Funding Acknowledgements Type of funding sources: None. Background Dysfunction of the RV in patients with HFrEF is a prognostically unfavorable factor, which depends on the etiology, the duration of myocardial damage and the tactics of the treatment (Pharmacotherapy, Heart Surgery, CRTD, Heart Transplantation).  RV function in patients with HFrEF realized in the concept of continuous contraction of the muscle tape proposed by Torrent-Guasp, where systolic and diastolic interventricular interactions are carried out through the common IVS and implemented in the degree of dyssynchrony of ventricular contraction. 3DERV and STE (GLSRV, FWLS) may add the prognostic value of the more commonly used RV functional parameters as the sensitive echocardiographic predictors of worse prognosis in patients with HFrEF. Methods and Results A total of 79 patients with HFrEF (age, from 26 to 77 years; the clinical manifestations of HFrEF corresponded to NYHA III in 52 patients (71%), NYHA IV in 27 patients (29%); LV EF ≤ 35%). The etiology of HFrEF was mainly connected to patients with ischemic heart disease- 50 (63.2%), non-ischemic genesis 29 (36, 7%).The primary endpoint was a death in the follow-up period of up to 3 years in 33 patients (45,2%). An adverse outcomes and mortality during the first year was 17 (23,2%).  All patients were divided into subgroups 1 (n = 40) - survived during the 3-year, subgroups 2 (n = 33) - died during the 3-year follow-up period.  The presence of RV dysfunction in patients with HFrEF was independently associated with concomitant LV dysfunction but not with PASP (PASP/GLSLV, % (р=0,94), PASP/FWLS RV, % (р=0,97). RV contractility was realized through systolic and diastolic ventricular interactions, mediated through the shared IVS. This putative mechanism was supported by the independent association between septal S’ and S (HR - 1,12; 95%; Cl 0,99-1,26; p = 0,049), GLS BS LV, % и FWLS BS RV, % (HR - 0,90; 95%; Cl 0,79-1,00; p = 0,040). Kaplan–Meier plot, RVFWS > -15%, (χ2 – 4,438; р < 0,035), GLS >-10%, (χ2 – 3,796; р< 0,05), RVBSLS >-15%, (χ2 – 11,986; р = 0,0005), 3DERVEF <25% (χ2 – 7,518; р = 0,006), %CVCI <30% (χ2 – 7,85; р = 0,005), 3DE RAV > 100 ml (χ2 – 4,36; р = 0,036) were an independent predictors of worse prognosis in patients with HFrHF. The curves of the ROC analysis demonstrated a sensitivity of GLSRV - 80.7% as a prognostic factor of survival in patients with HrEF. At the same time, FWLS RV had a specificity (87.5%) compared to GLSRV, %, the longitudinal deformation of the isolated segments of the FWRV, FAC, %VCI collapse, ESDA/SA of RV, RAV. Conclusions  RV systolic dysfunction is a strong and independent predictor of in HFrEF. In case of HFrEF the longitudinal mechanism of RV reduction is more sensitive than others.  GLSRV, FWS RV, 3DRVEF, %VCI collapse has been proposed as a more accurate and sensitive tool to evaluate RV function in longitudinal displacement of patients with HFrEF. Abstract Figure. Kaplan–Meier plot GLS, 3DEEFRV, FWLS  Abstract Figure. ROC analysis

Background the volume and function of the right ventricle (RV) are the parameters that determine the echo predictive factors of mortality and reduce hospitalizations in patients with heart failure (HF) with reduced ejection fraction (HFrEF). In the concept of the mechanism of the contraction of the heart the global RV ejection fraction consist of combined longitudinal, radial and anteroposterior displacement of the RV walls. RV pump function realized by shortening of the longitudinal axis with the traction of the tricuspid annulus towards the apex; inward movement of the RV free wall; bulging of the interventricular septum into the RV and stretching the free wall over the septum. In case of HFpEF the longitudinal mechanism of RV reduction is more sensitive than others. Longitudinal strain of RV free wall (RVFWS) and 3DRVEF has been proposed as a more accurate and sensitive tool to evaluate RV function in longitudinal displacement of patients with HFpEF. Methods and Results—A total of 73 patients with HFpEF (age, from 26 to 77 years; the clinical manifestations of HFpEF corresponded to NYHA III in 52 patients (71%), NYHA IV in 21 patients (29%); LV EF ≤ 35%) with preserved TAPSE (≤15 mm) underwent RV function assessment using 4DETomTec, speckle-tracking TTE to measure peak RVFWS, GLS, 4DEEF. After a median follow-up period of 36 months, 61 (83%) patients reached the primary composite end point of all-cause death/Heart transplantation. Median RVFWS was −12.3% (interquartile range, −20.3% to −9.4%). Median RVGLS was −15.3% (interquartile range, −21.3% to −10.54%). