Myocardial bridging resulting in an atypical acute coronary syndrome in a young athlete: a case report.

Background: Myocardial bridging (MB) is considered a frequent and benign condition. However, some patients may experience symptoms. The recent ESC guidelines on sports participation provide guidance on the management of these symptomatic patients with MB but do not provide guidance in the presence of another cardiac pathology.

Case Summary: A 14-year-old-male was admitted for ongoing chest pain and palpitations. He practiced rowing at a competitive level and had an episode of exercise-induced paroxysmal atrial fibrillation (AF) a month ago. A 12-lead electrocardiogram and biomarkers orientated toward an acute coronary syndrome. Transthoracic echocardiography was normal. Cardiac magnetic resonance imaging ruled out the hypothesis of myocarditis and showed no ischemic scar. A coronary computed tomography scan showed a significant MB of the left anterior descending coronary artery. We introduced a beta-blocker and monitored the absence of inducible ischaemia with an exercise echocardiography. Our conclusion was a myocardial infarction with non-obstructive coronary arteries due to MB and adrenergic AF. Return to rowing practice including competitions was allowed under beta-blocker therapy. The 6-year follow-up showed no recurrence of AF under treatment. The patient kept on training and competing, though at a lower level.

Discussion: This atypical case demonstrates that the so-called benign MB may become malignant, in particular in conjunction with rapid non-physiologic heart rate, and that dealing with this abnormality in athletes remains difficult despite the latest guidelines. Safe return-to-play and competition remain, however, possible under medical therapy if the patient is asymptomatic and has no inducible ischaemia.