Reabilitação percutânea dos condutos extra cardíacos no PO tardio de Fontan. Para que esperar por complicações? / Percutaneous rehabilitation of extracardiac conduits in the late postoperative period of Fontan. Why wait for complications?

INTRODUÇÃO E/OU FUNDAMENTOS: Pacientes submetidos a cirurgia de Fontan podem apresentar complicações tardias que incluem congestão venosa crônica, hepatopatia, enteropatia perdedora de proteínas, bronquite plástica entre outros. Com o crescimento somático, os condutos colocados aos 2-5 anos de idade com diâmetros entre 16-20 mm se alongam longitudinalmente causando redução progressiva do diâmetro interno. Tal fenômeno pode estar envolvido nas complicações descritas. Objetivo é relatar nossa experiência com a reabilitação percutânea tardia destes condutos. MÉTODOS: Estudo observacional de pacientes com complicações tardias de Fontan com redução significativa do diâmetro do conduto externo na angiografia em PA ou perfil. A presença de gradientes não foi considerada como parâmetro para intervenção. Stents implantados com diâmetros de 18-20 mm foram usados. O seguimento constou de reavaliação clínica e laboratorial. RESULTADOS E CONCLUSÕES: Quatro pacientes (mediana idade 18 anos) foram submetidos ao procedimento com sucesso e sem complicações. Três deles apresentavam sinais e sintomas de enteropatia perdedora de proteínas e o outro congestão venosa crônica e hepatopatia. Não foram observados gradientes de pressão no conduto. Entretanto, todos apresentavam dilatação significativa da VCI e supra-hepáticas com estase local. Os diâmetros médios dos condutos aumentaram de 12 +/- 3 para 19 +/- 2 mm. Alta hospitalar foi dada no dia seguinte. Todos apresentaram melhora dos parâmetros clínicos e laboratoriais no seguimento. CONCLUSÕES: A reabilitação percutânea dos condutos extra cardíaco usados na Cirurgia de Fontan é uma modalidade terapêutica simples, segura e eficaz no manejo de possíveis complicações tardias. Postulamos que todos os pacientes no PO tardio de Fontan devam ser submetidos a investigação da redução do lumen do conduto após o estirão da puberdade e submetidos a este tipo de tratamento antes que possíveis complicações tardias se instalem. Esta conduta profilática mais agressiva deve ser investigada em experiências futuras com maior número de pacientes.

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.

A Novel Mechanism for Improved Exercise Performance in Pediatric Fontan Patients After Cardiac Rehabilitation.

Patients with a Fontan circulation have impaired exercise capacity. Cardiac rehabilitation (CR) has shown promise in enhancing peak exercise parameters in this population, but an improvement in submaximal exercise has not been consistently demonstrated. We assessed the hypothesis that participation in CR will be associated with more efficient oxygen extraction and ventilation during submaximal exercise. In this prospective study, pediatric Fontans completed two 60 min CR sessions per week for 12 weeks. Cardiopulmonary exercise testing and stress echocardiography were performed at baseline and last CR session, and then compared with a paired sample t test. Ten pediatric Fontans completed the study. Five had tricuspid atresia and five had hypoplastic left heart syndrome. No serious adverse events occurred during CR sessions. Peak indexed oxygen consumption increased by a mean of 3.7 mL/kg/min (95% CI 1.5-5.9; p = 0.004), and peak oxygen pulse increased by a mean of 0.9 mL/beat (95% CI 0.4-1.4; p = 0.004). The peak respiratory exchange ratio did not change significantly. The significant difference in oxygen pulse became evident during submaximal exercise without a corresponding difference in echocardiographic stroke volume. Indexed oxygen consumption at ventilatory anaerobic threshold increased by a mean of 3.0 mL/kg/min (95% CI - 0.07 to 6.0; p = 0.055). The slope for the volume of expired ventilation to volume of carbon dioxide production improved by a mean of 4.5 (95% CI - 8.4 to - 0.6; p = 0.03). We observed significant improvements in both submaximal and peak exercise performance in pediatric Fontans undergoing CR with no serious adverse events. These changes appeared to be mediated, at least in part, by more efficient oxygen extraction and ventilation.

