Cardiac Arrest During Exertion as a Presentation of Undiagnosed Kawasaki Disease: A Case Report

<b>Background:</b> Kawasaki Disease (KD) is self-limited vasculitis, the main consequence of which may be involvement of the coronary arteries, especially in patients without treatment. It is estimated that coronary artery aneurysms occur in 15% to 25% of untreated children. Patients with coronary aneurysms may remain asymptomatic for years. The first symptom may be life-threatening sudden cardiac arrest or myocardial ischaemia. <b>Methods:</b> We report a case of a 17-year-old boy with an insignificant past medical history who presented with sudden cardiac arrest. <b>Results:</b> During diagnostics, channelopathies, structural heart defects, drug abuse, and myocardial infarction were excluded. The patient underwent coronary angiography, confirmed by CT angiogram of the coronary vessels, which revealed most likely ruptured, clotted, well-calcified aneurysm of the left anterior descending artery (LAD) with collateral circulation, probably a consequence of untreated Kawasaki disease in early childhood. <b>Conclusions:</b> Complications of KD should be considered in the differential diagnosis of sudden cardiac arrest, especially in a young person.