Vagus Nerve Stimulation for Autonomic Modulation After Coronary Artery Bypass Graft Surgery

The objective of this randomized clinical trial is to investigate whether transcutaneous auricular vagus nerve stimulation (taVNS) can improve the recovery of patients undergoing coronary artery bypass grafting (CABG) through autonomic modulation, while also evaluating the safety of the intervention. The main questions this study aims to answer are: * Does taVNS improve autonomic modulation, as assessed by heart rate variability, in patients undergoing CABG? * Does taVNS reduce the inflammatory response and pain intensity while improving quality of life and functional capacity during the postoperative period? * Is taVNS a safe and well-tolerated intervention during recovery after CABG? The researchers will compare taVNS with a control group (sham stimulation/placebo) to determine whether the intervention leads to better clinical and functional outcomes in patients undergoing coronary artery bypass grafting. Participants will: * Receive sessions of transcutaneous auricular vagus nerve stimulation (taVNS) or sham stimulation (placebo), according to the study randomization. * Undergo assessments of autonomic modulation using heart rate variability before and after the intervention. * Be evaluated for inflammatory markers, pain intensity, quality of life, and functional capacity at different time points during the postoperative period.

Inclusion Criteria: Patients aged ≥18 years who are undergoing coronary artery bypass grafting (CABG), are able to understand and comply with the study protocol, and provide written informed consent Exclusion Criteria: * History of severe cardiac arrhythmias or recent electrical instability, including permanent atrial fibrillation, tachyarrhythmias, or the presence of an implantable cardioverter-defibrillator (ICD). * Presence of a pacemaker or other implanted electronic devices. * Severe neurological or psychiatric disorders, such as epilepsy, schizophrenia, or recent stroke (within the past 6 months). * Active chronic inflammatory or autoimmune diseases that may interfere with inflammatory markers (e.g., systemic lupus erythematosus or rheumatoid arthritis). * Acute infection or fever at the time of screening. * History of ear surgery or ear injury that would preclude the application of transcutaneous auricular vagus nerve stimulation (taVNS). * Confirmed or suspected pregnancy (for female participants of childbearing potential).