Ivemark syndrome in an adult with complete atrioventricular septal defect and a single ventricle with L-transposition of the great arteries: a case report

BACKGROUND: Ivemark syndrome is a rare heterotaxy disorder characterized by right atrial isomerism, complex congenital heart defects, and thoraco-abdominal anomalies. Because of such defects, survival beyond infancy is rare. CASE PRESENTATION: We report a case of a 31-year-old North African male with lifelong cyanosis who presented with worsening exertional dyspnea and fatigue. A segmental approach revealed heterotaxy with right atrial isomerism, a complete atrioventricular septal defect, a functional single ventricle with L-transposition of the great arteries, and severe valvular and supravalvular pulmonic stenosis. Despite these complex anomalies, the patient maintained a balanced circulation that enabled survival into adulthood. A multidisciplinary team recommended a palliative care approach, including intravenous hydration, iron supplementation, allopurinol, and preventive measures for infective endocarditis. The patient remains under regular noninvasive follow-up, with a stable condition. CONCLUSION: This case highlights the rare adult presentation of Ivemark syndrome. Long-term survival is exceptionally rare and depends on balanced hemodynamics, comprehensive evaluation, and individualized multidisciplinary care.