Incorrect NSVT discrimination during AF

This patient was seen for a routine CRT-D  follow up and had not had any symptomatic events. The patient was in permanent AF and had one episode of NSVT. VT/VF detection was withheld due to Afib/AFlutter criteria. Wavelet match was 0% (wavlet was not asked). So I just throught it was an interesting  just wanted to get peoples thought and idea into why this occured.

(I have been in touch with our Medtronic technical rep already regarding this)

Physician advice: 
Trace category: 
Sylvain Ploux's picture

Pr Hooker,

Thank you for the tracing. I suspect that PR logic does not consult the Morpholog if he diagnoses a SVT in a first place. Wavelet (Morpholog) is used to correct (eventually) a VT diagnosis from the PR logic (exept if V>A). This is why the diagnosis was AF despite the 0% match.

I hope this will help.

Don't hesitate to submit again.



In medtronic devices, Wavelet algorythme is generally used for  VVI ICD . Also medtronic staff advice against to let all of the algorythme to work together. Some of them could inhibit to the others  as seen in that case. Probably PR logic intervened wavelet.