Demographic and echocardiographic characteristics of the study group.

†significance of changes when comparing baseline and follow up measurements <0.05; 2D RV-Sl, two dimensional right ventricular longitudinal strain; ACEI, angiotensin converting enzyme inhibitors; AHI, apnea hypopnea index; ARBI, angiotensin receptor blocker; CAD, coronary artery disease; CHF, chronic heart failure; BMI, body mass index; e/e′, early/early′; ESS, Epworth sleepiness scale; HLP, hyperlipoproteinemia; IVSd, diastolic interventricular septum thickness; LVEF, left ventricular ejection fraction; LV/RV MPI, left ventricular/right ventricular myocardial performance index; MV e′/a, mitral velocity early′/atrial; ns, not statistically significant; ODI, oxygen desaturation index; SD, standard deviation; sPAP, systolic pulmonary artery pressure; SV, stroke volume; TAPSE, tricuspid annular plane systolic excursion; TDI TKS, tricuspid annular systolic tissue Doppler velocity.