This tracing corresponds to an oversensing caused by an electric scalpel during a hip surgery, the ICD not having been deactivated. When an ICD recipient undergoes a surgical intervention, the surgeon must be advised to use the electric scalpel in bipolar mode, for brief durations and to place the grounding plates away from the pulse generator so as to maintain the ICD system outside of the field generated by the electric scalpel. The ICD should be temporarily deactivated in order to completely eliminate the risk of interference, with the patient being monitored with an external defibrillator available nearby if necessary. Two options can be chosen to disable the device: application of a magnet to the pulse generator or deprogramming of the device. The application of a magnet is generally preferred because

1. in case of a occurrence of a true arrhythmia compromising the survival of the patient, the medical team can immediately reactivate the system by removing the magnet (resumption of sensing of tachycardias immediately upon removal of the magnet);
2. absence or delay in the reactivation of therapies are not uncommon when the ICD has been deprogrammed.