Sleep-disordered Breathing in Eisenmenger Syndrome

Inclusion Criteria: * Eisenmenger Syndrome (definition: Pulmonary ≥ systemic vascular resistance with pulmonary-to-systemic shunt and cyanosis (periphery oxygen saturation \< 92% at rest and/or \< 87% during exercise). * Stable for ≥ 3 months (no hospitalization, no change of medication, no deterioration). Exclusion Criteria: * Down's syndrome. * Iron deficiency (definition: Ferritin \< 12 µg/l and/or transferring saturation \< 20%). * Regular phlebotomy. * Suspicion of risk of non-compliance.