Early-onset Atrial Fibrillation in Brothers with a Huge Left Atrial Appendage

Having a relative with atrial fibrillation (AF) is one of the risk factors for AF development, especially in young patients, which is known as familial AF. Although familial AF is considered to be associated with inherited factors, its genetic and pathophysiological backgrounds have not been fully identified. We report two young brothers undergoing radiofrequency catheter ablation for AF, who had a huge left atrial appendage (LAA). In both cases, the origins of the main triggers of the AF were not the huge LAA itself, but left pulmonary veins compressed by the LAA. Since catheter ablation including pulmonary vein isolation, the sinus rhythm has been maintained in both patients.