Abstract

Background: The ATAK complex is a rare yet clinically significant overlap of allergic and cardiac pathology. It represents a clinical continuum involving Adrenaline, Takotsubo, Anaphylaxis, and Kounis syndrome, resulting in coronary vasomotor dysfunction and transient myocardial impairment. Such presentations often resemble acute coronary syndrome (ACS), creating a diagnostic challenge in an emergency setting. Case Presentation: We present the case of a 71-year-old male with hypertension, chronic kidney disease, and a permanent pacemaker who developed acute chest tightness, dyspnea, diaphoresis and generalised urticaria immediately following intravenous meropenem administration. Initial evaluation suggested ACS and 2D-echocardiography demonstrated an acute reduction in left ventricular systolic function; however, coronary angiography revealed non-obstructive coronary arteries. Serial echocardiography demonstrated partial recovery of left ventricular systolic function. The combination of an allergic trigger, systemic hypersensitivity, and reversible myocardial dysfunction led to the diagnosis of ATAK complex. Conclusion: This case highlights the importance of considering allergic myocardial involvement in patients presenting with ACS-like features following drug exposure. Recognition of ATAK complex is essential when hypersensitivity reactions coexist with reversible cardiac dysfunction, as it prompts a broader diagnostic approach and helps avoid misclassification as obstructive coronary artery disease, ensuring timely and appropriate management.

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