Background and aim: An unstable angina pectoris is one of the most common types of cardiovascular diseases; although the disease can be medically managed, the patients are always exposed to physical, mental, and social stressors arising from it; therefore, they need nursing interventions including the use of patient’s modern training techniques. Furthermore, self-care can be very helpful for patient care and treatment. Method: In this applied-experimental research, 56 patients with unstable angina pectoris who referred to the admission wards of Firoozabadi Hospital in the city of Shahr-e Rey, Iran, were selected using convenience sampling and were randomly assigned to one of the two control (n = 28) and intervention (n = 28) groups. Subjects in the intervention group received face-to-face and rhythmic breathing training after 2 hours of admission and the acute phase of the disease. Data collection tools included two questionnaires of demographic information and Spielberger's State Anxiety Inventory. The questionnaires were completed before and after the intervention. Results: According to the findings, the use of rhythmic breathing training reduced the anxiety level in the intervention group, which had a long- lasting and significant effect (p> 0.05). Conclusion: Since the use of supportive interventions for rhythmic breathing can reduce anxiety level in the patients with unstable angina pectoris, it is recommended that the nursing managers of health centers take the results of this research into consideration in nursing care programs as an effective way to reduce the anxiety of these patients.
