The aim of the study was to report the clinical and echocardiographic data of patients who underwent a Fontan operation, and define the group with systolic dysfunction in the systemic ventricle observed during postoperative follow-up. The medical records of 183 patients [mean age: 10.93 ± 5.89 years (range: 2.5-45 years)] who were referred to our center and underwent a Fontan operation were retrospectively reviewed. The clinical, echocardiographic, and postoperative follow-up data of the patients were recorded. Preoperatively, 68 (37.2%) patients experienced pulmonary stenosis, while 41 (22.4%) had pulmonary atresia and 74 (40.4%) had pulmonary hypertension. The most common pathology in patients who were ineligible for biventricular repair was tricuspid atresia, seen in 51 patients (27.9%), followed by double-inlet left ventricle pathologies in 40 patients (21.9%). In total, 38 (20.7%) patients had a biventricular structure; among those with a single ventricular structure, the systemic ventricle involved was the right ventricle in 51 (27.9%) patients and the left ventricle in 94 (51.4%) patients. During follow-up, a total of 31 (16.9%) patients underwent catheterization and ventricular systolic functions were preserved in 168 (91.8%) patients. In Fifteen (8.2%) patients developed systolic dysfunction (ejection fraction < 50%). The mean age of the group developing systolic dysfunction was 15.6 ± 2.63 years (median, 13 years; range: 5-45 years). Of this group, 10 patients had a left ventricular structure of the systemic ventricle, 14 had atrial situs solitus, and 4 had moderate atrioventricular valve insufficiency. Even if the systemic ventricle is in the left ventricular structure, systolic dysfunction in the systemic ventricle develops, especially after the first 10 years, and this makes us think rudimentary ventricle function should also be carefully monitored for intra-univentricular diastolic asynchrony.

Keywords: children, fontan operation, ventricular disfunction