Sudden cardiac death (SCD) due to a ventricular arrhythmia is a serious cause of cardiovascular death in Canada. The implantable cardioverter defibrillator (ICD) offers high-risk patients a treatment option to reduce the incidence of SCD by delivering an internal shock to restore a normal rhythm, if needed. Definitive evidence has established the effectiveness of the ICD for reducing mortality when used as prophylaxis for SCD (a primary prevention indication). Approximately 3,700 new candidates accrue annually. Practice guidelines define the criteria to determine patient ICD candidacy for primary prevention. However, in addition to SCD risk, ICD candidates may have chronic diseases such as diabetes, renal insufficiency, hypertension, and atrial fibrillation. Thus, balancing the benefits and risks of an ICD can become complex, particularly when competing mortality risks are present. Research has recognized human costs associated with device complications and shocks affecting psychological, health related quality of life (HRQL), and morbidity outcomes. The complexities surrounding the long-term benefits/risks, complications, replacements, and shocks, warrant decision support to prepare patients to make decisions. In Canada, there is no clear framework to support patients' decision-making in the context of ICD treatment options. Decision support, using a decision aid, could moderate treatment related uncertainty and prepare patients to make active, informed, quality decisions.