ECG Changes in Hypercalcaemia
ECG-QT-changes-Hypocalcaemia-Hypercalcaemia 2
Hypercalcaemia causes shortening of the QT interval

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
ECG Osborn waves in severe hypercalcaemia


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
ECG Hypercalcaemia 2

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!


Advanced Reading



LITFL Further Reading


Emergency Physician in Prehospital and Retrieval Medicine in Sydney, Australia. He has a passion for ECG interpretation and medical education | ECG Library |

MBBS (UWA) CCPU (RCE, Biliary, DVT, E-FAST, AAA) Adult/Paediatric Emergency Medicine Advanced Trainee in Melbourne, Australia. Special interests in diagnostic and procedural ultrasound, medical education, and ECG interpretation. Editor-in-chief of the LITFL ECG Library. Twitter: @rob_buttner

One comment

  1. Example 3 shows a limb lead error (left arm – right arm reversal)
    To correct this:
    Inverted lead I
    II and III switch places
    aVR and aVL switch
    Yes the ECG would still be abnormal but not quite as abnormal as it appears here.

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