Why using short V blankings for ICDs?

Dear all,

We received this tracing (N°1) with SmartView from a Livanova Paradym RF SonR CRT. Patient with underlying AVB. This case is interresting:

1) it shows the potential deleterious effect of a burst

2) it illustrates the need of short V blankings for proper VF detection. You can see clearly that the RR intervals are 140ms, which are often said to be "non-physiologic".

3) it also suggests that using a single and very fast VF zone could be dangerous. Indeed, if the blanking would have been longer (not possible for this device, but allowed for Medtronic and SJM), the RR detection would have been 280ms, resulting in the absence of treatment (with a single VF zone >214bpm).

S Ploux