Respiratory Training Late After Fontan Intervention: Impact on Cardiorespiratory Performance.

Fontan palliation allows patients with "single ventricle" circulation to reach adulthood with an acceptable quality of life, although exercise tolerance is significantly reduced. To assess whether controlled respiratory training (CRT) increases cardiorespiratory performance. 16 Adolescent Fontan patients (age 17. 5 ± 3.8 years) were enrolled. Patients were divided into CRT group (n = 10) and control group (C group, n = 6). Maximal cardiopulmonary test (CPT) was repeated at the end of CRT in the CRT group and after an average time of 3 months in the C group. In the CRT group a CPT endurance was also performed before and after CRT. In the CRT group there was a significant improvement in cardiovascular and respiratory response to exercise after CRT. Actually, after accounting for baseline values, the CRT group had decreased breathing respiratory reserve (- 15, 95% CI -22.3 to - 8.0, p = 0.001) and increased RR peak (+ 4.8, 95% CI 0.7-8.9, p = 0.03), VE peak (+ 13.7, 95% CI 5.6-21.7, p = 0.004), VO2 of predicted (+ 8.5, 95% CI 0.1-17.0, p = 0.05), VO2 peak (+ 4.3, 95% CI 0.3 to 8.2, p = 0.04), and VO2 workslope (+ 1.7, 95% CI 0.3-3.1, p = 0.02) as compared to the control group. Moreover, exercise endurance time increased from 8.45 to 17.7 min (p = 0.01). CRT improves cardiorespiratory performance in post-Fontan patients leading to a better aerobic capacity.

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.

An Early Glenn Operation May be Associated with the Later Occurrence of Protein-Losing Enteropathy in Fontan Patients : Association of Early Glenn and Failing Fontan.

Protein-losing enteropathy (PLE) and plastic bronchitis (PB) are major causes of long-term mortality after Fontan operation. The objective of this study was to determine early clinical risk factors before the onset of PLE and PB. In a cohort study, 106 Fontan patients between 2005 and 2013 were examined. A median of 5.3 (1.5-8.5) years later, follow-up questionnaires were used to group the patients in a PLE or PB group (n = 14) and a non-PLE/PB group (n = 92). Prevalence of PLE was 9.4% (n = 10) and of PB 3.8% (n = 4). At follow-up, five patients (4.7%) died of PLE or PB. Median age at death was 6.2 years (IQR 10.5, 95% CI 5.3-23.4). We observed no significant group differences in gender distribution (p = 0.73), ventricular morphology (p = 0.87), surgical technique (p = 0.64), conduit fenestration (p = 0.34), age at Fontan operation (p = 0.54), and need for diuretics (p = 0.56). Hypoplastic left heart syndrome was more frequent in the PLE/PB group 50 vs. 22.8% (p = 0.03) OR 3.4 (95% CI 1.1-10.8). The modified Glenn procedure was performed at a median age of 4 months (IQR 4.0) in the PLE/PB group versus 8 months (IQR 8.0) in the non-PLE/PB group (p = 0.01). The early Glenn procedure and hypoplastic left heart syndrome may be associated with the development of PLE and PB.

Reduced physical exercise and health-related quality of life after Fontan palliation.

AIM: A growing number of patients with Fontan circulation are reaching adulthood, and there is increasing concern about their physical performance and quality of life. This study compared self-reported exercise and measured activity with quality of life in patients after Fontan palliation and healthy controls. METHODS: Physical exercise during an average school week was reported by 30 Fontan circulation patients aged eight to 20 years, and 25 healthy controls, followed by accelerometer recordings over seven days. All subjects and their parents answered a questionnaire on quality of life. RESULTS: Patients reported spending less time exercising each week than the controls (114 ± 66 minutes vs. 228 ± 147 minutes, p < 0.001). However, the overall measured activity and moderate-to-vigorous activity was similar for patients and controls. Patients reported a lower quality of life score than the controls (70.9 ± 9.9 vs. 85.7 ± 8.0, p < 0.001). CONCLUSION: In spite of similar measured total activity, Fontan patients reported less time engaged in regular physical exercise than healthy controls and their quality of life was lower than the controls. We speculate that promoting structured regular physical exercise could improve the quality of life of Fontan patients.

