Aborted charge

Comments

The electrical grid is associated with a 50 Hz signal (in Europe, in the USA it is 40 Hz) which may be oversensed by ICDs when the patient is in contact. This may occur when the patient is in skin contact with the powergrid. Often because of insufficient isolated electrical appliances or through wet surfaces which are somehow connected to the electricity. While there are filters in place which attempt to avoid oversensing of these extremely fast signals, there is still a risk of inappropriate therapy. Since these signals may have significant amplitude and are always extremely fast, altering the sensitivity or the zones is often of little use. The only solution is to interrogate the patient on what activities were performed during the oversensing episode, in an attempt to identify the source. This activity (for example cleaning a poorly isolated caravan) should then be avoided in the future. Remote monitoring is perfect for this, as these episodes may be transmitted as an alert, and the remote monitoring staff may interrogate the patient soon after the episode, increasing the possibility that the patient remembers the activity. While oversensing of 50 Hz may be associated with an inappropriate shock (not so much ATP because too fast), the patient will most often stop the activity at once, eliminating the risk of suffering from multiple shocks.