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.
KeywordsCardiac rehabilitation Exercise therapy Exercise testing Fontan circulation Congenital heart disease
Compliance with Ethical Standards
Conflict of interest
Samuel Wittekind, Wayne Mays, Yvette Gerdes, Sandra Knecht, John Hambrook, William Border, and John Lynn Jefferies declare that they have no conflicts of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
- 1.Paridon SM, Mitchell PD, Colan SD, Williams RV, Blaufox A, Li JS, Margossian R, Mital S, Russell J, Rhodes J (2008) A cross-sectional study of exercise performance during the first 2 decades of life after the Fontan operation. J Am Coll Cardiol 52(2):99–107. https://doi.org/10.1016/j.jacc.2008.02.081 CrossRefPubMedGoogle Scholar
- 4.Rhodes J, Curran TJ, Camil L, Rabideau N, Fulton DR, Gauthier NS, Gauvreau K, Jenkins KJ (2005) Impact of cardiac rehabilitation on the exercise function of children with serious congenital heart disease. Pediatrics 116(6):1339–1345. https://doi.org/10.1542/peds.2004-2697 CrossRefPubMedGoogle Scholar
- 7.Wasserman K (2005) Principles of exercise testing and interpretation: including pathophysiology and clinical applications. Lippincott Williams & Wilkins, PhiladelphiaGoogle Scholar
- 8.Dimopoulos K, Okonko DO, Diller G-P, Broberg CS, Salukhe TV, Babu-Narayan SV, Li W, Uebing A, Bayne S, Wensel R (2006) Abnormal ventilatory response to exercise in adults with congenital heart disease relates to cyanosis and predicts survival. Circulation 113(24):2796–2802CrossRefPubMedGoogle Scholar
- 11.Balady GJ, Ades PA, Comoss P, Limacher M, Pina IL, Southard D, Williams MA, Bazzarre T (2000) Core components of cardiac rehabilitation/secondary prevention programs: a statement for healthcare professionals from the American Heart Association and the American Association of Cardiovascular and Pulmonary Rehabilitation Writing Group. Circulation 102(9):1069–1073CrossRefPubMedGoogle Scholar
- 12.Cardiovascular AAo & Pulmonary Rehabilitation (2013) Guidelines for cardia rehabilitation and secondary prevention programs(with web resource). Human Kinetics, ChampaignGoogle Scholar
- 19.Taylor K, La Rotta G, McCrindle BW, Manlhiot C, Redington A, Holtby H (2011) A comparison of cardiac output by thoracic impedance and direct fick in children with congenital heart disease undergoing diagnostic cardiac catheterization. J Cardiothorac Vasc Anesthesia 25(5):776–779CrossRefGoogle Scholar