A 4-year-old child is referred to the pediatric echocardiogr…

A 4-year-old child is referred to the pediatric echocardiography laboratory for routine serial surveillance six weeks after completing initial treatment for Kawasaki disease. During the evaluation, the sonographer meticulously images the main, left, and right coronary artery pathways. Which of the following echocardiographic findings represents the complication of greatest clinical concern for this patient?