Life‐threatening and life‐saving inappropriate implantable cardioverter defibrillator shocks

Figures

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  Figure 1. EGMs of the episode are shown in consecutive strips. The upper channel shows the far‐field, the middle one corresponds to the near‐field (ventricular tip‐ ventricular ring), and the lower one to the markers. Panel A: A sudden shortening in basal cycle length that reach VF zone is shown in the near‐field channel, while the far‐field channel remains in the patient´s basal rhythm. Panel B: VF detection criteria are met, and an unsynchronized shock is delivered inducing VF (change in far‐field channel). Panel C: VF is registered in the far‐field channel, while AF is undersensed in the near‐field and a subsequent shock is canceled. Activador = VF therapy activated and start of charging, EGMs = intracardiac electrograms, F = ventricular fibrillation detection, FV = VF detection criteria met, Regreso a sinusal = sinus rhythm restored, VF = ventricular fibrillation, VS = ventricular sensing.

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  Figure 2. EGMs of the episode are shown in consecutive strips. The upper channel shows the far‐field, the middle one corresponds to the near‐field (ventricular tip‐ ventricular ring), and the lower one to the markers. Panel A: VF is shown in far‐field channel, while unstable low signals are registered in the near‐field channel. Panel B: A stable period of VF detection that fulfilled diagnosis criteria led to a shock that limits VF (see far‐field channel). Panels C and D: Redetection of AF in the near‐field channel within the VF zone induces a shock that restores sinus rhythm. Activador = VF therapy activated and start of charging, EGMs = intracardiac electrograms, F = ventricular fibrillation detection, FV = VF detection criteria met, VF = ventricular fibrillation VP = ventricular pacing, VS = ventricular sensing, Regreso a sinusal = sinus rhythm restored.

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  Figure 3. The panel A shows the chest X‐ray in the emergency department. The ventricular lead is dislodged into the right atrium. The panel B corresponds to the routine X‐ray after repositioning the ICD lead.