A 22-year-old female with a history of aortic and mitral valve replacement was admitted with a 4-week history of dyspnea and chest pain. Emergency coronary angiography revealed not only external compression of the left main coronary artery due to an aortic root abscess, but also the dual left anterior descending artery arising from the left and right coronary sinus. Although aortic root abscess is a well recognized complication of aortic valve endocarditis, coronary artery compression is an unusual mode of presentation. The binary distribution of the left anterior descending artery may limit the extent of ischemic insult to the anterior wall and thus led to a more insidious clinical course.