Transient Myocardial Ischemia and Coronary Vasospasm Precipitated by Non-Ionic Iodinated Contrast Media: A Case Report of Type I Kounis Syndrome

Abstract

Background: Intravenous iodinated contrast media can trigger life-threatening hypersensitivity reactions and acute coronary events through mast cell degranulation, termed Kounis syndrome. Type I Kounis syndrome entails coronary artery vasospasm in patients without pre-existing coronary artery disease.

Objective: To describe the clinical course, recovery trajectories, and management of Type I Kounis syndrome after non-ionic contrast media in an atopic patient.

Methods: A 41-year-old atopic woman developed severe dyspnea, diffuse bronchospasm, unmeasurable blood pressure, and hypoxemia (SpO2 88%) within minutes of intravenous iopromide 300 (20 mL) during cholangiography. She was followed at four milestones (T0, acute collapse; T1, 1 h after epinephrine; T2, 24 h; T3, 72 h) with serial 12-lead electrocardiography, arterial blood gas, point-of-care cardiopulmonary ultrasound, and transthoracic echocardiography. Values are reported descriptively.

Results: At T0 the electrocardiogram showed sinus tachycardia (122 beats/min), diffuse T-wave inversion in V1–V5, and QTc 556 ms; lactate was 5.99 mmol/L and base deficit -6.0 mmol/L. Intramuscular epinephrine (0.5 mg, 1:1,000) with crystalloid fluid was followed by hemodynamic stabilization (mean arterial pressure 26.7 to 84.0 mmHg, +214.6%) and normalization of repolarization (QTc 418 ms, -24.8%). High-sensitivity troponin T stayed below the 99th percentile (<14.0 ng/L). Echocardiography showed ejection fraction 56%, no regional wall motion abnormality, and TAPSE 2.4 cm. The Naranjo score was 8/10, a probable adverse drug reaction.

Conclusions: In this atopic patient, non-ionic contrast media were followed by transient repolarization abnormalities in keeping with Type I Kounis syndrome. Prompt intramuscular epinephrine was followed by recovery without evidence of worsening ischemia.