Cardiac involvement mimicking acute coronary syndrome in idiopathic hypereosinophilic syndrome

Hypereosinophilic syndrome (HES) is defined as a persistent eosinophilia lasting longer than 6 months of unknown origin and related to organ involvement. Cardiac involvement, usually leading to morbidity and mortality of HES patients, often mimics other diseases such as acute coronary syndrome. We report a 46-year-old female who came to hospital with atypical chest pains and a known history of eosinophilia. After excluding other possible causes of eosinophilia, she underwent further cardiac investigations. She had normal cardiac size on echocardiography and no thrombus or mass, with only global hypokinesia with systolic and diastolic dysfunction noted. These findings were different from other studies. This patient was then treated as HES with cardiac involvement.