An implantable cardioverter-defibrillator (ICD) detects abnormal, potentially deadly heart rhythms and automatically corrects the faulty rhythm. For the insertion, which is done under local anesthesia, the surgeon places electrodes in the patients heart through one of the large veins in the chest and tests them. Then a small generator is placed under the skin in the chest. If and when this device senses an abnormal rhythm, the ICD restores the hearts normal beat, either by delivering a shock to the heart muscle or by using repeated low-energy signals (cardiac pacing). The device also records when abnormal rhythms occur and when shocks are administered. |