Aim : In this study , according to the diagnosed left ventricular diastolic dysfunction (LVDD) grades, we aimed to determine the correlation of the 2D speckle tracking echocardiography (2DSTE) derived left atrial functional parameters and echocardiographic right ventricular (RV) systolic functions and pulmonary vascular resistance (PVR) estimates in reduced ejection fraction heart failure patients (HFrEF). Methods : Dilated cardiomyopathy patients with an EF lower than 40% included. Echocardiographic examinations including PVR calculations and the 2DSTE performed ; LASr: left atrial reservoir strain , LAScd: left atrial conduit strain, LASct: left atrial contraction strain were calculated. LVDD grading was performed according to guidelines. Results: The mean EF was 28.8 ± 6.0 %. The estimated PVR was strongly correlated with LASr, LAScd and LASct (p<0,0001 for each parameter) . All of the LA strain parameters were in decreasing trend along with the increased LVDD grades. The LASct were lower in Grade III when compared with the Grade II LVDD (p<0.01) . Conclusion: The decrease of LA contraction function in Grade 3 diastolic dysfunction is evident and it may be associated with the extent of LA remodelling in these patients. PVR estimates well correlates with the LA strain parameters. Future studies may evaluate the value of estimated PVR for grading of LVDD.