Hypercalcemia
Also calledHigh calcium · Elevated Ca2+ · High Ca · Raised serum calcium · Hypercalcaemia
Definition
An elevated serum calcium level (a normal total calcium is roughly 8.6 to 10.6 mg/dL). Calcium abnormalities alter the cardiac action potential: high extracellular calcium shortens the action potential plateau (phase 2), so the ST segment shortens or disappears and the QTc interval shortens, and these are its main ECG changes. Severe hypercalcemia can also produce an Osborn-like J wave at normal body temperature.
Sources
- El-Sherif N, Turitto G. Electrolyte disorders and arrhythmogenesis. Cardiol J. 2011;18(3):233-245. pubmed.ncbi.nlm.nih.gov/21660912/
- Otero J, Lenihan DJ. The "normothermic" Osborn wave induced by severe hypercalcemia. Tex Heart Inst J. 2000;27(3):316-317. pubmed.ncbi.nlm.nih.gov/11093425/
- Diercks DB, Shumaik GM, Harrigan RA, Brady WJ, Chan TC. Electrocardiographic manifestations: electrolyte abnormalities. J Emerg Med. 2004;27(2):153-160. doi.org/10.1016/j.jemermed.2004.04.006
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.