Effects of an enhanced heart rate reserve on aerobic performance in patients with a heart transplant.
OBJECTIVE
The aim of this study was to investigate whether a high-intensity warm-up at the start of a graded, symptom-limited exercise test would enhance heart rate reserve and thus improve the aerobic performance of orthotopic heart transplant patients.


METHODS
Adrenal and cardiorespiratory responses were compared in 10 orthotopic heart transplant patients who performed two graded, symptom-limited exercise tests on an ergocycle.


RESULTS
At the start of the graded, symptom-limited exercise test, high intensity increased the norepinephrine level more than usual intensity between rest and the third minute of exercise. This higher norepinephrine level was followed by a higher heart rate response from the fourth minute of exercise. Heart rate reserve was enhanced during high-intensity exercise, without any significant change in peak oxygen uptake.


CONCLUSIONS
This specific warm-up enhanced heart rate reserve during a graded, symptom-limited exercise test on an ergocycle. Mechanisms more important than limited heart rate reserve are involved in the limitation of exercise tolerance in orthotopic heart transplant patients.
Ville
Nathalie S
NS
Laboratoire de Physiologie et de Biomécanique de l'Exercice Musculaire, Rennes, France.
Varray
Alain
A
Mercier
Béatrice
B
Hayot
Maurice
M
Albat
Bernard
B
Chamari
Karim
K
Préfaut
Christian
C
Mercier
Jacques
J
D000316:Adrenergic alpha-Agonists / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D016027:Heart Transplantation / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D013647:Task Performance and Analysis; D016896:Treatment Outcome
D000316:Adrenergic alpha-Agonists; D009638:Norepinephrine