To highlight the role of Cardiac MRI in differentiation of Kounis Syndrome and Hypersensitivity Myocarditis

Introduction: Kounis syndrome (KS) is defined as the concurrent acute coronary syndrome due to coronary vasospasm, in the setting of any type of hypersensitivity reaction. It is thought to be caused by the inflammatory mediators (histamine, chemokines, chymase, tryptase etc) released during the interaction of mast cells with macrophages, and T lymphocytes. Three variants of Kounis syndrome have been described: type I includes normal coronary arteries, type II variant includes culprit but quiescent preexisting atheromatous disease, and type III includes coronary artery stent thrombosis (1)....

Discussion: Both HM and KS are cardiac diseases accompanying hypersensitivity reactions to various causes, and generally mimicing acute coronary syndrome. The symptoms, laboratory, ECG and echocardiography findings of HM and KS are usually indistinguishable. So that it is challenging to establish a definitive diagnosis (3). CMR has become increasingly useful in the assessment of cardiac diseases, particularly with it’ s contrast enhanced (CE) sequences. Recent studies about the CMR appearances of KS showed that perfusion defects on first pass MRI, and EGE and/or LGE on...

CMR may be pivotal, in patients presenting with chest pain and hypersensitivity reaction, for making the definitive diagnosis of HS or KS.

1. Kounis NG. Coronary Hypersensitivity Disorder: The Kounis Syndrome. Clin Ther. 2013;35(5):563-71. 2. Park Y, Ahn SG, Ko A et al. Hypersensitivity myocarditis confirmed by cardiac magnetic resonance imaging and endomyocardial biopsy. Korean J Intern Med. 2014;29(2):236-40. 3. Almpanis GC, Mazarakis A, Dimopoulos DA et al. The conundrum of hypersensitivity car­diac disease: hypersensitivity myocarditis, acute hypersensitiv­ity coronary syndrome (Kounis syndrome) or both? Int J Cardiol. 2011;148(2):237–40. 4. Okur A, Kantarci M, Karaca L et al. The utility of cardiac magnetic resonance imaging in Kounis syndrome....