ECG of the Week - 28th July 2014 - Interpretation

This week's ECG is from a 29 yr old male who presented complaining of vomiting, dizziness and felling 'vague'. 
You can check out his venous blood gas over at Emergucate's Lab Case 28 here.
Check out the comments on our original post here.

Click to enlarge

Rate:

• ~110 bpm

Rhythm:

• Regular
• Sinus rhythm

Axis:

• Normal

Intervals:

• PR - Normal (~120ms)
• QRS - Normal (100ms)
• QT - 440ms (QTc Bazette 550-600 ms)

Segments:

• ST Elevation leads aVR, aVL and V1
• ST Depression leads II, III, aVF, V4-6

Interpretation:

• QTc Prolongation and ST segment changes in the setting of significant acid-base disturbance
• Severe alkalaemia

What happened ?

The patient's additional biochemistry revealed a primary hypochloraemic metabolic alkalaemia with significant acute renal failure due to recurrent vomiting.
He received titrated benzodiazepines for agitation and following careful re-hydration and electrolyte monitoring the patient's ECGs normalised.
Subsequent upper GI endoscopy revealed an inflammatory gastric outlet obstruction as the cause of his recurrent vomiting.

References / Further Reading

Life in the Fast Lane

• Metabolic alkalosis overview
• Hypocalcaemia ECG features

Textbook

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