OBJECTIVE To examine cardiopulmonary performance in 52 adult patients with a Fontan circulation.

DESIGN Retrospective cohort study. Values of maximum oxygen uptake (Vo ₂max), maximum heart rate (HRmax), forced vital capacity (FVC), and forced expiratory volume in one second (FEV₁) were compared with predictive values for different age groups. Patients were further subdivided into those with a pulmonary artery connection (RA–PA) or right atrium to right ventricle conduit (RA–RV).

RESULTS At late follow up (median 10 years, range 1 to 26 years), patients with Fontan circulation had greatly diminished Vo ₂max, HRmax, FVC, and FEV₁ compared with predicted values. Early age at surgery had a positive impact on aerobic capacity. The FEV₁:FVC ratio indicated restrictive lung function. No differences were found with respect to any variable between patients with RA–PA connections and those with RA–RV connections.

CONCLUSIONS Patients with a Fontan circulation have greatly diminished values of aerobic capacity and a restrictive pattern of lung function. Patients with an early surgical procedure obtained higher values of Vo ₂max. The theoretical benefits of including the right ventricle in a Fontan circulation were not apparent.