-specific measure consisting of 3 scales; symptoms, activity limitations and needs-based QoL. The questionnaires were assessed for distributional properties (floor and ceiling effects), internal consistency (Cronbach's alpha), test-retest reliability and construct validity (scores by World Health Organisation functional classification). RESULTS: The sample comprised 65 participants (mean (SD) age = 57.2 (14.5) years; n(%) male = 14 (21.5%)). Most of the patients were in WHO class 2 (27.7%) and 3 (61.5%). High ceiling effects were observed for the SF-36 bodily pain, social functioning and role emotional domains. Test-retest reliability was poor for six of the eight SF-36 domains, indicating high levels of random measurement error. Three of the SF-36 domains did not distinguish between WHO classes. In contrast, all CAMPHOR scales exhibited good distributional properties, test retest reliability and distinguished between WHO functional classes. CONCLUSIONS: The CAMPHOR exhibited superior psychometric properties, compared with the SF-36, in the assessment of PH patient-reported outcome

Effects of High-Intensity Inspiratory Muscle Training Following a Near-Fatal Gunshot Wound

Background and Purpose: Severe injuries sustained during combat may classify individuals as undeployable for active service. It is imperative that every effort is made to optimize physical function following such injuries. Case Description: A 38-year-old man sustained a gunshot wound during armed combat. The bullet entered via the left axilla and exited from the right side of the abdomen, resulting in severe thoracic and abdominal injuries. Five months later, he continued to describe severe dyspnea on exertion. During a cardiopulmonary exercise test on a cycle ergometer, he achieved a maximum rate of oxygen uptake of 2,898 mL•min−1 (114% predicted) and maximum power of 230 W (114% predicted). His maximum forced inspiratory flow was 5.95 L•s−1, and inspiratory reserve volume at test end was ∼80 mL. The test was terminated by the patient due to dyspnea that was too severe to tolerate. Video fluoroscopy demonstrated impaired right hemidiaphragm function. The main goals of therapy were to reduce dyspnea on exertion and to enable return to full work duties. A program of high-intensity, interval-based threshold inspiratory muscle training (IMT) was undertaken. Outcomes: An average of 5 sessions of IMT were completed each week for 10 weeks. During a repeat cardiopulmonary exercise test, the patient achieved a similar power and maximum rate of oxygen uptake. His maximum forced inspiratory flow increased by 48% to 8.83 L•s−1, and he was limited by leg fatigue. Discussion: High-intensity IMT was safe and well tolerated. It was associated with improvements in maximum forced inspiratory flow and changed the locus of symptom limitation during high-intensity exercise from dyspnea to leg fatigue

Implications of exercise-induced pulmonary arterial hypertension

Purpose: To characterize the hemodynamic and ventilatory responses to exercise in a group of patients with unexplained dyspnea, increased risk for pulmonary arterial hypertension (PAH), and an elevated mean pulmonary artery pressure (mPAP; \u3e30 mm Hg) on exercise. Methods: A total of 37 symptomatic patients at risk of PAH and 20 healthy controls underwent a cardiopulmonary exercise test and were assessed for quality of life (QOL). Patients had a pulmonary artery catheter in situ during the exercise test. Results: Seventeen subjects had exercise-induced PAH (EIPAH), which we defined as mPAP \u3c= 25 mm Hg at rest, and mPAP \u3e 30 mm Hg and pulmonary artery wedge pressure \u3c20 mm Hg on exercise. These subjects had reduced peak exercise cardiac output (72% ± 19% predicted). Further, compared with matched controls, subjects with EIPAH had reduced peak oxygen consumption (1.2 ± 0.4 vs 1.7 ± 0.5 L·min-1, P \u3c 0.05), an elevated ventilatory equivalent for carbon dioxide (41.0 ± 7.3 vs 31.0 ± 2.9, P \u3c 0.05) and reduced end-tidal carbon dioxide tension (32.6 ± 3.6 vs 39.4 ± 2.7 mm Hg, P \u3c 0.05) at the anaerobic threshold. These exercise abnormalities were associated with impaired QOL (P \u3c 0.05). Conclusions: Elevated pulmonary artery pressure on exercise can be associated with hemodynamic and ventilatory abnormalities typical of PAH, along with impaired exercise capacity and reduced QOL