Influence of the incremental step size in work rate on exercise response and gas exchange in patients with pulmonary hypertension

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Cardiopulmonary exercise testing (CPET) has become increasingly important as a routine procedure in daily clinical work. So far, it is generally ccepted that an individualized exercise protocol with exercise duration of 6 to 12 minutes is preferable to assess maximal exercise performance. The aim of this study was to compare an individualized NYHA adapted exercise protocol with a fixed standard protocol in patients with severe pulmonary arterial hypertension.

Twenty-two patients (17 female, 5 male; mean age 49 ± 14 yrs) underwent symptom limited CPET on a bicycle. On two consecutive days each subject performed a stepwise CPET according to a modified Jones protocol (16 Watt per minute stages) as well as an individualized NYHA adapted protocol with 5 or 10 Watt/min stages in a randomized order. Oxygen uptake at peak exercise (peakVO2) and anaerobic threshold (VO2AT), maximal ventilation (VE), breathing reserve (VE/MVV), ventilatory efficiency (VE vs. VCO2 slope), exercise time, maximal power and work rate were assessed and compared between both protocols.

Comparing both, adapted NYHA protocol and standardized Jones protocol, we found significant differences in maximal power(56.7 ± 19 W vs. 74 ± 18 W; p 0.001) and exercise time (332 ± 107 sec. vs. 248 ± 72 sec.; p 0.001). In contrast, no significant differences were obvious comparing both protocols concerning work rate, VE, VE/MVV, peakVO2, VO2AT and VE vs. VCO2 slope.

Variations of incremental step size during CPET significantly affect exercise time and maximal power, whereas relevant parameters for clinical judgement and prognosis such as oxygen uptake, ventilation and ventilatory efficiency remain unchanged. These findings have practical implications for the exercise evaluation of patients with pulmonary hypertension. To reach maximal results for ventilation, oxygen uptake and gas exchange an individualization of incremental step size appears not to be mandatory.



  1. Arena R, Myers J, Abella J, Peberdy MA, Bensimhon D, Chase P,Guazzi M: Development of a ventilatory classification systemin patients with heart failure. Circulation 007, 115:2410-7. Epub2007 Apr 23
  2. Weber KT, Kinasewitz GT, Janicki JS, Fishman AP: Oxygen utilizationand ventilation during exercise in patients with chroniccardiac ailure. Circulation 1982, 65:1213-1223.
  3. Mancini D, LeJemtel TH: Is ventilatory classification preferableto peak oxygen consumption for risk stratification in heartfailure? irculation 2007, 115:2376-8.
  4. Habedank D, Ewert R, Hummel M, Wensel R, Hetzer R, Anker SD:Changes in exercise capacity, ventilation, and body weightfollowing heart ransplantation. Eur J Heart Fail 2007, 9:310-6.Epub 2006 Oct 4.
  5. Kleber FX, Sabin GV, Winter UJ, Reindl I, Beil S, Wenzel M, FischerM, Doering W: Angiotensin-converting nzyme inhibitors inpreventing remodeling and development of heart failureafter acute myocardial infarction: results of the Germanmulticenter study of the effects of captopril n cardiopulmonaryexercise parameters (ECCE). Am J Cardiol 1997,80(3A):162A-167A.
  6. Mancini DM, Eisen H, Kussmaul W, Mull R, Edmunds LH Jr, WilsonJR: Value of peak xercise oxygen consumption for optimaltiming of cardiac transplantation in ambulatory patientswith heart failure. Circulation 1991, 83:778-786.
  7. Wensel R, Opitz CF, Anker D, Winkler J, Hoffken G, Kleber FX,Sharma R, Hummel M, Hetzer R, Ewert R: Assessment of survivalin patients with primary pulmonary hypertension: importanceof ardiopulmonary exercise testing. Circulation 2002,106:319-24.
  8. Kleber FX, Vietzke G, Wernecke KD, Bauer U, Opitz C, Wensel R,Sperfeld A, Glaser S: Impairment of entilatory efficiency inheart failure: prognostic impact. Circulation 2000, 101:2803-9.
  9. Gitt AK, Wasserman K, Kilkowski C, Kleemann T, Kilkowski A, BangertM, Schneider S, chwarz A, Senges J: Exercise anaerobicthreshold and ventilatory efficiency identify heart failurepatients for high risk of early death. Circulation 2002,106:3079-84.
  10. asserman , Karlman , Hansen , James E, Sue , Darryl Y, Stringer ,William W, Whipp , Brian J: Principles of Exercise Testing and Interpretation:Including Pathophysiology and linical Applications 4th edition. LippincottWilliams and Wilkins, US; 2004.
  11. Zhang YY, Johnson MC 2nd, Chow N, Wasserman K: Effect of exercisetesting protocol on arameters of aerobic function. MedSci Sports Exerc 1991, 23:625-30.
  12. Buchfuhrer MJ, Hansen JE, Robinson TE, Sue DY, Wasserman K,Whipp BJ: Optimizing the exercise rotocol for cardiopulmonaryassessment. J Appl Physiol 1983, 55:1558-64.
  13. Bentley DJ, McNaughton LR: Comparison of W(peak),VO2(peak) and the ventilation threshold rom two differentincremental exercise tests: relationship to endurance performance.J Sci Med Sport 2003, 6:422-35.
  14. Myers J, Buchanan N, Walsh D, Kraemer M, cAuley , Hamilton-Wessler M, Froelicher VF: Comparison of the ramp versusstandard exercise protocols. J Am Coll Cardiol 1991, 17:1334-42.
  15. Debigar─é┬® R, Maltais F, Mallet M, asaburi R, LeBlanc P: Influence ofwork rate incremental rate on the exercise responses inpatients with COPD. Med Sci Sports Exerc 2000, 32:1365-8.
  16. Simonneau G, aliè , Rubin LJ, Langleben D, Seeger W,Domenighetti G, Gibbs S, Lebrec D, Speich R, Beghetti M, Rich S, FishmanA: Clinical classification of pulmonary hypertension. J AmColl ardiol 2004, 43:5S-12S.
  17. Jones NL: Clinical exercise testing 3rd edition. Philadelphia: W.B.Saunders;1988.
  18. Whipp BJ, Davis JA, Torres F, Wasserman K: A test to etermineparameters of aerobic function during exercise. J Appl Physiol1981, 50:217-21.
  19. Whipp BJ, Ward SA, Lamarra N, Davis JA, Wasserman K: Parametersof entilatory nd gas exchange dynamics during exercise.J Appl Physiol 1982, 52:1506-13.
  20. American Thoracic Society/American College of Chest Physicians:ATS/ACCP Statement on ardiopulmonary Exercise Testing.Am J Respir Crit Care Med 2003, 167:1451-1452.
  21. Arena R, Myers J, Aslam S, Varughese EB, Peberdy MA: Technicalconsiderations elated o the minute ventilation/carbondioxide output slope in patients with heart failure. Chest 2003,124:720-727.
  22. . Bard RL, Gillespie BW, Clarke NS, Egan TG, Nicklas JM: eterminingthe best ventilatory efficiency measure to predict mortalityin patients with heart failure. J Heart Lung Transplant 2006,25:589-595.
  23. . Wensel R, Opitz CF, nker D, Winkler J, H─é┬Âffken G, Kleber FX,Sharma R, Hummel M, Hetzer R, Ewert R: Assessment of survivalin patients with primary pulmonary hypertension: importanceof ardiopulmonary exercise testing. Circulation 2002,106:319-24.