Does exercise training improve cardiopulmonary fitness and daily physical activity in children and young adults with corrected tetralogy of Fallot or Fontan circulation? A randomized controlled trial.

BACKGROUND: Many patients with congenital heart disease do not meet current public health guidelines to participate in moderate-to-vigorous physical activity for ≥60 minutes per day. They are less fit than their healthy peers. We hypothesized that exercise training would increase cardiopulmonary fitness and daily physical activity in these patients. We therefore assessed effects of an exercise training program on cardiopulmonary fitness and daily physical activity in patients with corrected tetralogy of Fallot (ToF) or Fontan circulation. METHODS: In a multicenter prospective controlled trial, patients with ToF or Fontan circulation (age 10-25 years) were randomized, 56 patients to the exercise group and 37 to the control group. The exercise group participated in a 12-week standardized aerobic exercise training program. The control group continued lifestyle as usual. Cardiopulmonary exercise testing and activity measurements were performed before and after 12 weeks. RESULTS: Peak oxygen uptake increased in the exercise group by 5.0% (1.7 ± 4.2 mL/kg per minute; P = .011) but not in the control group (0.9 ± 5.2 mL/kg per minute; P = not significant). Workload increased significantly in the exercise group compared with the control group (6.9 ± 11.8 vs 0.8 ± 13.9 W; P = .047). Subgroup analysis showed a significant increase in pre-to-post peak oxygen uptake in the exercise group of ToF patients but not in the exercise group of Fontan patients. Percentage of measured time spent in moderate-to-vigorous activity at baseline was 13.6% ± 8.6%, which did not significantly change after training. CONCLUSIONS: Aerobic exercise training improved cardiopulmonary fitness in patients with ToF but not in patients with Fontan circulation. Exercise training did not change daily physical activity.

Exercise capacity in single-ventricle patients after Fontan correlates with haemodynamic energy loss in TCPC.

OBJECTIVE: Elevated energy loss in the total cavopulmonary connection (TCPC) is hypothesised to have a detrimental effect on clinical outcomes in single-ventricle physiology, which may be magnified with exercise. This study investigates the relationship between TCPC haemodynamic energy dissipation and exercise performance in single-ventricle patients. METHODS: Thirty consecutive Fontan patients with TCPC and standard metabolic exercise testing were included. Specific anatomies and flow rates at rest and exercise were obtained from cardiac MR (CMR) and phase-encoded velocity mapping. Exercise CMR images were acquired immediately following supine lower limb exercise using a CMR-compatible cycle ergometer. Computational fluid dynamics simulations were performed to determine power loss of the TCPC anatomies using in vivo anatomies and measured flows. RESULTS: A significant negative linear correlation was observed between indexed power loss at exercise and (a) minute oxygen consumption (r=-0.60, p<0.0005) and (b) work (r=-0.62, p<0.0005) at anaerobic threshold. As cardiac output increased during exercise, indexed power loss increased in an exponential fashion (y=0.9671x(3.0263), p<0.0001). CONCLUSIONS: This is the first study to demonstrate the relationship between power loss and exercise performance with the TCPC being one of the few modifiable factors to allow for improved quality of life. These results suggest that aerobic exercise tolerance in Fontan patients may, in part, be a consequence of TCPC power loss.

Children after fontan have strength and body composition similar to healthy peers and can successfully participate in daily moderate-to-vigorous physical activity.

The objective of this study was to evaluate the active lifestyle capacity (daily physical activity, strength, flexibility, body composition) of children after the Fontan procedure; hypothesized to be lower than healthy peers. Participants (n = 64, 25 females) were 9.0 ± 1.7 years of age (range 6.0-11.7 years). Fontan completion occurred at 3.3 ± 1.4 years of age (5.7 ± 2.0 years prior). Canadian Health Measures Survey protocols assessed aerobic endurance (paced walking up/down steps), strength (handgrip), flexibility (sit and reach), body composition (body mass index), and daily moderate-to-vigorous physical activity (7-day accelerometry). Difference scores compared participant data to published norms (t tests). Linear regression evaluated age/gender/demographic factor associations. Children after Fontan had strength scores similar (mean difference 1.1 kg) to their peers were less likely to be obese (mean difference of body mass index = 1.1 ± 2.5, p = 0.001) and performed 50 min of moderate-to-vigorous activity (MVPA) per day (12 ± 17 min/day below healthy peers, p < 0.001). Estimated peak endurance (61 % of expected) and flexibility (64 % of expected) were lower than peers (p < 0.001). Almost all (60/63) participants demonstrated the capacity to perform at least 20 min of MVPA per day. Difference from norms was smaller among children younger at Fontan completion (4 ± 2 min/year) and taking antithrombotic medication (7 ± 18 and 22 ± 17 min/day for taking/not taking, respectively). Children after Fontan demonstrate the capacity for the daily physical activity associated with optimal health. They have similar strength and good body composition. We recommend that children after Fontan be counselled that they can successfully participate in healthy, active lifestyles and physically active peer play.

