Exertional dyspnoea in cardiorespiratory disorders: the clinical use of cardiopulmonary exercise testing

Abstract

@ERSpublicationsA series of articles on exertional dyspnoea in cardiorespiratory disorders begins in the European Respiratory Review http://ow.ly/fLT0300uHgwIs dyspnoea worth documenting and accurately assessing? The answer is undoubtedly yes, for at least the following reasons. 1) Activity-related dyspnoea is usually the earliest and most troublesome complaint for which patients with cardiopulmonary diseases seek medical attention. 2) This symptom progresses relentlessly as the underlying disease advances, leading invariably to avoidance of activity with consequent skeletal muscle deconditioning and an impoverished quality of life. 3) It is estimated that up to a quarter of the general population and half of severely ill patients are affected by it. 4) Dyspnoea is also an important predictor of quality of life, exercise tolerance and mortality in various conditions. In patients with chronic obstructive pulmonary disease (COPD), it has been shown to be a better predictor of mortality than forced expiratory volume in 1 s. In patients with heart disease referred for clinical exercise testing, it is a better predictor of mortality than angina. 5) Dyspnoea is also associated with decreased functional status and worse psychological health in older individuals living at home. 6) It is also a factor in the low adherence to exercise training programmes in sedentary adults and in patients with COPD. 7) The effective management of exertional dyspnoea remains a major challenge for caregivers and modern treatment strategies that are based on attempts to reverse the underlying chronic condition are only partially successful [1][2][3][4][5][6][7].The perception of dyspnoea involves the integration of afferent and efferent inputs at a cortical level and is modulated by affective, emotional and behavioural components. The recent statements of the American Thoracic Society (ATS) [8] and European Respiratory Society [1] have underlined the multidimensional nature of dyspnoea which comprises three major dimensions: 1) the sensory-perceptual domain, 2) the affective distress and 3) the symptom impact or burden.Dyspnoea is a complex, multifaceted and highly personalised sensory experience, the source and mechanisms of which are incompletely understood: there is no unique central or peripheral source of this symptom. The definition given by the latest ATS statement ("a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity") highlights the importance of the

Contrasting the physiological effects of heliox and oxygen during exercise in a patient with advanced COPD

“…The mechanisms orchestrating the ergogenic effect of heliox and oxygen breathing on exercise capacity were not limited to the alleviation of ventilatory constraints during exercise. The results from this case and other studies suggest that extrapulmonary improvements could potentially alleviate exercise induced-dyspnoea in patients with COPD [17, 18]. Furthermore, during heliox and oxygen breathing the patient exhibited improved respiratory and locomotor muscle metabolic condition as indicated by the smaller decrease in local muscle oxygenation that was accompanied by less lactic acidosis as compared with room air (figure 3).…”

What can we learn from pulmonary function testing in heart failure?

“…Therefore, when dyspnoea is not explained by pulmonary or cardiac investigations, it is reasonable to submit symptomatic patients to cardiopulmonary exercise testing (CPET). The importance of CPET has recently been summarized for cardiopulmonary as well as respiratory disorders . Here, we mainly emphasize that easily available PFT may be of added value in the functional characterization of patients with chronic HF with or without respiratory co‐morbidities.…”

“…For instance, a recent study demonstrated that in patients with mild COPD, parameters of CPET have a strong association with D LCO . Nevertheless, CPET parameters may provide important additional information in individual patients, and detailed recommendations for this test have been summarized elsewhere …”

Exercise Capacity Is Independent of Respiratory Muscle Strength in Patients with Chronic Heart Failure

“…In this study, we found that reduced exercise capacity in patients with CHF was associated with an increased level of dyspnea, independent of the number of comorbidities and the ejection fraction of the left ventricle. An increased level of dyspnea during exercise is the hallmark of exercise intolerance in patients with CHF [25,26]. Dyspnea is multidimensional and derives from interactions between several domains, including physiological, psychological, social, and environmental factors [27].…”