Respiratory Alkalosis as a Therapeutic Target in Cardiac Rehabilitation for Dysautonomia: Mechanisms and Applications

Background: Dysautonomia is a group of autonomic nervous system disorders that often manifest as postural orthostatic tachycardia syndrome (POTS) or vasovagal syncope, producing orthostatic intolerance, syncope, and exercise intolerance. Respiratory alkalosis, characterized by decreased arterial CO₂ and elevated blood pH due to hyperventilation, significantly influences cerebral perfusion, baroreflex sensitivity, and autonomic balance. Objective: To analyze respiratory alkalosis as a therapeutic target within cardiac rehabilitation for patients with dysautonomia, highlighting underlying mechanisms and clinical applications. Methods: This narrative review synthesizes pathophysiological mechanisms linking respiratory alkalosis to dysautonomia and evaluates the role of ventilatory retraining, aerobic and resistance training, and cardiopulmonary exercise testing (CPET) as tools to modulate autonomic dysfunction. Results: Cardiac rehabilitation strategies integrating ventilatory control improve CO₂ homeostasis, reduce hyperventilation-induced hypocapnia, and enhance autonomic regulation. Concurrent aerobic-resistance training strengthens baroreflex sensitivity, stabilizes cardiovascular responses, and decreases symptom burden. CPET allows individualized monitoring of functional capacity, ventilatory efficiency, and autonomic recovery. Conclusion: Cardiac rehabilitation represents an effective and safe approach for patients with dysautonomia when respiratory alkalosis is addressed as a therapeutic target. Incorporating ventilatory control, guided breathing, and concurrent training into rehabilitation programs can reduce orthostatic intolerance, improve functional outcomes, and enhance quality of life.