Association between right ventricular strain and subclinical left ventricular dysfunction in obstructive sleep apnea-hypopnea syndrome.

OBJECTIVE

Using two-dimensional speckle-tracking echocardiography (2D-STE), this study analyzed biventricular strain changes in obstructive sleep apnea-hypopnea syndrome (OSAHS) and explored whether right ventricular (RV) dysfunction statistically mediates OSAHS-related left ventricular (LV) impairment.

METHODS

We enrolled 212 OSAHS patients and 52 controls, categorized by apnea-hypopnea index (AHI) into control (n = 52), mild-to-moderate (n = 80), and severe (n = 132) groups. We assessed 2D-STE-derived RV global longitudinal strain (RVGLS), RV free wall strain (RVFWS), and LV global longitudinal strain (LVGLS). Analyses included correlations, regressions, ROC curves, and mediation models.

RESULTS

RVGLS and RVFWS progressively became less negative with increasing OSAHS severity (P < 0.001), whereas LVGLS was significantly impaired only in severe OSAHS (P < 0.001). AHI correlated positively with RVGLS (r = 0.605), RVFWS (r = 0.583), and LVGLS (r = 0.302). RV strains showed good diagnostic value for severe OSAHS. Mediation analysis confirmed that RVGLS (β = 0.018, 95% CI: 0.007-0.029) and RVFWS (β = 0.013, 95% CI: 0.004-0.024) served as significant statistical mediators, which is statistically consistent with a mediating role in the AHI-LVGLS association.

CONCLUSION

Subclinical biventricular dysfunction occurs in OSAHS despite preserved LV ejection fraction. RV impairment is more sensitive to OSAHS severity than LV impairment and statistically mediates the AHI-LVGLS relationship. Routine 2D-STE RV strain assessment may facilitate early high-risk patient identification.