ECG of the Week - 7th May 2018 - Interpretation

The following ECG is from an unknown female who was found collapsed. She has had a seizure en route to the hospital and her current GCS is 7 (E=1 M=4 V=2).

 

Click to enlarge

Rate:

• 167 bpm

Rhythm:

• Regular
• Non-sinus
• Potential atrial activity seen within some QRS complexes

Axis:

• Inferior

Intervals:

• QRS - Prolonged (100-120 ms)
• QT - 300-320ms (QTc Bazette 380-400 ms)

Additional:

• Terminal R' wave in lead aVR
• Absent lead V6

Interpretation:

• ECG features suggestive of sodium-blockade
• Tachycardia
• QRS Prolongation
• Terminal R wave lead aVR
• Clinical scenario consistent 
• Seizure 
• Altered conscious level

What happened ?

 The patient was treated with sodium bicarbonate prior to RSI and intubation. Post intubation they were hyperventilated to a target pH of 7.5 and serial ECG's showed resolution of QRS prolongation and normalisation of lead aVR.The patient was extubated the next day and revealed they had taken an intentional amitriptyline overdose. 

References / Further Reading

 

Life in the Fast Lane

• Sodium Channel Blockade

Textbook

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