Middle-aged diabetic patient presenting with shortness of breath. Clinical evidence of pulmonary oedema.

Describe and interpret this ECG


Main Abnormal Findings

  • Severe bradycardia of 36 bpm
  • Rhythm is difficult to ascertain — appears irregular (?slow AF) although there are some small-voltage P waves seen in V1-2
  • Broad QRS complexes with an atypical LBBB morphology
  • Subtle symmetrical peaking (“tenting”) of the T waves in V2-5


The combination of bradycardia, flattening and loss of P waves, QRS broadening and T wave abnormalities is highly suspicious for severe hyperkalaemia. This patient had a potassium of 8.0 in the context of anuric renal failure.


When you see the combination of…

  • Bradycardia
  • Blocks — e.g. AV block, bundle branch blocks
  • Bizarre QRS complexes

…. think hyperkalaemia!

The push-pull effect
  • Hypokalaemia creates the illusion that the T wave is “pushed down”, with resultant T-wave flattening/inversion, ST depression, and prominent U waves
  • In hyperkalaemia, the T wave is “pulled upwards”, creating tall “tented” T waves, and stretching the remainder of the ECG to cause P wave flattening, PR prolongation, and QRS widening

TOP 100 ECG Series

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) 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

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