Background: Cardiac patients need comprehensive support due to the adverse effects of this disease on different aspects of their lives. Synergy intervention is a model that focuses on patients' requirements. Objectives: This study aimed to determine the eightfold characteristic of cardiac patients based on the synergy model that represent their clinical requirements. Materials and Methods: In this descriptive cross-sectional study, 40 cardiac patients hospitalized at the cardiac care unit (CCU) of Yazd Afshar Hospital were randomly selected. The data were collected by using a two-part checklist including demographic characteristics and also by studying eight characteristics of patients through interviewing and reviewing their records. The results were analyzed using descriptive statistics such as frequency (percentage) and analytical statistics such as Spearman and Mann-Whitney test with the SPSS software, version 18. Results: The results showed that among patients' internal characteristics, reversibility (70.6%), vulnerability (68.6%), and predictability (80.4%) at level 1 (the minimum score) had the highest frequency and stability (49%) and complexity (54.9%) were at level 3 (average score). Among external characteristics participation in decision-making (80.4%) at level 1 had the highest frequency while care (62.7%) and recourses (98%) were at level 3. Conclusions: Ignoring any of the eightfold characteristics based on the synergy model interferes with comprehensive support of cardiac patients. Therefore, it is necessary for professional health practitioners, especially nurses, to consider patients' eightfold characteristics in order to provide quality care.