Principles of exercise testing and interpretation wasserman pdf cpx athlete
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- Assessing Exercise Limitation Using Cardiopulmonary Exercise Testing
- Assessing Exercise Limitation Using Cardiopulmonary Exercise Testing
- Anaerobic threshold, is it a magic number to determine fitness for surgery?
Made with FlippingBook. Principles of exercise testing and interpretation: including pathophysiology and clinical applications. Philadelphia: Lippincott Williams andWilkins; Impact of different diagnostic criteria on the prevalence and prognostic significance of exertional oscillatory ventilation in patients with chronic heart failure. Eur J Cardiovasc Prev Rehabil.
Assessing Exercise Limitation Using Cardiopulmonary Exercise Testing
Use of the Wasserman equation in optimization of the duration of the power ramp in a cardiopulmonary exercise test: a study of Brazilian men. Seabra 1. Carvalho 1. This study aimed to analyze the agreement between measurements of unloaded oxygen uptake and peak oxygen uptake based on equations proposed by Wasserman and on real measurements directly obtained with the ergospirometry system.
Both groups performed CPET on a cycle ergometer with a ramp-type protocol at an intensity that was calculated according to the Wasserman equation. In the HG, there was no significant difference between measurements predicted by the formula and real measurements obtained in CPET in the unloaded condition.
In the CG, there was a significant difference of The Wasserman formula does not appear to be appropriate for prediction of functional capacity of volunteers. Therefore, this formula cannot precisely predict the increase in power in incremental CPET on a cycle ergometer. Key words: Wasserman equation; Cardiopulmonary exercise test; Coronary artery disease; Cardiovascular diagnostic techniques. The cardiopulmonary exercise test CPET has greatly changed the approach to functional evaluation by relating physical fitness and physiological parameters to the underlying metabolic substrate and by providing highly reproducible descriptors of effort capacity.
The CPET provides an accurate and objective measurement of functional capacity and of the integrity of the cardiovascular and respiratory systems. Therefore, the CPET has been indicated for assessment of functional capacity in high-performance athletes, for diagnostic purposes, and for evaluation of pharmacological or non-pharmacological therapies, preoperative risk, and for risk stratification.
The CPET is considered to be the most accurate method for assessment of aerobic power. However, different values may be obtained for the same individual when different modalities of the test are used 3 , 4. From a methodological point of view, two aspects crucially interfere with the quality of the test and the reproducibility of the response of the variables: the type of protocol and the duration of the effort tests.
Ramp protocols have become popular because they permit individualized tests. This is possible because load increment occurs constantly and continuously at a rate that can be individualized according to the capacity of the individual 5 - 8.
This equation is used for the choice of progressive load increment on a cycle ergometer during the CPET, and is applied to healthy individuals and to those with ischemic myocardial disease. This practice is based on the search for a less empirical and subjective manner of choosing the intensity of the power ramp to be applied to incremental effort tests on a cycle ergometer.
Elaboration of a formula for the calculation of load increment in a ramp-type incremental CPET by Wasserman et al. However, in many cases, a simple estimate of the power increment according to this formula can underestimate or overestimate the real functional capacity of a healthy individual or a patient.
Marked characteristics of health status, as well as disease status, directly interfere with the performance and homeostasis of the cardiopulmonary and musculoskeletal systems during exercise.
We studied a sample of apparently healthy sedentary males and a sample of sedentary males with coronary artery disease CAD. Two groups of sedentary males were selected. For inclusion in the study, all of the subjects were submitted to clinical evaluation and to a resting electrocardiogram to exclude asymptomatic heart disease or a history of cardiac or pulmonary disease or any orthopedic limitation. The other group was the coronary artery disease group CG. All of the patients had been clinically stable for at least the last 3 months, with optimized pharmacological treatment and no indication of new revascularization procedures.
All of the subjects gave written informed consent to participate. The formula proposed by Wasserman 9 was calculated for each individual for performance of the CPET as follows:. For subjects in the CG, this correction was made based on clinical evaluation and disease conditions, with an average 4. All of the subjects were submitted to a maximal CPET using a ramp-type incremental protocol.
The individuals performed dynamic physical effort in the sitting position on an electromagnetically braked cycle ergometer Corival , Lode BV, The Netherlands.
