Type I Kounis Syndrome Triggered by Iodinated Contrast During Coronary Angiography: A Case Report

Kounis syndrome is a rare and underrecognized condition in which acute coronary events occur alongside hypersensitivity reactions, often triggered by allergens such as contrast media. We report the case of a 79-year-old man with hypertension and no known allergies who developed type I Kounis syndrome during a repeat coronary angiography. After administration of iodinated contrast, the patient experienced a generalized erythematous rash, bronchospasm, and subsequent chest pain with hypotension and complete atrioventricular block. Electrocardiogram revealed ST-segment elevation in the inferior leads, and angiography showed diffuse severe spasm of the right coronary artery, with no signs of restenosis or thrombosis. The episode was partially relieved with intracoronary nitroglycerin and verapamil, followed by continuous nitrate infusion. No elevation in cardiac biomarkers was detected. He was successfully treated with corticosteroids, antihistamines, vasodilators, and discharged without recurrence. The absence of myocardial necrosis and the presence of reversible vasospasm confirmed a diagnosis of type I Kounis syndrome. This case highlights the importance of early recognition and dual management of allergic and cardiac components in similar presentations. Physicians should maintain high suspicion for Kounis syndrome in patients developing acute coronary symptoms after exposure to potential allergens, even in the absence of prior allergic or vasospastic history.