 2. When VF induction is performed, sensing configuration would be tested in a randomized fashion, unblinded to the operator. The untested configuration would then be tested during second VF induction. Both tests would be performed at a sensitivity setting of 1.2mV, with a number of intervals to detection NID of 2432. Final programming polarity will be left at the initially tested polarity first DFT test, unless the operator sees a need to program differently for patient safety reasons. 