Hearts late after Fontan operation have normal mass, normal volume, and reduced systolic function: A magnetic resonance imaging study

OBJECTIVES: The purpose of this study was to assess ventricular mass, volume, and systolic function in patients late after Fontan operation by cardiac magnetic resonance imaging. BACKGROUND: An assessment of determinants for ventricular function in post-Fontan patients was intended. METHODS: Twenty-three unselected patients (9 female, 14 male) at a median age of 19.4 years (range, 7.8 to 31.3 years), at a median time of 10.5 years (range, 4.1 to 18 years) after Fontan operation were studied. A standard 1.5-T scanner was used, and analysis was performed using dedicated software. Ten healthy volunteers (median age 26.4, range 18 to 39.3 years) served as the control group. RESULTS: Median end-systolic mass index was 72.2 g/m² (range, 43 to 138 g/m²) and 86.6 g/m² (range, 52 to 123 g/m ²) in the control group (p = NS). Median end-diastolic ventricular volume was 64 ml/m² (range, 32 to 117 ml/m²) compared with 67.7 ml/m² (range, 59 to 75 ml/m²) in the control group (p = NS). Median ejection fraction was 49.3% (range, 20% to 63%) compared with 64.8% (range, 57% to 79%) in normals (p = 0.00001). CONCLUSIONS: We conclude that long-term survivors of a Fontan operation have normal ventricular mass, normal volume, but reduced systolic ventricular function.