When subarachnoid hemorrhage mimics acute coronary syndrome in out-of-hospital cardiac arrest: a diagnostic challenge

Out-of-hospital cardiac arrest (OHCA) is most often due to acute coronary syndrome (ACS), but less frequent causes like subarachnoid hemorrhage (SAH) may mimic cardiac disease through ECG changes and biomarker elevation, risking misdiagnosis and inappropriate interventions. The aim of this case was to present a case of a patient who experienced OHCA due to subarachnoid hemorrhage mimicking ACS leading to catastrophic results. A 42-year-old woman with no cardiovascular risk factors suffered sudden cardiac arrest during exercise. Initial ECG and troponin levels suggested SCA, but coronary angiography was normal. Subsequent head CT revealed a massive subarachnoid hemorrhage. Despite supportive care, the patient died on day 5 from cerebral edema. SAH can cause cardiac arrest with ECG changes mimicking ACS, highlighting the importance of cranial CT in comatose post–cardiac arrest patients.