Inappropriate defibrillator shock due to EMI despite noise reversion and SecureSense - What is the mechanism?

Figures

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  Fig. 1. 12 lead ECG showing ventricular paced rhythm with wide fragmented QRS fitting with ischemic cardiomyopathy.

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  Fig. 2A. Stored electrograms showing noise in both channels. The discrimination (FF) channel shows more distinct EGM’S.

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  Fig. 2B. Stored EGM shows treated episode in the VF zone. It shows oversensing of noise which stops after 15J shock and return of sensed rhythm.

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  Fig. 3. After the paced/sensed R wave ‘threshold starts’ at programmed decay delay. 1) threshold start (sensed 50% R wave/1 mV if paced) 2) If decay delay programmed 0 ms (hypothetical) 3) decay delay at 95 ms (this case).