L-looped Transposition of the Great Arteries in a Patient with Marfanoid Habitus: First Reported Case in Literature.

L-looped transposition of great arteries (L-TGA) is an extremely rare heart condition. It is associated with physiologically corrected transposition of great vessels, leading to the normal return of deoxygenated systemic venous blood to the heart and transport of oxygenated pulmonary venous blood to the main systemic circulation. Anatomic discordancy and anomalous coronary artery distribution predispose the right ventricle to excessive workload and eventual heart failure. This mandates anatomic correction or proper medical management of heart failure. Herein, we present a case of a 14-year-old girl who presented to our cardiology consults with a false impression of pre-made clinical diagnosis of tetralogy of Fallot. She had increasing dyspnea and cyanosis on presentation. Striking marfanoid habitus and unusual echocardiographic findings of tripartite geometry of heart with parallel and discordant positioning of atria, ventricles, and great arteries led us to cardiac computed tomography which confirmed the diagnosis of L-TGA. Our patient also had associated patent ductus arteriosus, dextrocardia, ventricular septal defect (VSD), and pulmonary atresia. Due to the complex nature of heart disease and unavailability of resources, she was treated with a comprehensive heart failure protocol and followed up clinically and radiologically at regular intervals and showed massive improvement. This is the first-ever documented case of L-TGA with complex shunting and marfanoid habitus.