With the efficacy of implantable cardioverter defibrillator (ICD ) therapy well established, the survival time of recipients of this technology must be interpreted more broadly. It is important to better understand how ICD recipients perceive their dependence on this life saving technology and how these perceptions influence their Health Related Quality of Life (HRQL). The purpose of this cross sectional, predictive study is to test a causal model that may explain the link between attitudes towards dependency on technology and HRQL in a sample of adult ICD recipients. The hypothesized model consists of seven variables: attitudes towards technology dependency; age; gender; illness history; illness representation; symptom distress; and HRQL. Adult subjects (greater than 18 years) who have received an ICD will be asked to participate. Subjects will complete a self-administered, mailed questionnaire that includes five instruments: 1) The Medical Outcomes Short Form 36 Survey Version 1.0; 2) The Important Concerns and Distress Questionnaire; 3) The Illness Perception Questionnaire; 4) The Dependency on Technology Scales; 5) Demographic Questionnaire. The model will be tested statistically by use of Structural Equation Modeling techniques. The definitive goal of this study is to develop a theoretically meaningful and statistically well-fitting model that specifies how dependence on technology influences HRQL. The hypothesis for this study is that the full structural equation model fits data from the sample of adult ICD recipients.