ECG of the Week - 9th November 2015 - Interpretation

This ECG is from a 55 yr old male who presents with several weeks of intermittent dizziness. He has an implanted loop recorder (ILR) in-situ and is under cardiological investigation for these episodes.

Click to enlarge

Rate:

• 54 bpm

Rhythm:

• Subtle irregularity

Axis:

• Normal

Intervals:

• PR - Short (~120ms)
• QRS - Normal (90ms)
• QT - 460ms (QTc Bazette 440 ms)

Segments:

• No significant change

Additional:

• U waves V2-3
• Normal P wave axis
• No delta waves
• Note artifactual 'spike' preceding last p wave 

Interpretation:

• Sinus bradycardia
• Short pr without features of pre-excitation or retrograde p wave conduction

What happened ?

The patient's ILR revealed multiple episodes of symptomatic junctional bradycardia and he underwent an uneventful PPM insertion. I'm certainly encountering more patients with ILS's in-situ and it's worth reading the following eMedicine summary on these devices:

eMedicine

• Implantable Loop Recorder

References / Further Reading

Life in the Fast Lane

• Junctional Bradycardia
• PR Interval

Textbook

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