Aerobic exercise influences quality of life of children and youngsters with congenital heart disease: a randomized controlled trial.

PURPOSE: To evaluate effects of an exercise program on health-related quality of life (HRQoL) in children and adolescents with tetralogy of Fallot (ToF) or a Fontan circulation. METHODS: Stratified, randomized, controlled intervention study conducted in five participating centers of pediatric cardiology in The Netherlands. In total, 93 patients, aged 10-25 years, with surgical repair for tetralogy of Fallot or with a Fontan circulation for single-ventricle physiology were included. They were randomly allocated with a ratio of 2:1 to: (1) a 12-week period with an exercise program for 3 times per week or (2) to a control group. Randomization was stratified by age, gender, and cardiac diagnosis. At baseline and follow-up after 12 weeks, all participants completed Web-based age-appropriate HRQoL questionnaires. Primary analyses involved change in HRQoL during follow-up. Secondary analyses concerned influence of cardiac diagnosis and comparison with normative data. RESULTS: Forty-eight (86%) and 32 (86%) patients in the exercise-group and control-group respectively completed all questionnaires at baseline and follow-up. Compared with the control-group, children, aged 10-15 years, in the exercise-group improved significantly on self-reported cognitive functioning, p < .05, r = .30, and parent-reported social functioning, p < .05, r = .30. Youngsters aged 16-25 years did not change their HRQoL. Cardiac diagnosis had no influence on pre/post changes. Children and youngsters in this study reported comparable or better HRQoL than norm groups. CONCLUSIONS: Participation in an exercise program improved HRQoL of children with ToF or a Fontan circulation, especially in those with low baseline QoL.

Living with half a heart--experiences of young adults with single ventricle physiology: a qualitative study.

BACKGROUND AND RESEARCH OBJECTIVE: Approximately 3% of children with congenital heart disease born in Denmark have single ventricle physiology (SVP). In previous decades, these children did not survive into adulthood. However, because of new surgical techniques and improved medical care, they now have a 90% survival rate. Several studies have described the somatic status of SVP patients using clinical parameters; however, only a few studies have researched the life perspectives and coping skills in this patient group. The aim of this study was to investigate how young adults with an SVP diagnosis are coping with adulthood and the emotional experiences of daily life. SUBJECTS AND METHODS: Semistructured, qualitative interviews were held with 11 SVP respondents, selected by physical and psychological parameters identified in an earlier quantitative study. Data from the interviews were analyzed by a research group using a phenomenological methodology. RESULTS AND CONCLUSIONS: The goal for SVP patients is to gain control over their disease to live normal lives. Patients require special support from their core network to overcome physical and psychological challenges. Respondents underscored the need for friends and resource persons outside the family to help lift them out of their role as disabled cardiac patients and provide them with "normal" life experiences.

Functional health status of adolescents after the Fontan procedure -- comparison with their siblings.

