- 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
Causes of Hypercalcaemia
- Hyperparathyroidism (primary and tertiary)
- Bony metastases
- Paraneoplastic syndromes
- Milk-alkali syndrome
- Excess vitamin D (e.g. iatrogenic)
ECG Changes in Hypercalcaemia
- Osborn waves caused by severe hypercalcaemia (4.1 mmol/L).
- Image reproduced from Otero & Lenihan (see references below)
- Hypercalcaemia causing marked shortening of the QT interval (260ms).
- Image originally featured in Kyuhyun (K.) Wang’s excellent Atlas of Electrocardiography.
- 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!
- Slovis C, Jenkins R. ABC of clinical electrocardiography: Conditions not primarily affecting the heart. BMJ. 2002 Jun 1;324(7349):1320-3. Review. PMID: 12039829. Full text.
- 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.
- Brady WJ, Truwit JD. Critical Decisions in Emergency and Acute Care Electrocardiography
- Hampton, JR. The ECG In Practice, 6e
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric, 6e
- Wagner, GS. Marriott’s Practical Electrocardiography 12e
- Chan, TC. ECG in Emergency Medicine and Acute Care
- Wang, K. Atlas of Electrocardiography
- Mattu, A. ECG’s for the Emergency Physician
LITFL Further Reading
- ECG BASICS — Waves, Intervals, Segments and Clinical Interpretation
- ECG A to Z by diagnosis –alphabetical diagnostic approach to the ECG
- ECG CLINICAL CASES — ECG’s placed in clinical context with a challenging Q&A approach
- 100 ECG Quiz — Self-assessment tool for examination practice
- ECG Reference SITES and BOOKS — the best of the rest
- LITFL ECG IMAGE Database — Searchable database of LITFL ECG’s
- ECG and Cardiology Eponymous Syndromes — Cheats guide to eponymous emancipation
- ECG Exam Template — a framework for answering ECG exam questions.