ECG of the Week - 2nd October 2017 - Interpretation

The following ECG is from a 16 yr old male who presented with episodes of feeling unwell, nauseous and dizzy. He is on no medication and was investigated for palpitations 7 yrs ago without cause identified.

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Rate:

• Initial ventricular rate ~150-160 bpm
• Period of ventricular bradycardia
• Subsequent increase in ventricular rate
• Atrial rate variable ~100-110 bpm

Rhythm:

• Initial 7 complexes
• Mix of sinus and accelerated junctional rhythm
• Next 2 ventricular complexes
• 2:1 AV block
• Period of complete AV block / high grade AV block
• Next 2 ventricular complexes
• SInus rhythm
• Followed by accelerated junctional rhythm

Axis:

• Right axis deviation

Intervals:

• PR - Normal
• During periods of sinus conduction
• QRS - Normal

Additional:

• Dominant R waves leads V1-2
• Meets voltage criteria for biventricular hypertrophy
• Nil features of strain or Q waves

Interpretation:

• Tachy-brady syndrome
• Accelerated junctional tachycardia
• High grade AV block
• Patient was symptomatic during these episodes of bradycardia complaining of dizziness and nausea. During episodes of tachycardia he experienced palpitations.

What happened ?

He had no reversible cause including culprit medications and normal biochemical assessment. He was transferred for tertiary managment and following further investigation including EP study underwent a PPM insertion.

References / Further Reading

Life in the Fast Lane

• High grade AV block
• 2:1 AV block
• Accelerated junctional rhythm 

Textbook

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