VF shock in a MADIT II patient

Trace category: 
EGM
Device/Field: 
Home monitoring
Company: 
Medtronic

 

53 old man implanted in 2010 with a single-coil transvenous cardioverter defibrillator system (Medtronic Virtuoso 2). EF was 30% at that time related to the occlusion of both the left circumflex and the right coronary artery (primary prevention). Narrow QRS duration. His medication is: Bisoprolol 3.75mg, Candesartan 24mg, Atorvastatine 40, Clopidogrel 75. This patient never experienced any ICD treatment until the following remote transmission. . I have three comments:

1/Yes, ICD save lifes in primary prevention although a VF shock is an uncommon initial event.

2/ The VF is terminated by the second shock. What do you advise? To program a cathodal polarity for the first shock (AX>B)? To change the box for a high energy device? To change the lead?...

3/ What do think about the initial rhythm before the VF onset?

Thanks for your inputs,

Sylvain Ploux

Nice tracing!!!!

before the acceleration in the VF zone, the rhythm is already fast (difficult to differentiate VT and SVT since we do not have the EGMs) but slower than the different tachy zones. It may be a long-lasting episode of non treated VT inducing hemodynamic deterioration; the arrhythmia then degenerates in a very fast VT. The fisrt shock is not only inefficient but also turns the monomorphic very fast VT (ventricular flutter) into an episode of real VF (polymorphic). The second shock is efficient.      

In this patient, I would change the tachy zones (VT zone 150 bpm) to treat the initial arrhythmia if the discriminators favor a VT/SVT.