Abstract 10046: Type I Kounis Syndrome Induced by Echocardiography Contrast Agent Sulfur Hexafluoride

Abstract

Background: Acute coronary syndrome (ACS) and anaphylaxis are both medical emergencies that require prompt intervention. ACS occurring in the setting of hypersensitivity reaction, presumably secondary to inflammatory mediator release, is called Kounis Syndrome (KS). There are three subtypes of KS: Type I (clean coronary arteries), type II (pre-existing CAD), and type III (in-stent restenosis). Allergens such as medications, insect bites, foods, and contrast media have been found to result in KS. However, to our knowledge, there is only one reported case of KS induced by sulfur hexafluoride (echocardiography enhancing agent), which was categorized as KS type III. Here, we report a case of allergic reaction to this agent causing KS type I. Case Presentation: A 74-year-old woman with a history of anaphylaxis (to penicillin and cephalosporins), provoked pulmonary embolism (PE), hypertension, and hypothyroidism presented with dyspnea and was found to have bilateral subacute PE on CTA chest. She was started on a heparin drip and subsequently underwent echocardiography which showed normal RV size, systolic function, and LVEF with no wall motion abnormalities. However, shortly after receiving the sulfur hexafluoride agent, the patient was noted to be somnolent, hypotensive, and diaphoretic. Allergic reaction to the contrast was suspected and she received methylprednisolone, diphenhydramine, and famotidine. STAT EKG revealed ST elevation in inferior leads and the patient subsequently underwent cardiac catheterization which showed no evidence of significant obstructive disease. The patient remained hemodynamically stable throughout the remainder of her admission and was transitioned from heparin drip to apixaban prior to discharge. Discussion: In conclusion, allergic reactions could lead to an acute coronary syndrome with non-obstructive coronaries. As a result, it is crucial to consider KS as a differential. Figure 1 - ST elevations in the inferior leads