ECG of the Week - 3rd October 2016 - Interpretation

The following ECG is from a 78yr old female who presented to the Emergency Department with a 1 day history of cough, confusion, fever and dysponea. She has a prior medical history of COPD, PVD and rheumatoid arthritis.

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Rate:

• Mean ventricular rate 114 bpm
• 
  

Rhythm:

• Complexes # 1-4 & # 7-13
• Sinus rhythm
• Normal PR interval
• Nil evidence of pre-excitation in QRS complexes
• Complexes # 5-6
• Similar morphology to sinus complexes
• Nil clear preceding P wave
• Followed by compensatory pause
• Likely premature junctional complexes
• Complexes # 14-19
• Onset of narrow complex tachycardia
• Evidence of underlying P waves
• QRS alternans

Axis:

• Normal

Intervals:

• QRS - Normal (100ms)

Segments:

• ST depression leads I, II, V4-6

Interpretation:

• Sinus rhythm 
• Onset of narrow complex tachycardia captured

What happened ?

The patient had pneumonia and whilst in the Emergency Department has several self-terminating runs of regular narrow complex tachycardia with rates up to 190 bpm.
Her pneumonia was treated with fluid resuscitation, antibiotic therapy and correction of hypoxia. The runs of SVT were treated with electrolyte correction and calcium channel blocker therapy.

References / Further Reading

Life in the Fast Lane

• SVT
• Premature junctional complex

Textbook

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