BACKGROUND: Studies have suggested that patients who have undergone the Fontan procedure experience lower functional health status and diminished exercise capacity compared with other children. OBJECTIVES: To compare the functional health status of Fontan patients with and without siblings, assess whether there are any differences between Fontan patients and their siblings, and determine associated factors. METHODS: A cross-sectional, single-centre, observational study was performed on Fontan patients 10 to 20 years of age, and their sibling closest in age, followed in a tertiary pediatric hospital. Functional health status was measured by the Child Health Questionnaire Child Form and the Pediatric Quality of Life Inventory. RESULTS: A total of 68 patients and 38 siblings were enrolled. Patients with siblings scored significantly lower on numerous domains of physical functional status than those without siblings. Compared with their matched siblings, Fontan patients reported significantly lower scores in all domains of the Pediatric Quality of Life Inventory and on physical (but not psychosocial) domains of the Child Health Questionnaire Child Form. Factors associated with increased patient-sibling differences included younger patient age, female sex, intracardiac lateral tunnel Fontan connection and lower ejection fraction at the time of study enrollment. CONCLUSIONS: Adolescents with Fontan physiology reported a lower functional health status in physical domains than their siblings, but had similar status in psychosocial domains. Having a sibling was associated with lower reported functional health status, suggesting an important effect of self-perceived physical limitations over true limitations.

Protocols associated with no mortality in 100 consecutive Fontan procedures.

OBJECTIVES: Results of Fontan's procedure have improved considerably, but perioperative mortality still occurs, attributed to ventricular dysfunction, stroke, arrhythmia, thromboembolism, and multi-organ dysfunction. Our protocols of operative and intensive care unit management address these potential issues, and have been associated with zero mortality, even with many high-risk candidates. METHODS: From 1996 to 2006, all Fontan patients were managed as follows: operative strategy based on aortic and single atrial cannulation, cooling on full-flow bypass, and hypothermic circulatory arrest to create the Fontan pathway. No direct caval cannulation. Use of central venous lines was completely avoided. Fresh whole blood was used for pump prime and for volume restoration. Inotropic and vasodilator therapy was continued for at least 48 h. Aspirin was used exclusively as anti-thrombotic therapy. Postoperative pleural drainage was accomplished with small pigtail catheters. The usual Fontan pathway was by lateral atrial tunnel (84), with extra-cardiac conduit when dictated by anatomy (16). RESULTS: One hundred Fontan operations were performed with no mortality. All patients were extubated by postoperative day 1. Hospital stay was 10+/-5 days. Complications were: bleeding (1), reintubation (1), emergent fenestration closure (1), pericardial effusion (4), and seizures (1). Risk factors included Fontan connection to one lung (3), diminutive pulmonary arteries (PAs) and unifocalized major aortopulmonary collateral arteries (MAPCAs) (1), discontinuous PAs (3), right ventricle dependent coronaries (3), neonatal pulmonary venous obstruction (3), Trisomy 21 (1), preoperative pacemaker dependence (2), and heterotaxy (10). No candidate was excluded. CONCLUSIONS: While many surgeons try to avoid bypass or aortic clamping when performing Fontan operations, the strategies we have employed facilitate safe accomplishment of Fontan's operation in diverse anatomic groups with multiple risk factors, with avoidance of operative mortality in 100 consecutive cases.

Physical activity levels in children and adolescents are reduced after the Fontan procedure, independent of exercise capacity, and are associated with lower perceived general health.

OBJECTIVES: To determine physical activity levels in paediatric patients who underwent the Fontan procedure, and their relationship to functional status and exercise capacity. STUDY DESIGN: We studied 147 patients (ages 7-18 years) at a median of 8.1 years after Fontan, as part of the Pediatric Heart Network cross-sectional study of Fontan survivors. Assessment included medical history, self-reported physical activity, parent-completed Child Health Questionnaire (CHQ), cardiopulmonary exercise testing and physical activity level measured by accelerometry (MTI Actigraph). RESULTS: Measured time spent in moderate and vigorous activity was markedly below normal at all ages, particularly in females, and was not significantly related to self-reported activity levels, or to maximum Vo2, Vo2 at anaerobic threshold or maximum work rate on exercise testing. Lower measured activity levels were significantly related to lower perceived general health but not to self-esteem, physical functioning, social impact of physical limitations or overall physical or psychosocial health summary scores. Reduced exercise capacity was more strongly related than measured activity levels to lower scores in general health, self-esteem and physical functioning. CONCLUSIONS: Physical activity levels are reduced after Fontan, independent of exercise capacity, and are associated with lower perceived general health but not other aspects of functional status.

Exercise capacity and impact of exercise training in patients after a Fontan procedure: a review.

