Résumé
Background: prognosis of patients with a functional single ventricle (SV) has improved, with better cardiopulmonary fitness, health-related quality of life (HRQoL), and survival. Conventional echocardiography remains the first-line technique in SV follow-up. Threedimensional (3D) echocardiography has shown recent interest in congenital cardiology, but its ability to predict functional status in SV remains unknown. Aims: to evaluate, in patients with SV, the association between 3D-echocardiography parameters and functional status determined by cardiopulmonary fitness. Methods: children and adults with functional SV were prospectively enrolled in this multicentre study. Cardiopulmonary fitness was assessed by cardiopulmonary exercise test (CPET) with measures of maximum oxygen uptake (VO2max) and ventilatory efficiency (VE/VCO2 slope). 3D-echocardiography was performed with off-line reproducibility analyses using TomTec Arena™ software. HRQoL was assessed using the SF36 questionnaire. Results: a total of 33 patients were screened, and 3D-echocardiography analyses were feasible in 22 subjects (mean age 28±9 years). 3D-echocardiography ejection fraction correlated with percent-predicted VO2max (r=0.64, P<0.01), VE/VCO2 slope (r=-0.41, P=0.05), 2D-echocardiography ejection fraction (r=0.55, P<0.01), and HRQoL physical functioning dimension (r=0.56, P=0.04). 3D-echocardiography indexed end-systolic volume correlated with percent-predicted VO2max (r=-0.45, P=0.03), and VE/VCO2 slope (r=0.65, P<0.01). 3D-echocardiography reproducibility was good. Conclusion: SV ejection fraction and volumes measured by 3D-echocardiography correlated with cardiopulmonary fitness, as determined by two main prognostic CPET parameters, e.g., the VO2max and the VE/VCO2 slope. Despite a good reproducibility, the feasibility of 3D-echocardiography remained limited. 3D-echocardiography may be of interest in SV follow-up, provided the technique and analysis software are improved.