Altered Ventilatory Mechanics and Recovery in Long COVID (LC) Patients with Dysfunctional Breathing (DB).

Introduction:. This study investigates the distinct ventilatory pattern and recovery kinetics in Long COVID (LC) patients with co-existing Dysfunctional Breathing (DB) compared to healthy controls.

Methods: We compared respiratory parameters in LC and DB patients against LC patients without DB during the post-exercise recovery period after Cardiopulmonary Exercise Testing (CPET).

Results: LC/DB patients exhibited a significantly higher RR and lower Vt compared to controls. They also demonstrated lower VO2/RR in the 3rd minute of recovery. Critically, while VE and PETCO2 not differ between groups, LC/DB patients displayed poor recovery, sustaining pronounced tachypnoea (≈30 breaths /minute) up to the 3rd min  of the recovery phase. 

Conclusion: The findings suggest that LC/DB patients employ a rapid, shallow breathing strategy. This inefficient ventilatory pattern—characterized by low Vt and, particularly, the sustained post-exertional tachypnoea—indicates a severe disruption in autonomous respiratory control (Erratic Breathing) and a potential contributor to their persistent exertional dyspnea and fatigue.