Echocardiographic imaging and anatomic characteristics of true univentricular heart manifesting as double inlet - double outlet right ventricle: Case report and literature review

Double Inlet-Double Outlet Right Ventricle (DI-DORV) is a rare and unique single-ventricular congenital heart disease with variable atrioventricular valve morphology and myocardial structure. In patients of DI-DORV the two atria are connected to the RV by two atrioventricular (AV) valves or a common set of AV valve. The right ventricle is identified by its anatomical markers (thick trabeculae, interventricular-marginal trabeculae, and Lance's muscle), and the left ventricle by the smooth endocardium surface of the basal interventricular septum. Due to different forms of the right ventricular myocardium, hypertrophy of muscle trabeculae may be mistaken for ventricular septum, which may be challenging for diagnosing DI-DORV. The patients of DI-DORV often die early due to volume overload or persistent cyanosis leading to gradual deterioration of ventricular function. Patients are often prone to recurrent chest infections since childhood, seriously affecting physical development and causing congestive heart failure at an early stage. However, the complexity and diversity of DI-DORV lesions lead to great difficulty in clinical diagnosis. The most common surgical treatment is a staged modified Fontan palliative surgery. Transthoracic echocardiography (TTE) can accurately and reliably estimate the cardiac structure and function and plays an essential role in diagnosing and managing patients with DI-DORV. Furthermore, utilising the current non-invasive imaging techniques like cardiac CT and cardiac MRI, in situations where echocardiography is unable to deliver a precise diagnosis, are essential for optimal surgical management to improve the survival rates and quality of life. Here we are presenting a case report of a deeply cyanotic 3-month-old male infant afflicted with complex congenital cardiac defect: double inlet-double outlet right ventricle (DI-DORV) associated with A-malposition of great arteries and severe pulmonary valvular stenosis.