Introduction: Fontan operation is a palliative procedure used in patients with univentricular heart (UVH). There have been numerous modifications to the technique. The appropriate strategy for treating patients with UVH in Thailand is still a major
concern.
Objective: To describe the outcomes of patients after straightforward Fontan operation at advanced-age and evaluate their post-surgical cardiac performance.
Material and Method: A cross sectional study was performed in post-Fontan operation patients at Rajvithi Hospital between
2000 and 2009. Post-operative cardiac performance was analyzed using the echocardiogram and treadmill exercise stress
test (EST).
Results: Thirty-nine patients were enrolled in the present study. The mean age was 11.7 years and the mean age at operation was 7.4 years. The predominant systemic chamber was morphologic left ventricle. Straightforward Fontan operation was performed in 60% of cases. Mean of Fontan index, mean of McGoon ratio, and mean of Nakata index were 2.63, 2.32, and
414.15 sqmm/sqm, respectively. Mean of the PVR and PAP were 1.98 U/m2 and 11.05 mmHg. Eighteen percent of patients died
in the early post-operative period. Most of the patients died from septicemia. The mean EF was 58.43 %. Systolic dysfunction
in 17.9% of the cases was abnormal, whereas diastolic dysfunction was present in half of the cases. Thirty-nine percent had MPI abnormality. During EST, three cases developed arrhythmias and 3 cases had hypotension. Patients were categorized into 3 groups (Group 1: normal systolic and diastolic functions, Group 2: diastolic dysfunction, Group 3: impairment of both systole and diastole). Pre-operative cardiac catheterization parameters, surgical data and cardiac performance showed no statistical significance. However, there was a significant correlation between those with abnormal cardiac performance and arrhythmias or hypotension during EST (p = 0.003).
Conclusion: The selection of suitable cases and good pre-operative evaluation could decrease the morbidity and mortality in patients undergoing the Fontan procedure. This study also found a correlation between abnormal cardiac performance and transient cardiac arrhythmia during exercise. The evaluation of cardiac performance and EST remains to be performed for following-up of patients who have undergone the Fontan operation, even for the asymptomatic cases.

Keywords: Post, Fontan operation, Outcome