Cardiac arrest is an abnormal heart rhythm that causes the heart to suddenly stop beating. Doctors treat cardiac arrest by using electric shocks that help the heart return to a normal rhythm. Doctors can apply the electricity externally to the chest or can place an electrical device under the skin to detect abnormal heart rhythms and immediately apply an electric shock to the heart. These devices are called implantable cardioverter defibrillators or ICDs. The devices can prolong life, which is usually the desired goal. However, patients with ICDs who are seriously ill and nearing death may no longer want to prolong life or suffer the discomfort that ICD shocks cause. It is not known how often doctors discuss turning off ICDs with patients nearing death who have the device. Turning off the device would let patients die a less uncomfortable death without the discomfort of electric shocks.