ECG of the Week - 23rd November 2015 - Interpretation

This ECG is from a 75 yr old male who presented complaining of lethargy, nausea and shortness of breath. You have no old ECG's for comparison.

Click to enlarge

Rate:

• 66

Rhythm:

• Regular
• No P waves present
• Accelerated Idioventricular Rhythm (AIVR)

Axis:

• Normal

Intervals:

• QRS - Prolonged (160ms)

Segments:

• Discordant ST segment changes
• Excessive depression in lead V5 and excessive elevation V3 (just on -0.25 ST elevation / QRS depth)

Additional:

• LBBB Morphology
• Deep S in V1-3
• Broad R wave in lateral leads
• T waves massively disproportionate and peaked
• Note in leads V5-6 terminal portion of T wave becomes positive

The key abnormalities on this ECG are:

• AIVR
• LBBB with abnormal ST changes
• Massive peaked T waves

Broad differentials would include

• Ischaemia
• Drug toxicity
• Acid-base disturbance
• Electrolyte abnormality

At first glance I'd favour hyperkalaemia as the culprit and an urgent VBG was taken - K 8.8 mmol/L !

I unfortunately don't have a follow-up ECG and I expect following treatment sinus rhythm was restored and the T wave changes normalised. I would be interested to know if the LBBB was longstanding or secondary to the hyperkalaemia,

References / Further Reading

Life in the Fast Lane

• AIVR
• Hyperkalaemia
• LBBB

Textbook

• Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.