The implantable defibrillator and the emergency physician

The automatic implantable cardioverter defibrillator (AICD) is a proven therapy for preventing the potentially lethal consequences of recurrent ventricular arrhythmias. Given the ever-increasing number of patients who have these devices, it can be anticipated that an increasing number of these patients will likely present to emergency departments with problems associated with this therapy. We review normal automatic implantable cardioverter defibrillator function and focus on the evaluation and treatment of problems that may bring a patient to the ED. Included are interaction with the device by magnets, assessment of the propriety of shocks received by the patient, and what to do when patients state they have received a shock from the device. An algorithmic approach is presented to facilitate management of these patients.