Since the introduction of implantable cardiac pacemakers in 1958 and implantable cardioverter-defibrillators in 1980, these devices have been proven to save and prolong lives. Pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy are deemed life-sustaining therapies. Despite these life-saving technologies, all patients ultimately will reach the end of their lives from either their heart disease or development of a terminal illness. Clinicians may be faced with patient and family requests to withdraw these life-sustaining therapies. The purpose of this article is to educate clinicians about the legal and ethical principles that underlie withdrawal of life-sustaining therapies such as device deactivation and to highlight the importance of proactive communication with patients and families in these situations.