Hypercalcaemia

ECG Changes in Hypercalcaemia

Hypercalcaemia Overview

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

ECG Examples

Example 1

Hypercalcaemia

• Osborn waves in severe hypercalcaemia (4.1 mmol/L)
• Image reproduced from Otero & Lenihan [PMC101092]

Example 2

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

Example 3

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!

Related Topics

• Hypocalcaemia
• Osborn waves
• Measurement of the QT interval
• Hyperkalemia
• Hypokalemia
• Hypercalcemia
• Hypomagnesemia

References

• Slovis C, Jenkins R. ABC of clinical electrocardiography: Conditions not primarily affecting the heart. BMJ. 2002 Jun 1;324(7349):1320-3.
• Otero J, Lenihan DJ. The “normothermic” Osborn wave induced by severe hypercalcemia. Tex Heart Inst J. 2000;27(3):316-7.

Advanced Reading

Online

• Wiesbauer F, Kühn P. ECG Mastery: Yellow Belt online course. Understand ECG basics. Medmastery
• Wiesbauer F, Kühn P. ECG Mastery: Blue Belt online course: Become an ECG expert. Medmastery
• Kühn P, Houghton A. ECG Mastery: Black Belt Workshop. Advanced ECG interpretation. Medmastery
• Rawshani A. Clinical ECG Interpretation ECG Waves
• Smith SW. Dr Smith’s ECG blog.

Textbooks

• Zimmerman FH. ECG Core Curriculum. 2023
• Mattu A, Berberian J, Brady WJ. Emergency ECGs: Case-Based Review and Interpretations, 2022
• Straus DG, Schocken DD. Marriott’s Practical Electrocardiography 13e, 2021
• Brady WJ, Lipinski MJ et al. Electrocardiogram in Clinical Medicine. 1e, 2020
• Mattu A, Tabas JA, Brady WJ. Electrocardiography in Emergency, Acute, and Critical Care. 2e, 2019
• Hampton J, Adlam D. The ECG Made Practical 7e, 2019
• Kühn P, Lang C, Wiesbauer F. ECG Mastery: The Simplest Way to Learn the ECG. 2015
• Grauer K. ECG Pocket Brain (Expanded) 6e, 2014
• Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric 6e, 2008
• Chan TC. ECG in Emergency Medicine and Acute Care 1e, 2004

LITFL Further Reading

• ECG Library Basics – Waves, Intervals, Segments and Clinical Interpretation
• ECG A to Z by diagnosis – ECG interpretation in clinical context
• ECG Exigency and Cardiovascular Curveball – ECG Clinical Cases
• 100 ECG Quiz – Self-assessment tool for examination practice
• ECG Reference SITES and BOOKS – the best of the rest