Interesting pacemaker strip...

~~Patient was implanted with a dual chamber Medtronic pacemaker because of AV-block after RF ablation for AVNRT.

During device interrogation with testing we see this EGM.

What's going on on this strip? ECG is not connected (noise), EGM is the ventricular channel.

If you know the answer, perhaps you can also answer this question: is the patient at risk for PMTs?

Physician advice: 
Trace category: 
Sylvain Ploux's picture

Nice one Marc,

To help I guess you can tell that the test was done in VVI mode, right?


This was sent to me by a colleague from another hospital so I don't have more information.

But looking at the device behaviour, I assume it's VVI. :)

Pierre Bordachar's picture

Hi Mark, the pacing mode during the threshold test must be VDI 90bpm; when there is a ventricular capture, there is a 1/1 retrograde conduction explaining the aspect VP-AS; when you loose the ventricular capture, you see a slowing of the a trial rhythm ; there is a retrograde conduction, so there is a risk of PMT; at the end of the test permanent pacing mode (DDD) 


Sylvain Ploux's picture


Unfortunatlty the management of PMT is going to be hard since Medtronic pacemakers need a VP-AS<400ms for a PMT to be recognized. I see that in your case VP-AS is above this limit...