Symptoms

Apart from chest pain or dizziness, which usually prompt cessation of an exercise test, the majority of normal subjects report that breathlessness or leg discomfort are the major causes of quitting 138 . Several psychophysical rating scales have been used to quantify the intensity of symptom perceptions. The Borg scale is a ratio scale that incorporates verbal descriptors assigned to specific scale values. With the 6-20 scale 139 , a symptom-limited maximal effort rating of perceived exertion...

Limitations to ventilation

At maximal exercise, there is little evidence of mechanical limitation to ventilation in normal, young moderately fit subjects 72, 73 . Such subjects typically have a considerable breathing reserve (BR), calculated as where MVV is the maximal voluntary ventilation and VE,max is the maximum exercise Ve e.g. 1, 2 . The VE,max actually attained during exercise is substantially less than the subject's MVV. Furthermore, the spontaneously generated expiratory flow-volume curve does not normally...

Future directions

It is likely that the scope of exercise testing in clinical practice will extend beyond diseases such as COPD, ILD, PPH and CHF in the future to include diseases whose prevalence is increasing and which often express exercise intolerance, such as the metabolic syndrome 55 . It is also likely that exercise testing will assume greater Table 4. - Indications for cardiopulmonary exercise testing in clinical practice Table 4. - Indications for cardiopulmonary exercise testing in clinical practice...

Diagnosis of exerciseinduced asthma and EIB

Exercise-induced asthma (EIA) is a condition with EIA symptoms, whereas EIB can be understood as the demonstration of EIB by lung function measurements after an exercise test or spontaneous exercise. EIA and EIB can be diagnosed in several ways. The optimal way is to employ a standardised exercise test and measure lung function before and after exercise. Standardisation is particularly important in the follow-up of EIA over time, when comparing different individuals and in epidemiological...

Equipment and measurements

Two modes of exercise are commonly employed in cardiopulmonary exercise tests cycle ergometer and treadmill. Cycle ergometer. For laboratory exercise testing, there are several advantages to using a cycle ergometer. The cycle ergometer is generally cheaper and requires less space. It is also less prone to introducing movement or noise artefacts into measurements blood pressure auscultation, for example, is generally easier. An important advantage is that the rate at which external work is...

Pulmonary vascular diseases

Pulmonary hypertension is defined as a mean Ppa of > 25 mmHg at rest or > 30 mmHg during exercise 114 . Pulmonary hypertension is consistently associated with reduced exercise capacity 115-117 . It has recently been shown that peak Vo2 correlates significantly with New York Heart Association symptom class in patients with primary pulmonary hypertension 117 . Typical abnormalities in the cardiopulmonary responses to exercise in this condition are well described 118 . Pulmonary hypertension...

Differential diagnosis of EIB

There are several important differential diagnoses relating to EIA or EIB in children and adolescents, and particularly in adolescents who participate in sports. One frequent differential diagnosis is exercise-induced inspiratory stridor or exercise-induced vocal cord dysfunction 28 . The symptoms are inspiratory stridor occurring during maximum exercise, which ceases when exercise is terminated unless hyperventilation is maintained. During exercise testing, audible inspiratory sounds can be...

Muscle testing

Assessment of skeletal muscle function contributes significantly to the evaluation of impairment, prognosis and effects of interventions in patients with COPD and congestive heart failure 64 , sarcoidosis 65 and cystic fibrosis 66 . Skeletal muscle function is an independent marker of disease severity 67 , since it contributes to the above-mentioned clinically relevant issues. Muscle function assessment enables diagnosis of muscle weakness, and thus the indication for rehabilitation. Indeed,...

Powerduration relationship

This is deserving of comment in the context of CPET, because of the growing popularity of timed field tests 156 and the high-intensity symptom-limited constant-WR test in interventional and prognostic contexts reviewed in 68 . The power-duration relationship is well described by a hyperbolic function, both in healthy subjects (fig. 1a) e.g. 16 and in patients with COPD 157, 158 where tlim is the tolerable duration, CP is the critical power (i.e. the asymptote for this hyperbolic relationship),...

References

Wasserman K, Sue DY, Casaburi R, Moricca RB. Selection criteria for exercise training in pulmonary rehabilitation. Eur Respir J 1989 2 Suppl. 7, 604s-610s. 2. McGavin CR, Gupta SP, McHardy GJR. Twelve-minute walking test for assessing disability in chronic bronchitis. BMJ 1976 1 822-823. 3. Morgan AD, Peck DF, Buchanan DR, McHardy GJR. Effect of attitudes and beliefs on exercise tolerance in chronic bronchitis. BMJ 1983 286 171-173. 4. Swinburn CR, Wakefield JM, Jones PW. Performance,...

Exercise testing in the prognostic evaluation of patients with lung and heart diseases

Dept of Clinical Medicine, Pulmonary Function Unit, University of Rome La Sapienza, Rome, Italy. Correspondence P. Palange, Dept of Clinical Medicine, Pulmonary Function Unit, University of Rome La Sapienza'', 00185 Rome, Italy. Fax 39 6494021 E-mail paolo.palange uniroma1.ie Exercise tolerance is a well recognised predictor of mortality in healthy subjects 1-3 , as well as in patients with pulmonary and cardiovascular disease 4 . In clinical practice, physiological measurements obtained during...

Restrictive lung diseases

Restrictive lung disorders are also characterised by the inability to expand Vt appropriately during the increased metabolic demand of exercise. Lung parenchymal diseases, neuromuscular disorders, chest wall restriction and pulmonary resection represent the most common restrictive disorders. The present chapter focuses on the interstitial lung diseases ILDs . These represent a broad and heterogeneous group of disorders that display common patterns of ventilatory response to exercise. As in...