After a successful Fontan procedure, children and adolescents should improve their exercise capacity. However, several studies have shown that these children have a reduced maximal oxygen consumption compared with healthy children. The lower exercise performance in these patients was mainly explained by a reduced cardiorespiratory functional capacity. However, it has recently been reported that the lower exercise performance may also be related to altered skeletal muscle function. Moreover, exercise training had a beneficial impact on several parameters related to exercise tolerance in these patients. The main studies supporting these observations are reviewed, with a focus on the physiological adaptation and limitation of the exercise performance as well as the benefits of exercise training in patients after a Fontan procedure.

Impact of exercise training on muscle function and ergoreflex in Fontan patients: a pilot study.

BACKGROUND: Several studies have demonstrated persistent reduced exercise capacity in Fontan patients even after surgical intervention. The purpose of this study was to evaluate if the skeletal muscle function of these patients is abnormal, if it correlates with exercise tolerance and if it can be improved by exercise training. METHODS: We evaluated the functional capacity of seven patients who underwent Fontan procedure (age:16+/-5 years, mean+/-SD) and seven healthy children (19+/-7 years) paired for age, sex, height and weight. Evaluation included pulmonary evaluation, neuromuscular function and exercise tolerance. Secondly, an 8-week exercise training program was performed by five of these patients. RESULTS: The ergoreflex contribution to absolute diastolic blood pressure was higher (12.5+/-4.8 vs. 5.6+/-4.2 mmHg; p=0.04) in Fontan patients vs. healthy subjects whereas a trend was encountered regarding the ergoreflex contribution to absolute systolic blood pressure (9.0+/-7.0 vs. 0.4+/-9.0 mmHg; p=0.09). Furthermore, time to fatigue of the non-dominant forearm muscles was shorter in Fontan patients vs. healthy subjects (431+/-290 vs. 847+/-347 s; p=0.03). Following exercise training, there was a significant reduction of the ergoreflex contribution to absolute values of systolic blood pressure (9.8+/-0.9 vs. 0.3+/-2.7 mmHg; p<0.05). There was an association between muscle strength and VO2 peak in Fontan patients (upper limb: r=0.895; p<0.01; lower limb: r=0.838; p<0.05, respectively). CONCLUSIONS: Skeletal muscle function in Fontan patients is abnormal which may have an impact in the reduced exercise tolerance encountered in these patients. Exercise training may have beneficial impacts on the skeletal muscle function in this population.

Post-exercise heart rate, blood pressure and oxygen uptake dynamics in pediatric patients with Fontan circulation Comparison with patients after right ventricular outflow tract reconstruction.

BACKGROUND: Post-exercise heart rate (HR) and oxygen uptake (V O(2)) recover more slowly in patients with the Fontan circulation, but little is known about the determinants of the delayed recovery. PURPOSE: To evaluate the post-exercise cardiovascular dynamics and clinical profiles in these patients. METHODS AND RESULTS: We studied 51 Fontan patients (14+/-4 years) (atriopulmonary connection, APC = 18 and total cavopulmonary connection, TCPC = 33) and compared the results with 34 patients after right ventricular outflow tract reconstruction (RVOTR) with identical exercise capacity and arterial baroreflex sensitivity (BRS) (15+/-4 years) and with 26 controls (14+/-4 years). There were no differences in post-exercise HR or VO2 declines between the Fontan and RVOTR groups. Although the systolic blood pressure (SBP) decline was delayed in the RVOTR group (p < 0.01), its early decline in the Fontan group was rapid and equivalent to that in controls. In Fontan patients, BRS had a great impact on early HR decline (p < 0.05) and early VO2 decline was determined by peak VO2, age and cardiac index (p < 0.05-0.001). TCPC and lower BRS were the main determinants of the slower SBP decline (p < 0.05). In another study of repeated paired exercise tests before and after Fontan operation, post-exercise SBP decline became greater after the operation (p < 0.07). CONCLUSIONS: In the Fontan group, post-exercise HR and VO2 declines are markedly delayed and are determined by cardiac vagal nervous activity, exercise capacity and age, respectively. Despite identical impaired hemodynamics and exercise capacity, post-exercise SBP decline is greater in the Fontan group, especially after APC, than in the RVOTR patients.