For all of the subjects, the beginning of the ramp exercise was preceded by 4 min of unloaded effort watts at a constant speed of 60 rotations per minute rpm. The anthropometric characteristics and risks factors of both groups are shown in Table 1. Previous events and interventions, distribution of the left ventricular ejection fraction, and medications used are shown in Table 2. The nonparametric Wilcoxon test was used for statistical analysis. The Wasserman formula 9 has been routinely used in our institution for the choice of progressive load increment power applied to the cycle ergometer during the CPET for healthy individuals and those with CAD.
Use of this method is based on an attempt to use a less empirical and subjective method of choosing the intensity of the power ramp to be applied during incremental effort tests on a cycle ergometer. Tests of short duration with intense power increments generate an insufficient quantity of data, thus impairing their interpretation. In addition, a relatively large proportion of the energy that is generated in these tests is based on anaerobic sources.
This fact compromises the response of the O 2 transport variables and the quality and reliability of the exam because the individual may interrupt the test early because of muscle fatigue. Conversely, long tests with small power increments can prolong the period of effort. In these situations, measurements of O 2 transport at submaximal effort are also compromised because of early termination of the exam.
Some investigators have been searching for new methods to accurately estimate the cardiovascular functional reserve, using CPET individualized protocols capable of reaching the maximum aerobic power.
Myers et al. Using multivariable analysis, they observed that age and the responses to the questionnaire were able to predict exercise tolerance. They proposed a nomogram that predicted the peak metabolic equivalent and the ramp load increment on a treadmill.
In , another group studying patients with heart disease developed a new questionnaire based on daily life activities However, most of the studies published in the literature did not detail the choice of the protocol that was used for individualization and performance of the effort tests, as concluded by Huggett et al.
The first recommendation on the ideal duration of effort tests needed to reach maximum aerobic power was published in 3. This controversial study involved only five healthy male volunteers, who performed three incremental effort tests on a treadmill and three tests on a cycle ergometer. However, another two studies showed that untrained men and women who were submitted to protocols with a mean time to exhaustion of 6.
Kang et al. Incremental effort tests of short duration can be particularly appropriate for trained individuals because of a greater efficiency in the kinetics of oxygen transport However, these short duration protocols may not be appropriate for patients with cardiorespiratory dysfunction.
Agostoni et al. Therefore, the age of subjects in the HG was an average of 10 years less than that of subjects in the CG because most of the risk factors arterial hypertension, diabetes mellitus, and smoking excluded HG volunteers. The remaining anthropometric characteristics, including body mass and height, were similar in the two groups. This criterion was adopted because of the difficulty in finding sedentary men older than 40 years with no regular medications and without risk factors that were considered to be modifiable In this case, the formula overestimated the real capacity of an individual.
Because of this difference, the ability of the formula to predict power increment ramp is impaired. There are few data to compare with our results. This previous study also showed that the Wassermann equation may not be suitable in our population. Despite the presence of impaired cardiac function, subjects in the CG were unable to achieve maximum effort when the load increment indicated by the Wasserman formula 9 was applied.
Subjective adjustments were necessary according to the clinical conditions and degree of physical activity existing at the time of performing the CPET. The differences detected in the analysis of the CG were of greater magnitude than those in the HG.
Therefore, in the CG, the measurements that were predicted by the Wasserman equation always overestimated the real aerobic capacity of the individuals. This fact indicates the need to continue to use a correction factor for power increment ramp in subjects with CAD who are evaluated by a routine CPET.
Wasserman et al. However, our results suggest that there is variation related to the experimental design and the individual characteristics involved in the formula. When we compared the behavior of cardiorespiratory variables during the CPET, we demonstrated a difference in functional capacity between patients with CAD and healthy individuals. The beneficial effects of this class of medications on improvement of symptom-limited effort capacity have been well established.
These effects include a reduction in myocardial ischemia due to effort, an increase in the ischemic threshold, and an improvement in autonomic modulation 27 , A lower heart rate was observed in subjects in the CG during the rest phase and during the various effort phases unloaded, load increment, and peak effort compared with subjects in the HG, who did not use medications. According to Pearson et al.
