[Functional non-invasive cardio-respiratory evaluation a month and a year after orthotopic heart transplantation].

Cardio-respiratory stress tests of 14 patients, performed one month and one year after orthotopic heart transplant, are compared in order to demonstrate the functional and metabolic improvements of their adaptation to stress. At maximal stress, we note a 33 p. cent increase of the oxygen consumption (p 0.001), an 11 p. cent increase of the heart rate (p 0.025) and an 18 p. cent increase of the systolic arterial pressure (p 0.005). Respiratory quotients and respiratory equivalent for oxygen are significantly lower (p 0.008) while there was no significant variation of ventilation/minute, respiratory rate, and the normal capacity. At the sub-maximal level, the only significant differences observed are the decrease of the respiratory quotient (p 0.01), the ventilation/minute (p 0.025), the respiratory equivalent for oxygen (p 0.005) and the respiratory rate (p 0.03). The improvement of the physical condition observed in heart transplants seems related to a better peripheral adaptation to stress (lower respiratory quotients, reflection of the decreased demand on anaerobic metabolism) permitting a lesser demand on the ventilatory response to stress.