The Mental Imaging group will receive olfactory mental imagery technique and vagus breathing therapy for 1 hour in the morning and evening on the 1st, 2nd, 3rd and 4th days after surgery. In addition, the standard care (breathing exercises with Triflo, early walking, frequent position changes in bed) and treatment plan, which are the standard protocol of the Cardiovascular Surgery Service, will be continued by the clinic nurse and physician.

The control group was given no intervention other than standard care (breathing exercise with Triflo, early ambulation, frequent position changes in bed) and treatment, which is the standard protocol of the Cardiovascular Surgery Service, by the clinic nurse and physician on the 1st, 2nd, 3rd and 4th days after surgery. Will not be implemented.

Olfactory mental imagery is the ability to detect an odor in the absence of any odor stimulus.

Participants will be asked to choose their 4 favorite fragrances from 20 different scents (such as rose, lavender scent) determined by the researcher and proven to have positive effects on mind-body therapy. The determined odors will be visualized by the researcher and picture cards measuring 15X12 cm (for example, a card with a rose picture for the rose smell, etc.) will be created. Participants will visualize the smell by looking at the picture cards, so they will be expected to make their breathing exercises more effective. Vagus breathing technique will be combined with olfactory mental imagery.

In this form; body temperature value will be evaluated.

In this form; respiratory rate will be evaluated.

In this form; pulse value will be evaluated

In this form; blood pressure value will be evaluated.

In this form; oxygen saturation value will be evaluated.

In this form; cerebral oxygen saturation value will be evaluated.

State Anxiety Inventory measures how the individual expresses himself in a momentary situation. The inventory consists of 20 items in total. In this inventory, each item is on a four-point Likert-type scale consisting of '(1) not at all', '(2) a little', '(3) a lot', '(4) completely' and 1. The total score obtained from the inventory varies between 20-80. High scores from the inventory indicate high anxiety.

The inventory consists of 5 subscales: general, cardiac, trunk, lower and upper extremity symptoms. The inventory is in Likert type and is evaluated between 0-4 as "Not at all", "Very little", "Moderate", "A lot", "Quite a lot". The score range to be taken from the inventory varies between 0-140. As scores increase, symptom severity also increases.