Similarity between predicted and obtained oxygen consumption during incremental cardiopulmonary exercise test in healthy men and chronic heart failure patients (original) (raw)
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European Heart Journal, 2005
Aims Predicting survival from peak exercise oxygen uptake (peak VO 2) in chronic heart failure (CHF) is hindered by its reduction if exercise duration is submaximal. The oxygen uptake efficiency slope (OUES) is a non-linear description of the ventilatory response to exercise, which has the potential to describe abnormalities even early in exercise. We evaluated the physiology of OUES and assessed its potential for prognostic information in patients with CHF. Methods and results Two hundred and forty-three patients with CHF (mean age 59 + 12 years) underwent cardiopulmonary exercise testing between May 1992 and July 1996. Mean peak VO 2 was 16.2 + 6.7 mL/kg/min, VE/VCO 2 slope 38 + 12.5, ventilatory anaerobic threshold 10.9 + 3.5 mL/kg/min, and OUES 1.6 + 0.7 L/min. The value for each variable fell across the New York Heart Association classes (P , 0.0001 by analysis of variance for each). When only the first 50% of each exercise test was used to calculate the variables, the value obtained for OUES changed the least (peak VO 2 25% difference and OUES 1% difference). After a median of 9 years of follow-up, 139 patients (57%) had died. Each of the exercise variables was a significant univariate predictor of prognosis but in a multivariable model, only OUES was identified as the sole significant independent prognostic variable. Conclusion OUES provides an effective, independent measure of pathological exercise physiology. Its numerical value is relatively insensitive to the duration of exercise data from which it is calculated. Its prognostic value seems to be stronger than the best available existing measures of exercise physiology.
A Simple Prediction Formula for Peak Oxygen Consumption in Subjects with Heart Failure
Journal of Cardiac Failure, 2010
Peak oxygen consumption (VO 2 ) is one of the strongest predictors of survival in patients with chronic congestive heart failure (CHF), but it is unavailable in most practices. Peak VO 2 < 14 mL/kg/min identifies patients who might benefit from referral to a specialized CHF center. Accordingly, the current study was undertaken to derive a prediction formula based on routine stress data obtained from patients referred for cardiopulmonary exercise tolerance testing (CPETT). Subsequently, the prediction formula was validated in a separate cohort of similar patients referred for CPETT at another institution. The derivation cohort consisted of 208 patients with a diagnosis of CHF with reduced systolic function (left ventricular ejection fraction < 40%) who underwent elective CPETT. A multiple linear regression analysis was performed on available treadmill testing variables. A simple prediction formula was derived: Predicted peak VO 2 ¼ 16.7 e 1.3 (sex) e 3.8 Â (New York Heart Association functional class) þ 0.04 Â (peak heart rate) þ 0.92 Â (estimated metabolic equivalents). The validation cohort consisted of 112 patients referred for CPETT at a different institution for the evaluation of advanced CHF. The predicted peak VO 2 as obtained by the prediction formula was compared to the actual peak VO 2 using a Pearson coefficient of correlation. The predicted peak VO 2 was well correlated with the actual peak VO 2 demonstrating a correlation coefficient of r ¼ 0.77 with a 95% confidence interval of (0.68e0.83). A simple prediction formula using four variables that are routinely obtained in standard exercise treadmill testing can identify patients in whom formal CPETT is advisable and facilitate early referral to specialized heart failure centers.
