Hypercalcemia-Induced ST-Segment Elevation Mimicking Acute Myocardial Injury: A Case Report and Review of the Literature.

ST-segment elevation in absence of acute coronary syndrome can be seen in multiple conditions, including acute pericarditis and coronary vasospasm, but it is rarely seen with severe hypercalcemia. The authors present a case of an 81-year-old female with a history of stage 4 squamous cell cancer of the lung, who presented to the emergency room with profound fatigue, weakness, anorexia, and drowsiness two weeks after her first chemotherapy cycle. Additionally, she had complaints of right-sided chest pain associated with worsening shortness of breath, as well as right arm numbness. An EKG obtained on arrival to the hospital showed diffuse ST-segment elevation (leads V3-V6, I, II, III, and aVF). Basic lab work found a calcium level of 20.4 mg/dl with elevated parathyroid hormone-related protein (PTHrP) of 135 pg/ml. Troponin I remained within normal limits. Serial EKS obtained during the patient's hospitalization demonstrated resolution of the ST elevation as calcium level normalized. This case emphasizes the importance of hypercalcemia as a differential diagnosis for ST-segment elevation and QT shortening when acute coronary syndrome is not present. Awareness of these EKG changes is critical for early diagnosis, recognition, and appropriate treatment.