Restrictive lung function defined by body plethysmography is common in children with Fontan palliation and functionally relevant

BackgroundPulmonary dysfunction is common in single ventricle (SV) patients with Fontan circulation, yet the prevalence and clinical relevance of true restrictive lung disease remain poorly characterized as most studies relied on spirometry alone. This study comprehensively assessed lung function using spirometry and body plethysmography, examined its relationship with cardiac magnetic resonance (CMR)-derived lung volumes, evaluated its impact on exercise capacity, and identified clinical correlates of restrictive physiology.MethodsIn this prospective, single-centre study, 31 children and adolescents with Fontan circulation underwent spirometry, body plethysmography, cardiopulmonary exercise testing (CPET), and CMR. Restrictive lung function was defined by reduced (