Hypercalcaemia

Hypercalcaemia causing marked shortening of the QT interval (260ms). Image originally featured in Kyuhyun (K.) Wang's excellent Atlas of Electrocardiography.

Definitions

• Hypercalcaemia is defined as a serum corrected calcium > 2.7 mmol/L
• Severe hypercalcaemia is a corrected calcium > 3.0 mmol/L

ECG Changes in Hypercalcaemia

• The main ECG abnormality seen with hypercalcaemia is shortening of the QT interval
• In severe hypercalcaemia, Osborn waves (J waves) have also been reported

Osborn waves caused by severe hypercalcaemia (4.1 mmol/L). Image reproduced from Otero & Lenihan (see references below)

Causes of Hypercalcaemia

• Hyperparathyroidism (primary and tertiary)
• Myeloma
• Bony metastases
• Paraneoplastic syndromes
• Milk-alkali syndrome
• Sarcoidosis
• Excess vitamin D (e.g. iatrogenic)

Related Topics

• Hypocalcaemia
• Osborn waves
• Measurement of the QT interval

Further Reading

• ECG BASICS – Waves, Intervals, Segments and Clinical Interpretation
• ECG CLINICAL CASES – Your favourite ECG’s placed in clinical context with a challenging Q&A approach
• ECG and Cardiology Eponymous Syndromes – Cheats guide to eponymous emancipation
• ECG Reference Sites on the WEB – the best of the rest

Author Credits

References

• 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).