Developing a Digital Aid to Improve ICD Decisions

Developmental Testing will attempt to abide by eligibility criteria identical to the planned criteria for the subsequent RCT, but may strategically deviate from these criteria to enhance the testing and development process. Inclusion Criteria: * Meets or approximates minimal criteria for primary prevention ICD placement. ● Left Ventricular Ejection Fraction (LVEF) \<35%. * Clinical diagnosis of Heart Failure: * Patients with severe ischemic dilated cardiomyopathy and underlying NYHA * Class II or III Heart Failure, OR, Patients with severe nonischemic dilated cardiomyopathy and underlying NYHA Class II or III Heart Failure. * Age ≥ 70 years old. * Able to consent in English, Mandarin or Spanish and follow study instructions. Exclusion Criteria: The exclusion criteria include any of the following: * Past ICD implantation (not including pacemakers). * Any indication for secondary prevention of SCD via ICD implantation. * History of mechanical valve replacement. * History of recent myocardial infarction within the last 40 days. * History of recent revascularization within the past 90 days. * History of familial or genetic disorders with a high-risk of ventricular arrhythmias, such as the long QT syndrome (LQTS) or hypertrophic cardiomyopathy (HCM). * Any factors contraindicating ICD placement. * Less than 6 months life expectancy and other clinical consideration, * Unwilling or unable to consider ICD, * Any contraindications to ambulati