Influence of post-surgery time after cardiac transplantation on exercise responses.
Influence of post-surgery time after cardiac transplantation on exercise responses. Med. Sci. Sports Exerc., Vol. 28, No. 2, pp. 171-175, 1996. To test the hypothesis that exercise response changes with time after cardiac transplantation, we investigated the cardiorespiratory responses of nine orthotopic heart transplant patients (52.4 +/- 2 yr) during graded exercise tests (30 W.3 min-1) done at 1, 3, 6, 9 and 12 months post-surgery. At peak exercise, 1) oxygen uptake per kg of body weight (VO2), minute ventilation (VE) and oxygen pulse (O2 pulse) did not change significantly between 1 and 12 months postsurgery; 2) transplanted heart rate (HRt) and delta heart rate (peak exercise heart rate--resting heart rate) increased significantly over time (P < 0.01; P < 0.05) with a marked increase between 1 and 3 months (P < 0.05); and (3) a significant negative correlation existed between O2 pulse and HRt (r = -0.36, P < 0.05), whereas no correlation was found between delta heart rate and delta VO2 (peak exercise VO2- resting VO2, l.min-1). During submaximal exercise, HRt increased significantly over time (P < 0.001); VO2, VE, and O2 pulse showed no significant change; and the VO2-HRt relationship shifted toward higher values of HRt. We conclude that, in the absence of formal physical training, the exercise response of denervated transplanted heart increases in relation to post-surgery time but does not affect oxygen uptake at submaximal and peak levels of exercise.
Mercier
J
J
Service d'Exploration de la Fonction Respiratoire, Hôpital Arnaud de Villeneuve, Montpellier, France.
Ville
N
N
Wintrebert
P
P
Caillaud
C
C
Varray
A
A
Albat
B
B
Thévenet
A
A
Préfaut
C
C
D001794:Blood Pressure; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006339:Heart Rate; D016027:Heart Transplantation / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D010101:Oxygen Consumption; D011184:Postoperative Period; D011446:Prospective Studies; D013997:Time Factors