Severe hypocalcaemia mimicking acute coronary syndrome

Hypocalcaemia is a common electrolyte deficiency that can be found in up to 28% of hospitalised patients. It may affect cardiac and smooth muscle tone, leading to ECG abnormalities and, in rare cases, coronary spasms and heart failure. This is a case of a pregnant woman in preterm labour who developed vasospastic angina and corrected QT interval (QTc) prolongation on ECG from severe hypocalcaemia, which likely occurred due to iatrogenic hypermagnesaemia. She had a negative diagnostic workup for acute coronary syndrome, and her chest pain and QTc prolongation ultimately resolved with intravenous electrolyte repletion. This case highlights the importance of considering hypocalcaemia on the differential of chest pain that is possibly cardiac in origin.