Selective Intracoronary Injection of Nitrates Was Effective for Contrast Media-induced Type I Kounis Syndrome After Treatment with Steroids and Antihistamines

A 77-year-old man presented for computed tomography (CT) with iodinated contrast for follow-up of gastric cancer. After contrast injection, the patient experienced cardiac arrest. A post-return spontaneous circulation electrocardiogram showed ST segment elevation in the inferior leads and V1-3. Since type I Kounis syndrome (KS) was suspected, corticosteroids and antihistamines were administered intravenously. Subsequently, coronary angiography (CAG) revealed coronary spasms, and selective intracoronary injection of nitrates successfully resolved each spasm. Strategic substitution of contrast media did not induce any additional allergic reactions. The optimal timing and preferred strategies for performing CAG in patients with KS were also discussed.