Abstract
Early signs of right ventricular (RV) dysfunction were analyzed in patients with obstructive sleep apnoea syndrome (OSAS) by combining 2D Speckle Tracking (ST) and real-time 3D echo. Forthy-six OSAS patients and 30 age-and sex-matched healthy controls were enrolled. RV diameters, tricuspid annular plane systolic excursion (TAPSE) and estimated pulmonary arterial systolic pressure (PAPs) were assessed by standard echo, RV global longitudinal strain (GLS) by ST, RV end-diastolic and end-systolic volumes (EDV and ESV respectively) and RV ejection fraction (EF) by 3D echo. OSAS severity was assessed by the apnea/hypopnea index (AHI). The two groups were comparable for heart rate whereas body mass index (BMI) (p<0.0001) and systolic blood pressure (SBP) (p<0.005) were higher in OSAS. They showed larger 2D-derived RV basal transverse diameter (p<0.0001) and 3D EDV (p<0.01) in comparison with controls. RV GLS was lower in OSAS than in controls (-21.0 ± 5.1 vs. -25.9 ± 1.55%, p<0.0001). By dividing OSAS patients according to PAPs, 22 patients with PAPs > 25 mmHg had lower RV GLS (-18.9 ± 3.3% vs. -23±5.6%, p<0.005) and higher AHI (45.9 ± 26 vs 28.3 ± 20.3, p<0.05) than patients with PAPs < 25 mmHg. Only PAPs increase was independently associated with RV GLS reduction (β= 0.596, p<0.01) by multiple regressione analysis. Early reduction of RV GLS is detectable in OSAS patients when TAPSE and RV EF are still normal. Thi finding appears to be dependent on the severity of pulmonary arterial hypertension, independently on OSAS severity. The degree of PAPs should be used to stratify OSAS patients at higher risk for RV failure.
- Copyright ©ERS 2015
