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

TOP 100 ECQ QUIZ LITFL 003

Describe and interpret this ECG

ECG ANSWER and INTERPRETATION

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

Diagnosis

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.


CLINICAL PEARLS

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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