title: Influence of the exercise protocol on peak VO2 in patients after heart transplantation.
abstract: BACKGROUND
  The protocol and the duration of an exercise test have considerable influence on peak oxygen consumption (VO2). On a bicycle ergometer, the use of a ramp protocol with a target exercise duration of 8 to 12 minutes is recommended to reliably measure maximal oxygen uptake. Because of cardiac denervation, heart transplant recipients have a delayed heart rate adaptation to exercise, and oxygen uptake kinetics are altered.
  
  
  METHODS
  We investigated whether the rate of workload increase during exercise testing would influence peak VO2 after heart transplantation. Two symptom-limited exercise tests, applying a ramp and a 3-minute step protocol were effectuated on a bicycle ergometer.
  
  
  RESULTS
  Seventeen patients (14 men, 3 women), mean age 58.4 +/- 12.7 years, at 64.5 +/- 26.7 months post-transplant participated in the study. No statistically significant differences between the 2 protocols were found regarding total exercise duration until exhaustion (8:42 +/- 2:09 vs 8:48 +/- 2:27 minutes, p = 0.705), maximal workload reached (117.9 +/- 42.6 vs 106.4 +/- 40.5 W; p = 0.055), peak heart rate (135.8 +/- 11.6 vs 131.2 +/- 14.8 beats/min.; p = 0.061), and peak VO2 (20.9 +/- 5.2 vs 20.5 +/- 5.9 ml/kg/min; p = 0.538).
  
  
  CONCLUSIONS
  Peak VO2 seems insensitive to a stepwise or ramping exercise protocol in heart transplant patients when the workload increments are chosen in a way that a total exercise time of 8 to 12 minutes is achieved. Both protocols can therefore be applied to evaluate peak VO2.
authors.affiliation: Cardiovascular Prevention & Rehabilitation, Swiss Cardiovascular Center Bern, University Hospital (Inselspital), Bern, Switzerland. jean-paul.schmid@insel.ch
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Schmid
authors.forename: Raymond
authors.initials: R
authors.lastname: Gaillet
authors.forename: Markus
authors.initials: M
authors.lastname: Noveanu
authors.forename: Paul
authors.initials: P
authors.lastname: Mohacsi
authors.forename: Hugo
authors.initials: H
authors.lastname: Saner
authors.forename: Roger
authors.initials: R
authors.lastname: Hullin
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000368:Aged; D002985:Clinical Protocols; D015444:Exercise / Q000502:physiology; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D016027:Heart Transplantation; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011184:Postoperative Period; D012119:Respiration; D016526:Workload
chemical_list: D007773:Lactates