Abstract
Background: The prognosis of patients with a functional single ventricle has improved, with better cardiopulmonary fitness, health-related quality of life and survival. Conventional echocardiography remains the first-line technique in single ventricle follow-up. Three-dimensional (3D) echocardiography has shown recent value in congenital cardiology, but its ability to predict functional status in patients with a single ventricle remains unknown.Aim: To evaluate, in patients with a single ventricle, the association between 3D echocardiography variables and functional status determined by cardiopulmonary fitness.Methods: Children and adults with a functional single ventricle were prospectively enrolled in this multicentre study. Cardiopulmonary fitness was assessed by cardiopulmonary exercise test, 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. Health-related quality of life was assessed using the SF-36 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), two-dimensional echocardiography ejection fraction (r = 0.55, P < 0.01) and health-related quality of life 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.Conclusions Single ventricle ejection fraction and volumes measured by 3D echocardiography correlated with cardiopulmonary fitness, as determined by two main prognostic cardiopulmonary exercise test variables: VO2max and VE/VCO2 slope. Despite good reproducibility, 3D echocardiography feasibility remained limited. 3D echocardiography may be of value in single ventricle follow-up, provided that the technique and analysis software are improved