An adolescent male was referred to our hospital due to dyspnea persisting for over a month. He has no previous medical illness and is not taking any medications. There was no history of smoking or alcohol consumption. The electrocardiogram showed ST-segment elevation in leads V1–V6, and pathological Q waves in leads II, III, aVF, V3-V6 (Fig. 1A). Biomarker assays showed significantly elevated cardiac troponin T(166.0ng/L) and N-terminal pro-brain natriuretic peptide (16,140ng/L). The patient underwent an emergent coronary angiogram, which revealed coronary artery pulsatile ectasia in the left main and left anterior descending branch, along with occlusion of the left circumflex branch and right coronary artery, and thrombus formation at the middle-distal segment of the left anterior descending coronary artery (Fig.
