Survival Beyond Expectations: A Rare Case of Adult Life in Double Inlet Left Ventricle without Fontan Completion

Abstract

Background: Double inlet left ventricle (DILV) is a rare congenital heart disease characterized by a single functioning ventricular chamber, most commonly the left ventricle, receiving inflow from both atrioventricular valves. Without complete surgical palliation—particularly the Fontan procedure—survival into adulthood is rare due to complications such as heart failure, cyanosis, and arrhythmias. Case Presentation: We present the case of a 40-year-old woman diagnosed with DILV during infancy, who survived into mid-adulthood without undergoing Fontan completion. The patient had received a first-stage palliative surgery early in life but was lost to follow-up thereafter. Despite limited healthcare access and a modest lifestyle, she lived a relatively functional life, bore a healthy child, and remained stable until a recent decline in exercise tolerance following a COVID-19 infection. Results: Echocardiography and cardiac MRI confirmed the diagnosis of DILV with a hypoplastic right ventricle, competent atrioventricular valves, normally related great arteries, and preserved left ventricular systolic function. Hemodynamics revealed a balanced Qp/Qs ratio of 1:1 and mild pulmonary hypertension. The patient was managed conservatively and discharged with regular cardiology follow-up. Conclusion: This case challenges the traditional paradigm that surgical completion with the Fontan procedure is universally necessary for long-term survival in DILV. Individualized hemodynamics and anatomical balance can permit extended survival in select patients. The report emphasizes the need for tailored management strategies and long-term monitoring in congenital heart disease.