The present study was conducted based on the interventional-educational approach. The statistical population of this study consisted of patients who were candidates for open heart surgery referred to the hospital, in which 60 patients were randomly assigned to two groups of virtual reality and ordinary video. The random allocation was concealed by applying, the method of opaque sealed envelopes with a random sequence. After the visit, the patients received a number according to the priority of their arrival at the center, that corresponded to the numbers on the sealed envelopes. There was one of codes A and B inside the sealed envelopes. This sequence was identified by a non-sampler using www.Randomizer.org. Each of the codes represented the study group in which the individual was placed. Code A represented the virtual reality intervention group and Code B represented the conventional video intervention group. Inclusion criteria were being candidates for open heart surgery, communication skills, literacy, the age range of 30–70 years, lack of severe hearing and vision problems, willingness to participate in the study, and no history of mental illness. Exclusion criteria included being in an emergency situation (e.g., cardiac arrhythmia and respiratory distress) and using and receiving narcotics and sedatives. Data collection tools were (1) demographic characteristics questionnaire, which included age, sex, marital status, level of education, medical history, and smoking according to the research objectives. (2) The Spielberger State-Trait Anxiety Inventory (STAI); this tool consists of 20 items to assess a person’s feelings at “the moment and the time to respond.” The four-choice expressions are scored as very low, low, high, and very high. The minimum and maximum score obtained from the questionnaire is 20–80. Scoring is as follows: mild anxiety rate from 20 to 31, moderate to low anxiety: 32–32, moderate to high anxiety 43–53, moderately severe 54–64, severe: 65–75, and very severe:76 and above. In Mehram’s (Borang et al. 2017) study, the internal consistency of both scales was calculated via Cronbach’s α on a group of 600 people. The Cronbach’s α coefficients of the State Anxiety Scale and the Breggy Anxiety Scale were reported to be 0.91 and 0.92, respectively. For the total test, Cronbach’s α coefficient is 0.94. In this study, The content of both videos is the same, but the ordinary video was recorded with a normal camera and the virtual reality was recorded with a Nikon 360° camera. The duration of the video is 4 minutes and 35 s.

In the video, the physical space of the operating room was shown. The video starts from the entrance door of the operating room and the camera moves from the corridor and reaches the room where the operation is performed. Next, the researcher entered the room and explained the application of the devices used in open heart surgery, (i.e., the ventilator, cardiopulmonary pump, monitor, and operating table) and how to place the patient on the operating bed to participants in simple language. At the end of the video, the researcher explained that the patient was transferred to the intensive care unit (ICU) after the operation, wherein treatment was continued. The virtual reality video was displaced to the samples, using the TSCO virtual reality glasses (model TVR 568). To this end, the video was placed in the virtual reality glasses and displayed with the phone device along with the virtual reality video player software. For the normal video group, the same video made by the iPad was displayed. To start the study, the researcher referred to the men’s and women’s cardiac surgery wards of the Cardiovascular Hospital the day before the operation. After explaining the study’s objectives and obtaining informed consent to participate in the study, the participants were asked to complete the demographic information form, and the medical record was prepared. Afterward, the SATI was provided to the samples to complete by themselves, and the vital signs of the samples were measured by the researcher and recorded. In the next step, an educational film was displayed for two groups. Some of the samples in both groups requested to watch the videos again, which was done. Finally, on the day of surgery, the researcher reappeared in the wards of the study center. About 2 h before receiving the prescribed drugs to prepare the patient for surgery, the SATI was completed by both groups, and the researcher measured and recorded the vital signs. Finally, the data were entered into SPSS-25 software.