Cardiol Young 2009; 19: 340–345 r Cambridge University Press ISSN 1047-9511 doi:10.1017/S1047951109990424 First published online 15 June 2009 Original Article Exercise capacity reflects ventricular function in patients having the Fontan circulation Katrin Klimes, 1 Stanislav Ovroutski, 1 Hashim Abdul-Khaliq, 2 Peter Ewert, 1 Vladimir Alexi-Meskishvili, 3 Titus Kuehne, 1 Matthias Gutberlet, 4 Felix Berger 1 Departments of 1 Congenital Heart Defects/Pediatric Cardiology, Deutsches Herzzentrum Berlin, 2 Pediatric Cardiology, Universita¨t des Saarlandes, 3 Thoracic and Cardiovascular Surgery, Deutsches Herzzentrum Berlin, and 4 Diagnostic and Interventional Radiology, Herzzentrum Leipzig, Germany Abstract Background: In this study we sought to determine, first, whether maximal exercise capacity reflects ventricular function, and second, whether the age of the patient, and the age of completion of the Fontan circulation, influence ventricular function and exercise performance. Methods and Results: Cardiac magnetic resonance imaging and cardiopulmonary exercise testing were performed in 29 patients at a median time of 6.9 years after completion of the Fontan circulation. We divided the patients into 2 groups, the first 19 having their operation below the age of 18 years, and the second group, of 10 patients, having completion of the Fontan circulation when they were older than 18 years. Parameters for ventricular function and exercise were compared for both groups with controls. Compared to controls, the younger patients had normal end-diastolic ventricular volumes, but significantly impaired ventricular function, lower maximal work load and consumption of oxygen. The older patients had greater end-diastolic ventricular volumes, and significantly poorer ventricular function than both the younger patients and the controls. Maximal work load and consumption of oxygen were significantly lower in the older patients than in the younger ones and the controls. Conclusion: Patients with the Fontan circulation have an impaired systolic ventricular function, which correlates with maximal exercise capacity and uptake of oxygen. Those having completion of the Fontan circulation when younger than 18 years had significantly better ventricular function and exercise performance than those who had completion of the Fontan circulation at an older age. An early creation of the Fontan circulation may preserve cardiac function and exercise capacity. Keywords: Functionally univentricular heart; cavopulmonary connection; congenital heart disease T HE FONTAN OPERATION WAS INTRODUCED IN 1971 as a palliative procedure for patients with tricuspid atresia. The Fontan circulation is nowadays created in patients with various com- plex cardiac malformations, most frequently for those having functionally univentricular hearts. 1,2 In the current era, such children usually have completion of their Fontan circulation between the ages of 2 and 4 years. After beginning this procedure at our institution, however, many patients did not undergo completion of the Fontan circulation until adulthood. Advances in creating a haemodynamically improved pathway for the circulation, and better selection of patients, have led to extended survival. The patterns in flow in the Fontan circuit have been examined in various studies. 3–7 Despite a satisfactory functional state in most patients, many studies have shown an impairment of ventricular function and exercise performance. 8–15 So far, long-term follow-up data in these patients is sparse, especially in respect to age of the patients, and their age at conversion to the Fontan circuit. In this Correspondence to: Katrin Klimes, MD, Department of Congenital Heart Defects/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Tel: 149-30-4593-2800; Fax: 149-30-4593- 2900; E-mail: klimes@dhzb.de Accepted for publication 4 May 2009