Overcoming Anatomical Complexity: Atrial Flutter Ablation in the setting of Left Atrial Isomerism and surgically repaired sinus venosus defect

Left atrial isomerism (LAI) is a form of heterotaxy syndrome, defined by symmetrical left anatomy of the atria and bronchi. Typical features include presence of two morphologically left lungs, two morphologically left atrial appendages, interruption of the hepatic segment of the inferior vena cava, midline liver, polysplenia, and high incidence of congenital heart defects (1). Most frequently encountered are double right ventricular outflow tract, single atrium, atrioventricular septal defect, pulmonary valve stenosis and persistent left superior vena cava (LSCV) (2).