ECG of the Week - 17th August 2015 - Interpretation

This ECG is from an 85 year old male who presented to the Emergency Department confused and drowsy. He had a recent diarrhoeal illness and had been non-compliant with his long-term medications. 
On arrival his vital signs were: SBP 85 RR 34 Sats 90% RA GCS 12.
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Rate:

• ~185 bpm

Rhythm:

• Regular
• Nil atrial activity visible

Axis:

• Extreme / NW Axis

Intervals:

• QRS - Normal (80ms)
• QT - 260ms

Segments:

• ST Elevation leads I, aVL, V1
• ST Depression leads II, III, aVF, V2-6

Additional:

• Late R wave transition
• High voltages in infero-lateral leads with deep S waves

Interpretation:

• Narrow complex tachycardia in patient with cardiovascular compromise

What happened ?

Prior to DC cardioversion the patient was treated with oxygenation, iv volume replacement and adenosine bolus with resultant reversion to sinus rhythm.
The ST changes resolved rapidly following cardioversion and were likely due to demand ischaemia. The patients resting ECG showed extreme axis deviation with persisting high inferior QRS voltage and deep S waves.
The patient was admitted to hospital for management of his multiple medical issues and social situation.

References / Further Reading

Life in the Fast Lane

• SVT
• SVT vs VT

Textbook

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