Available tests and how to choose the appropriate one

The gold standard in exercise testing is the laboratory-based maximal incremental test. Since it spans the entire range of tolerable work-rates, the incremental exercise test is the test of choice for 1 assessment of impaired exercise capacity 2 investigation into the factors limiting exercise performance 3 assessment of risk of participation in exercise programmes and 4 prescription of exercise training. For all of these indications, incremental exercise testing is necessary, as it provides...

CPET indices of relevance for cardiac patients

Several indices of response to incremental tests, either singly or in combination, are relevant in cardiac patients. Vo2,peak is the most well-known and widely used variable obtained from a CPET. indeed, as it is often the only test variable that clinicians ask for, this does not help in promoting the popularity of CPET. In 1985, Weber and Janicki 27 reported a still frequently utilised classification of heart failure severity, based on Vo2,peak. The value of Vo2,peak is reported as normalised...

PaO2 and PaCO2 and the alveolararterial PO2 difference

In the steady-state of moderate intensity exercise, Pa,cO2 is normally regulated at, or close to, resting levels, except if the subject has acutely hyperventilated prior to the exercise, in which case the hyperventilation typically subsides as the exercise develops and the Pa,co2 rises back to the normal control level. During rapid-incremental exercise, however, Pa,cO2 does evidence a small but significant increase 2, 79 . This is because the time constant of response is slightly larger for VE...

Ventilatory equivalent for CO2

The ventilatory equivalent for CO2 VE- VCO2 during exercise, for example at its nadir or at 0L, has also been shown to have prognostic value during exercise for further details see Chapter 10 . As described in Chapter 2, during incremental exercise VE-VCO2 declines hyperbolically with respect to VCO2 to attain its minimum at or above the 0L, prior to increasing as respiratory compensation for the metabolic acidosis develops. In healthy young adults, the minimum VE-VCO2 is in the region of 23-25...

Oxygen uptake

Vo2 Time Constant

In order to understand the profiles of response of a particular variable of interest during exercise, it is useful to use the expected or normal kinetic profile as the frame of reference, based upon the known or postulated underlying control mechanism. Consequently, the expected temporal response profile of Vo 2 to a ramp-type incremental exercise test will reflect the fact that the sub-maximal muscle VO2 is controlled by the turnover of the high-energy phosphate pool 7, 27-29 . This is known...

Carbon dioxide output

Maximal Exercise Test Vo2 Co2

Pulmonary Vco2 also has important implications for the integrated systemic response to exercise. For example, taken with Vo2 in the steady state, VCo provides important information regarding the substrate mixture undergoing catabolism. In addition, in the context of arterial blood-gas and acid-base homeostasis, VCo provides an important frame of reference for establishing the normality of the ventilatory response to exercise. Also, Vco2 is an essential determining factor for noninvasive 0L...

Ventilation and acidbase regulation during exercise

Although Pa,cO2 appears to be a regulated variable during moderate exercise in normal subjects, it must be reduced to provide the respiratory compensation that constrains the fall of pH at levels of exercise which induce metabolic acidosis with a consequently reduced arterial HCO3- . This compensatory decrease in Pa,cO2 is a result of carbon dioxide being washed-out of the body stores providing an additional source of expired carbon dioxide at high WRs. However, the standard...

VO2WR relationship

There are several quantifiable features of the VO2 response to incremental exercise that provide important clues to ascertaining why a subject may manifest exercise intolerance. The most obvious of these is the maximum Vo2 most usually inferred from VO2,peak , but additional submaximal indices may also be informative. Interpreting abnormalities in the Vo2 response to incremental exercise requires consideration of its determining variables, as characterised by the Fick Principle. For the body as...

Comparison of selfpaced and externally paced shuttle walking tests

Although the self- and externally paced SWTs are fundamentally different, attempts have been made to compare the two protocols. The original study describing the SWT included a comparison with the 6MWT 6 . The authors found that the distance completed in both tests was similar for the majority of patients, but that the pattern of response was different. More recently, Eiser et al. 73 compared the reliability, reproducibility and sensitivity to change of the 6MWT, 2MWT and ISWT in 57...

Endtidal PO2 and PCO2

The alveolar gas values determined at the end of an exhalation the end-tidal values are easy to measure but extremely difficult to interpret. During exhalation, PA,co2 continues to increase fig. 9 at a rate that is dependent on the mixed venous Pco2 Pn,co2 value and to a level that depends on the duration of the exhalation tE . Pet,co2 may, therefore, be considered to be the peak of the intra-breath oscillation of PA,co2 and Pa,co2 during the breathing cycle whereas the measured Pa,co2, usually...

ATP the direct energy source for muscle contraction

While ATP is the obligatory energy resource for muscle contraction, its concentration in skeletal muscle is extremely small 5 mM-kg-1 sufficient in itself to sustain a high-intensity activity for only a few seconds. Despite this, its concentration does not decrease during dynamic exercise e.g. 6, 7 , except at extremely high work-rates WRs e.g. 8 , and not always then e.g. 6 . This is because the production rate of ATP is increased through the intensity-dependent contributions from aerobic and...

Limiting factors

On the basis of the contracting muscles apparently having a greater potential to accommodate blood flow than is actually achieved at maximum exercise, the output of the heart is considered to provide the more important cardiovascular limitation to exercise involving large muscle mass in normal subjects e.g. 90, 92, 106, 107 . However, even in trained athletes during maximal exercise at very high rates of oxygen utilisation, not all oxygen offered to muscles can be extracted. Interestingly, when...