Therefore, although there is evidence that muscle fatigue is also caused by neuromuscular mechanisms 33 , 34 , this reduced blood flow may explain, at least in part, early fatigue. For a prediction or estimation equation, understanding the structural and local characteristics of the population for which the equation is created or validated is important. As in other seminal studies 3 , 9 , our study has several limitations. Our sample size was small in both groups, but our strict selection criteria enabled the groups to be uniform.
The present study provides initial evidence that the Wasserman formula does not appear to be appropriate for prediction of functional capacity of Brazilian volunteers, regardless of whether they are apparently healthy or have CAD. Therefore, we cannot precisely predict the power increment ramp in incremental CPET on a cycle ergometer.
When healthy subjects are compared with those with CAD, the disagreement between measurements is much more marked in the latter than the former. J Am Coll Cardiol ; , doi: Clinical recommendations for cardiopulmonary exercise testing data assessment in specific patient populations.
Circulation ; , doi: Optimizing the exercise protocol for cardiopulmonary assessment. Maximal aerobic capacity testing of older adults: a critical review. Cardiopulmonary exercise testing and its application. Postgrad Med J ; , doi: Understanding the basics of cardiopulmonary exercise testing.
Mayo Clin Proc ; , doi: Myers J, Bellin D. Ramp exercise protocols for clinical and cardiopulmonary exercise testing. Sports Med ; , doi: Romer LM. Cardiopulmonary exercise testing in patients with ventilatory disorders. Editors , Sports and exercise physiology testing guidelines: exercise and clinical testing. London: Routledge;
Assessing Exercise Limitation Using Cardiopulmonary Exercise Testing
The clinical importance of cardiopulmonary exercise testing and aerobic training in patients with heart failure. Unfortunately, these systems are all negatively impacted in patients with heart failure HF , resulting in significantly diminished aerobic capacity compared with apparently healthy individuals. The values of several key variables obtained from CPX, such as peak oxygen consumption and ventilatory efficiency, are often found to be abnormal in patients with HF. In addition to the ability of CPX variables to acutely reflect varying degrees of pathophysiology, they also possess strong prognostic significance, further bolstering their clinical value. Once thought to be contraindicated in patients with HF, participation in a chronic aerobic exercise program is now an accepted lifestyle intervention.
Request PDF | Principles of exercise testing and interpretation: Including For comparison we used the Hansen-Wasserman's 6, 7 and the Fitness Registry and the individual's health condition and activity habit so that the duration of CPX was cortex to physical capacity in athletes and patients with chronic heart failure.
Anaerobic threshold, is it a magic number to determine fitness for surgery?
The committee aims to serve as a resource for consultative cardiovascular assessment of highly active individuals as well as a home for educational tools to aid in their assessment and management. The Cardiopulmonary Exercise Test Introduction Physical activity requires the integrated performance of cardiovascular, pulmonary, metabolic, and neuromuscular systems. The Cardiopulmonary Exercise Test CPET or CPX evaluates the concerted response of these systems during exercise and provides an assessment of each component required for exercise performance. In contrast to standard exercise test modalities, the defining element of CPET is the continuous measurement of ventilation and gas exchange. The relationship between oxygen consumption and carbon dioxide production and a vast array of non-invasive physiological parameters are used to determine the function of each component of physical exertion.
Download PDF. Abstract: In patients presenting cardiovascular, pulmonary, muscular and metabolic diseases, exercise testing continues to be a predictive and diagnosis source of information. Diagnosis and assessment of coronary artery disease known or suspected encompass clinical and risk factors evaluation and well-defined non-invasive and invasive tests.
The use of cardiopulmonary exercise testing CPET to evaluate cardiac and respiratory function was pioneered as part of preoperative assessment in the mid s. Surgical procedures have changed since then.
Cardiopulmonary Exercise Testing: Indications, Interpretation & Cases
Use of the Wasserman equation in optimization of the duration of the power ramp in a cardiopulmonary exercise test: a study of Brazilian men. Seabra 1. Carvalho 1. This study aimed to analyze the agreement between measurements of unloaded oxygen uptake and peak oxygen uptake based on equations proposed by Wasserman and on real measurements directly obtained with the ergospirometry system. Both groups performed CPET on a cycle ergometer with a ramp-type protocol at an intensity that was calculated according to the Wasserman equation. In the HG, there was no significant difference between measurements predicted by the formula and real measurements obtained in CPET in the unloaded condition. In the CG, there was a significant difference of
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