Appropriate heart rate during exercise in Fontan patients.

OBJECTIVE: To evaluate heart rate against workload and oxygen consumption during exercise in Fontan patients. METHOD: Fontan patients (n = 27) and healthy controls (n = 25) underwent cardiopulmonary exercise testing with linear increase of load. Heart rate and oxygen uptake were measured during tests. Heart rate recovery was recorded for 10 minutes. RESULTS: Heart rate at midpoint (140 ± 14 versus 153 ± 11, p < 0.001) and at maximal effort (171 ± 14 versus 191 ± 10 beats per minute, p < 0.001) of test was lower for patients than controls. Heart rate recovery was similar between groups. Heart rate in relation to workload was higher for patients than controls both at midpoint and maximal effort. Heart rate in relation to oxygen uptake was similar between groups throughout test. Oxygen pulse, an indirect surrogate measure of stroke volume, was reduced at maximal effort in patients compared to controls (6.6 ± 1.1 versus 7.5 ± 1.4 ml·beat-1·m-2, p < 0.05) and increased significantly less from midpoint to maximal effort for patients than controls (p < 0.05). CONCLUSIONS: Heart rate is increased in relation to workload in Fontan patients compared with controls. At higher loads, Fontan patients seem to have reduced heart rate and smaller increase in oxygen pulse, which may be explained by inability to further increase stroke volume and cardiac output. Reduced ability to increase or maintain stroke volume at higher heart rates may be an important limiting factor for maximal cardiac output, oxygen uptake, and physical performance.

Impaired lung function in children and adolescents with Fontan circulation may improve after endurance training.

OBJECTIVES: The objective of this research was to study lung function, physical capacity, and effect of endurance training in children and adolescents after Fontan palliation compared with healthy matched controls. METHODS: Fontan patients (n=30) and healthy matched control patients (n=25) performed dynamic and static spirometry, and pulmonary diffusing capacity and maximal oxygen uptake tests, before and after a 12-week endurance training programme and at follow-up after 1 year. RESULTS: Fontan patients had a restrictive lung pattern, reduced pulmonary diffusing capacity (4.27±1.16 versus 6.61±1.88 mmol/kPa/minute, p<0.001), and a reduced maximal oxygen uptake (35.0±5.1 versus 43.7±8.4 ml/minute/kg, p<0.001) compared with controls. Patients had air trapping with a higher portion of residual volume of total lung capacity compared with controls (26±6 versus 22±5%, p<0.05). Vital capacity increased for patients, from 2.80±0.97 to 2.91±0.95 L, p<0.05, but not for controls after endurance training. The difference in diffusing capacity between patients and controls appeared to be greater with increasing age. CONCLUSIONS: Fontan patients have a restrictive lung pattern, reduced pulmonary diffusing capacity, and reduced maximal oxygen uptake compared with healthy controls. Endurance training may improve vital capacity in Fontan patients. The normal increase in pulmonary diffusing capacity with age and growth was reduced in Fontan patients, which is concerning. Apart from general health effects, exercise may improve lung function in young Fontan patients and should be encouraged.

Can endurance training improve physical capacity and quality of life in young Fontan patients?

OBJECTIVE: Children after Fontan palliation have reduced exercise capacity and quality of life. Our aim was to study whether endurance training could improve physical capacity and quality of life in Fontan patients. METHODS: Fontan patients (n=30) and healthy age- and gender-matched control subjects (n=25) performed a 6-minute walk test at submaximal capacity and a maximal cycle ergometer test. Quality of life was assessed with Pediatric Quality of Life Inventory Version 4.0 questionnaires for children and parents. All tests were repeated after a 12-week endurance training programme and after 1 year. RESULTS: Patients had decreased submaximal and maximal exercise capacity (maximal oxygen uptake 35.0±5.1 ml/minute per·kg versus 43.7±8.4 ml/minute·per·kg, p<0.001) and reported a lower quality of life score (70.9±9.9 versus 85.7±8.0, p<0.001) than controls. After training, patients improved their submaximal exercise capacity in a 6-minute walk test (from 590.7±65.5 m to 611.8±70.9 m, p<0.05) and reported a higher quality of life (p<0.01), but did not improve maximal exercise capacity. At follow-up, submaximal exercise capacity had increased further and improved quality of life was sustained. The controls improved their maximal exercise capacity (p<0.05), but not submaximal exercise capacity or quality of life after training. At follow-up, improvement of maximal exercise capacity was sustained. CONCLUSIONS: We believe that an individualised endurance training programme for Fontan patients improves submaximal exercise capacity and quality of life in Fontan patients and the effect on quality of life appears to be long-lasting.