ECG of the Week - 2nd April 2018 - Interpretation


The following ECG is from a 74yr old male who presented following several episodes of chest pain and dizziness. 

Click to enlarge

Rate:

• 66 bpm

Rhythm:

• Nil p waves
• Fibrillation waves best seen leads V1 & V3
• Regular ventricular rhythm 
• Each ventricular complex associated with a pacing spike
• Best seen leads II, aVR, aVF, V1, V3-6

Axis:

• Left
• Superiorly at ~ -70 degrees

Intervals:

• QRS - Prolonged (200ms)

Additional:

• Appropriate discordant T wave and ST changes
• No evidence of excessive discordance
• Note QRS relatively low voltage in leads V1-2
• Need to check ECG lead placement
• Compare with old ECGs
• Monitor for dynamic change

 

Interpretation:

• Ventricular paced rhythm
• All complexes paced
• Absence of native rhythm
• Lead placement likely right ventricular apex
• Nil atrial activity seen

 Quick pacemaker points

 

Remember a few things about patients with pacemakers.

Pacemaker activity visualised on the 12-lead is dependent on several factors:

• Pacemaker programming
• Patient's current native rhythm
• Wire placement
• Appropriate wire position and function
• Patient's other activity co-morbidities - drug toxicity, ACS, electrolyte abnormality etc.

What might you see:

• No pacing activity / Native rhythm only
• Atrial pacing only
• Ventricular pacing only
• Combination of atrial and ventricular pacing
• Combination of all the above

 

References / Further Reading

Life in the Fast Lane

• Pacemakers

Textbook

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