The goal of this clinical trial is to learn and assess the effect of 10 repetitions of deep breathing exercises every 3 hours compared to 3 repetitions of deep breathing exercises on the sleep quality of patients after heart surgery.

The main questions it aims to answer are:

How does 10 repetitions of deep breathing exercises every 3 hours affect the sleep quality of patients after heart surgery?

Researchers will compare 10 repetitions of deep breathing exercises every 3 hours to 3 repetitions of deep breathing exercises to see if 10 repetitions of deep breathing exercises every 3 hours work to improve sleep quality.

Participants will:

1. Respondents in the intervention group performed 10 repetitions of deep breathing exercises every 3 hours for 3 days.
2. Respondents in the control group performed 3 repetitions of deep breathing exercises for 3 days.

1. Researchers carried out recruitment when the patient had undergone surgery.
2. Researchers determine potential respondents who meet the inclusion criteria.
3. Researchers explain to potential respondents the procedures, objectives, benefits and risks of the research being conducted.
4. Researchers provide time and opportunity for potential respondents to confirm research procedures.
5. The researcher provided an informed consent sheet as a form of respondent's agreement to their involvement in the research.
6. Researchers determine respondents for the intervention and control groups.
7. Respondents do a pretest. The pretest was administered by administering a sleep characteristics and quality questionnaire.
8. Researchers provide education to patients regarding deep breathing exercise procedures.
9. Respondents in the intervention group performed deep breathing exercises with 10 repetitions every 3 hours for 3 days. Respondents in the control group did 3 repetitions of deep breathing exercises.
10. Respondents are monitored in the implementation process using a monitoring form.
11. Respondents who completed the exercise will conduct a post-test assessment.

Inclusion Criteria:

• Patients who have undergone cardiac surgery, both on-pump and off-pump.
• The patient's hemodynamic condition is stable.
• More than equal to 18 years old.
• Able to communicate, read and write in Indonesian.

Exclusion Criteria:

• Patients who receive sleeping medication or sedative therapy.

Outcome assessors were not involved during the intervention process. Respondents were also asked not to inform the outcome assessor of the measures they received.