Objective Inspiratory efforts against an occluded airway lead to a swift drop in intrathoracic pressure with a subsequent increase in afterload leading to increased left atrial (LA) stiffness and impaired compliance over time. Therefore the object of the study was to evaluate LA ejection force (LAEF), LA contractile peak strain and basic diastolic left ventricular parameters in patients with obstructive sleep apnoea (OSA) before and after continuous positive airway pressure therapy (CPAP), using two-dimensional speckle-tracking Echocardiography and conventional Echocardiography.

Methods Newly diagnosed patients with OSA were selected. Eleven patients with a respiratory disturbance index (RDI) greater than 10 were enrolled to receive CPAP therapy with follow-up assessment after 12 weeks. Echocardiography including deformation imaging was performed at baseline and after 12 weeks of CPAP therapy. LAEF was calculated by the formula by Manning et al, LAEF=0.5 × 1.06 × MOA × (peak A velocity).²

Results LA peak contractile strain and left atrial ejection force reduced over the 12 weeks (p<0.05) and (p<0.001) respectively. Left ventricular filling pressure (E/E’) also reduced (p<0.05) along with an increase in the surrogate for early diastolic untwisting tissue velocity (Ea.) (p<0.05).

Conclusions LA mechanics can improve as early as 12 weeks into CPAP as assessed by conventional Echocardiography and deformation imaging.