Right Atrial Function and Right Ventricular Diastolic Function and Their Relation With Exercise Capacity in OSAS

Right ventricular (RV) diastolic function and right atrial (RA) function are poorly characterized in patients with obstructive sleep apnea syndrome (OSAS), but may influence exercise capacity. We aimed to evaluate RA function and RV diastolic function in OSAS and study their relationship with exercise capacity.

Fifty-three patients with OSAS and thirty age- and gender-matched controls prospectively underwent echocardiography and cardiopulmonary exercise testing to investigate RV diastolic function, RA function, and exercise capacity.

Altered RV diastolic function in patients with severe OSAS was indicated by the increased tricuspid valve E/e' ratio (TV E/e'), isovolumic relaxation time (IVRT), and by the reduced RV TDI e' velocity. The TV E/e' correlated modestly with peak VO₂ (r = -0.334, p < 0.01). Patients with severe OSAS exhibited impaired RA total emptying fraction, RA passive emptying fraction, and RA reservoir strain (RARS), with RARS being associated with peak oxygen uptake (VO₂) (r = 0.451, p < 0.01 for reservoir function).

Altered RA function and RV diastolic function in patients with OSAS are associated with impaired exercise capacity. The correlation of RA function and RV diastolic function with exercise capacity suggests that it may be important to evaluate RA function and RV diastolic function in this population.