Article

Heart transplant recipients have lower exercise capacity and impaired
cardiac function compared with the normal population.
High-intensity interval
training (HIIT) improves exercise capacity and cardiac function in patients with
heart failure and hypertension, but the effect on cardiac function in stable
heart transplant recipients is not known. Thus, we investigated whether HIIT
improved cardiac function and exercise capacity in stable heart transplant
recipients by use of comprehensive rest- and exercise-echocardiography and
cardiopulmonary exercise testing. METHODS: Fifty-two clinically stable
heart transplant recipients were randomised either to HIIT (4 x 4 minutes at
85-95% of peak heart rate three times per week for eight weeks) or to control.
Three such eight-week periods were distributed throughout one year.
Echocardiography (rest and submaximal exercise) and cardiopulmonary exercise
testing were performed at baseline and follow-up. RESULTS: One year of HIIT
increased VO 2peak from 27.7 +/- 5.5 at baseline to 30.9 +/- 5.0 ml/kg/min at
follow-up, while the control group remained unchanged (28.5 +/- 7.0 vs. 28.0 +/-
6.7 ml/kg per min, p < 0.001 for difference between the groups). Systolic and
diastolic left ventricular functions at rest and during exercise were generally unchanged by HIIT. CONCLUSIONS: Whereas HIIT is feasible in heart transplant
recipients and effectively improves exercise capacity, it does not alter cardiac
systolic and diastolic function significantly. Thus, the observed augmentation in
exercise capacity is best explained by extra-cardiac adaptive mechanisms.

Langue : ANGLAIS