Heat Stroke or Acute Coronary Syndrome? A Summer Collapse With an Unexpected Cardiac Twist.

Heat stroke is a life-threatening medical emergency characterised by severe hyperthermia and central nervous system dysfunction. Cardiac manifestations, including troponin elevation and electrocardiographic abnormalities, are well recognised and may mimic acute coronary syndrome (ACS). Distinguishing heat-related myocardial injury from true ACS can therefore be challenging. We report the case of a 60-year-old man who presented after being found unresponsive in his garden during a hot summer day. His pre-hospital core temperature exceeded 42.2°C, and he had a markedly reduced level of consciousness. Following active cooling measures and supportive treatment, his neurological status improved rapidly. Initial investigations demonstrated elevated high-sensitivity troponin T levels without acute ischaemic electrocardiographic changes. Owing to his cardiovascular risk factors and unexplained collapse, he was treated for non-ST-elevation ACS. Transthoracic echocardiography subsequently demonstrated regional wall motion abnormalities, and coronary angiography revealed significant proximal left anterior descending artery disease requiring percutaneous coronary intervention. This case highlights the diagnostic challenge of differentiating heat stroke-related myocardial injury from concomitant coronary artery disease and emphasises the importance of careful cardiovascular assessment in patients presenting with heat stroke and elevated cardiac biomarkers.