The Global Burden and Diagnostic Challenges of Undiagnosed Congenital Heart Disease in Resource-Limited Settings: A Comprehensive Systematic Review From 2000 to 2025 of Diagnostic Gaps and Solutions

Background : Congenital Heart Disease (CHD) represents a significant global health challenge, with approximately 90% of cases occurring in low-and middle-income countries (LMICs). Undiagnosed CHD leads to substantial morbidity and mortality, particularly in resource-limited settings where diagnostic capabilities are often inadequate. This comprehensive review aims to synthesize current evidence on the global burden and diagnostic challenges of undiagnosed CHD. Methods : A systematic literature search was conducted across PubMed, Scopus, and Google Scholar databases from 2000 to 2025. Studies were selected based on predefined inclusion criteria focusing on undiagnosed CHD prevalence, diagnostic challenges, and outcomes in resource-limited settings. Results : The analysis reveals significant disparities in CHD diagnosis and management between high-income countries and LMICs. Diagnostic delays range from 4 to 98 months depending on CHD type, with critical cases often presenting with severe complications. Major barriers include infrastructural deficiencies, shortage of specialized healthcare professionals, socioeconomic constraints, and limited awareness. Conclusion : Undiagnosed CHD remains a preventable global health crisis requiring multi-sectoral intervention. Implementation of simplified screening protocols, task-shifting models, and innovative telemedicine solutions could significantly reduce diagnostic delays and improve outcomes in resource-limited settings.