This week’s electrogram interpretation:
A 22-year-old male came into the EP lab with complaints of palpitations. During the EP study, the following rhythm was induced.
The HRA, His, CS, and RV catheters are in their standard positions.
#1 – What rhythm was induced?
#2 – What is observed that makes this rhythm more dangerous?
#3 – What is the treatment?
Answer
Atrial Fibrillation with WPW
#1: The patient is in atrial fibrillation. Notice the chaotic atrial activity on the HRA and CS channels. There is also an irregularly irregular ventricular response.
#2: Notice the wide QRS complex. This is not a normal bundle branch block aberrancy. This is preexcitation of the ventricle via an accessory pathway. The QRS appearance is changing continually due to the varying degrees of preexcitation as activation is over the AV node and AP.
#3: Treatment should be aimed at ablation of the accessory pathway. The risk of pathways that can conduct in the antegrade direction is that it bypasses the AV node and the patient may be at risk of SCD (sudden cardiac death).
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If you like this, find hundreds of electrograms to interpret in our Understanding EP workbook – included in the Understanding EP book set.
For more information: EP Essentials – Understanding EP: A Comprehensive Approach
