- Normal serum corrected calcium = 2.1 – 2.6 mmol/L
- Mild hypercalcaemia = 2.7 – 2.9 mmol/L
- Moderate hypercalcaemia = 3.0 – 3.4 mmol/L
- Severe hypercalcaemia = greater than 3.4 mmol/L
ECG Changes in Hypercalcaemia
Causes of Hypercalcaemia
- Hyperparathyroidism (primary and tertiary)
- Bony metastases
- Paraneoplastic syndromes
- Milk-alkali syndrome
- Excess vitamin D (e.g. iatrogenic)
A case of severe hypercalcaemia
This is the ECG of a 41-year old man with a parathyroid adenoma who presented to ED critically unwell with a serum calcium of 6.1 mmol/L. He suffered a VF arrest not long after this ECG was taken.
The ECG shows:
- Bizarre-looking QRS complexes
- Very short QT interval
- J waves = notching of the terminal QRS, best seen in lead V1
Many thanks to Dr James Hayes, FACEM, for this fantastic ECG!
- Kumar P, Clark M. Kumar & Clark’s Clinical Medicine (7th edition). London: Elsevier (2009).
- Otero J, Lenihan DJ. The “normothermic” Osborn wave induced by severe hypercalcemia. Tex Heart Inst J. 2000;27(3):316-7. PMID: 11093425. Full text.
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice (6th edition), Saunders 2008.
- Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.
- Wang, K. Atlas of Electrocardiography (2011).