Asian Journal of Cardiology Research

Aims: To report an exceptional case of a previously undiagnosed single ventricle congenital heart disease presenting in the fifth decade of life, and to discuss the challenges of late diagnosis in the context of established, inoperable pulmonary hypertension.

Introduction: Single ventricle physiology represents a complex spectrum of congenital heart diseases typically diagnosed and palliated in infancy. Survival into adulthood without prior surgical intervention is exceedingly rare and poses unique diagnostic and management challenges, often complicated by irreversible pulmonary vascular disease.

Case Presentation: A 50-year-old man with no prior medical history presented to the emergency department with acute-onset dyspnea and cyanosis. He was a father of four and had been gainfully employed without functional limitation. Electrocardiography revealed atrial flutter. Echocardiography and subsequent advanced imaging diagnosed a complex single ventricle anomaly (likely a double-inlet left ventricle with transposition) with severe, fixed pulmonary hypertension. Despite medical management of acute heart failure, he was deemed ineligible for surgical palliation due to advanced pulmonary vascular disease and was discharged on guideline-directed medical therapy and anticoagulation.

Discussion: This case underscores a profound failure of the healthcare system, where a life-threatening congenital anomaly remained undetected for five decades. The patient's remarkable adaptation and compensation highlight the body's physiological reserve, but also mask a condition where timely, childhood surgical intervention (e.g., Fontan procedure) could have offered a survival pathway. The development of irreversible pulmonary hypertension is the direct consequence of delayed diagnosis, transforming a potentially palliable condition into an inoperable one. This emphasizes the critical, non-negotiable importance of neonatal and childhood cardiac screening.

Conclusion: The asymptomatic survival of an adult with unoperated single ventricle physiology is a medical curiosity that carries a sobering message. It serves as a powerful reminder that the window for successful surgical palliation in complex congenital heart disease is often narrow and defined by the status of the pulmonary vasculature. Early diagnosis is not merely beneficial—it is a prerequisite for curative or palliative surgical strategy.