Adrenaline, Takotsubo Cardiomyopathy, Anaphylaxis, and Kounis Syndrome (ATAK) Complex: Clinical Phenotypes, Differential Diagnosis, and Management.

backgroundAnaphylaxis is a severe hypersensitivity reaction that may involve the heart through overlapping inflammatory, vascular, and catecholaminergic mechanisms. The ATAK (adrenaline, Takotsubo cardiomyopathy, anaphylaxis, Kounis syndrome) complex describes a clinical continuum in which hypersensitivity-mediated inflammation and endogenous or exogenous catecholamines promote endothelial injury, coronary vasomotor and microvascular dysfunction, and myocardial damage. CASE SUMMARY: A 79-year-old man with urinary sepsis developed an antibiotic-related hypersensitivity reaction followed by acute pulmonary edema with severe biventricular dysfunction. Multimodality cardiovascular imaging and early endomyocardial biopsy assessment supported a diagnosis of Kounis syndrome with superimposed Takotsubo cardiomyopathy, consistent with the ATAK complex. Recovery followed administration of high-dose corticosteroids and intensive supportive care. TAKE-HOME MESSAGES: Increasing evidence suggests an association between anaphylaxis and cardiac involvement, although mechanisms remain incompletely understood. Catecholamine excess may exacerbate myocardial injury and promote ATAK overlap phenotypes. Multimodality imaging and early endomyocardial biopsy can refine diagnosis and guide targeted management.