Impact of Cardiac Coherence on Anxiety in Patients Operated on for a Peritoneal Carcinosis

This study is testing whether a breathing technique called cardiac coherence (slow, rhythmic breathing that synchronizes heartbeat and breath) can reduce anxiety in patients about to undergo major surgery to remove cancer that has spread to the lining of the abdomen (peritoneal carcinosis). The technique is simple, drug-free, and can be done in minutes. **You may be eligible if...** - You are over 18 years old - You have peritoneal carcinosis and are waiting for cytoreductive surgery (surgery to remove as much cancer as possible from the abdomen) - You are experiencing meaningful anxiety (score above 3 on an anxiety visual scale) - You speak French well enough to understand instructions - You are hospitalized the day before your surgery **You may NOT be eligible if...** - You already regularly practice cardiac coherence breathing - You have a diagnosed psychiatric disorder (such as psychosis or bipolar disorder) - You do not understand French - You are not affiliated with the French social security system Talk to your doctor to see if this trial is right for you.