A defib­ril­la­tor (also known as an implantable car­diovert­er-defib­ril­la­tor, or ICD) is a device designed to treat patients diag­nosed with or who are at risk for life-threat­en­ing heart rhythm dis­or­ders. The device will pro­vide a shock if it detects these arrhyth­mias. Thou­sands of lives have been saved due to the use of ICDs. The surgery is gen­er­al­ly done with intra­venous seda­tion and takes about an hour.