Since the approval of expanded coverage for primary prevention by CMS along with the requirement for registry participation in early 2005, the ICD implant volume did not show an apparent increase as expected by many. Instead, a flat growth of ICD sales has been observed over the last 2 years. Several explanations have been offered by various sources. Some attribute the slow growth to the loss of confidence among the referring physicians, patients, and family members as the result of the multiple industry recalls. Others claim that only a small portion of the eligible candidates receive ICD therapy because of poor awareness of the ICD benefit among the referring physicians and the public (the Cambridge Heart Commercial). However, the Medtronic campaign to promote public awareness has had little impact on the volume of ICD implants. Another group of people suspect that the cardiologists have not paid enough attention to the patients' candidacy for ICD therapy because they tend to focus on the patients' ongoing symptoms not proactive prevention. Thus,an active screening program may identify a significant number of patients who will benefit from ICD therapy. However, there has been no comprehensive study that has evaluated the impact of active screening on the ICD implant volume, the percentage of eligible ICD patients without ICDs and the reasons for not receiving ICDs.