American Journal of Physical Medicine & Rehabilitation, 2012
Beckers PJ, Possemiers NM, Van Craenenbroeck EM, Van Berendoncks AM, Wuyts K, Vrints CJ, Conraads VM: Comparison of three methods to identify the anaerobic threshold during maximal exercise testing in patients with chronic heart failure. Am J Phys Med Rehabil 2012;91:148Y155. Objective: Exercise training efficiently improves peak oxygen uptake (V O 2 peak) in patients with chronic heart failure. To optimize training-derived benefit, higher exercise intensities are being explored. The correct identification of anaerobic threshold is important to allow safe and effective exercise prescription. Design: During 48 cardiopulmonary exercise tests obtained in patients with chronic heart failure (59.6 T 11 yrs; left ventricular ejection fraction, 27.9% T 9%), ventilatory gas analysis findings and lactate measurements were collected. Three technicians independently determined the respiratory compensation point (RCP), the heart rate turning point (HRTP) and the second lactate turning point (LTP2). Thereafter, exercise intensity (target heart rate and workload) was calculated and compared between the three methods applied. Results: Patients had significantly reduced maximal exercise capacity (68% T 21% of predicted V O 2 peak) and chronotropic incompetence (74% T 7% of predicted peak heart rate). Heart rate, workload, and V O 2 at HRTP and at RCP were not different, but at LTP2, these parameters were significantly (P G 0.0001) higher. Mean target heart rate and target workload calculated using the LTP2 were 5% and 12% higher compared with those calculated using HRTP and RCP, respectively. The calculation of target heart rate based on LTP2 was 5% and 10% higher in 12 of 48 (25%) and 6 of 48 (12.5%) patients, respectively, compared with the other two methods. Conclusions: In patients with chronic heart failure, RCP and HRTP, determined during cardiopulmonary exercise tests, precede the occurrence of LTP2. Target heart rates and workloads used to prescribe tailored exercise training in patients with chronic heart failure based on LTP2 are significantly higher than those derived from HRTP and RCP.
European Journal of Heart Failure, 2001
Ž. Ž. Background: Oxygen O uptake at peak exercise VO peak is an objective measurement of functional capacity in patients 2 2 Ž VO rt-slope after maximal and submaximal exercise was reduced in patients with severe exercise intolerance F s 9.3, 2. P-0.001 and F s 12.8, P-0.001, respectively. Conclusions: Early recovery O kinetics parameters after maximal and 2 submaximal exercise correlate closely with established indices of exercise capacity in patients with CHF and in healthy volunteers. These findings support the use of early recovery O kinetics after submaximal exercise testing as an index of 2 functional capacity in patients with CHF.
Brazilian Journal of Physical Therapy, 2019
Background: Cardiopulmonary exercise testing is the main tool assessing cardiorespiratory fitness. However, cardiopulmonary exercise testing devices are expensive and often cannot be used. Objective: The present study sought to develop cardiopulmonary exercise testing equations for estimating maximum oxygen uptake from ergometric testing combined with ventilometry. Methods: 181 volunteers of both sexes were submitted to cardiopulmonary exercise testing on treadmill using an incremental protocol. Volunteers were randomized into two groups: regression group: composed of 68 women with age 24.7±6.0 years and 54 men aged 21.5±3.9 years; and a cross-validation group composed of 29 women with mean age of 23.8±4.7 years and 30 men with a mean age of 23.1±4.4 years. The estimating equations were developed using multiple stepwise linear regressions; comparison of means was done using a t test and reliability assessed by Cronbach's alpha. Results: 8 independent variables exhibited a significant result for estimating VO 2max : minute ventilation (E) at second ventilatory threshold (VT-II): (E VT-II); heart rate at VT-II (HR VT-II); body mass (BM); body mass index (BMI); fat percentage (F%); age; sex; velocity at VT-II (Vel VT-II); test time of VT-II (T VT-II) and final test velocity (Vel final). Two equations presented more
Revista portuguesa de cardiologia : orgão oficial da Sociedade Portuguesa de Cardiologia = Portuguese journal of cardiology : an official journal of the Portuguese Society of Cardiology, 2011
A growing body of evidence shows the prognostic value of oxygen uptake efficiency slope (OUES), a cardiopulmonary exercise test (CPET) parameter derived from the logarithmic relationship between O(2) consumption (VO(2)) and minute ventilation (VE) in patients with chronic heart failure (CHF). To evaluate the prognostic value of a new CPET parameter - peak oxygen uptake efficiency (POUE) - and to compare it with OUES in patients with CHF. We prospectively studied 206 consecutive patients with stable CHF due to dilated cardiomyopathy - 153 male, aged 53.3±13.0 years, 35.4% of ischemic etiology, left ventricular ejection fraction 27.7±8.0%, 81.1% in sinus rhythm, 97.1% receiving ACE-Is or ARBs, 78.2% beta-blockers and 60.2% spironolactone - who performed a first maximal symptom-limited treadmill CPET, using the modified Bruce protocol. In 33% of patients an cardioverter-defibrillator (ICD) or cardiac resynchronization therapy device (CRT-D) was implanted during follow-up. Peak VO(2), p...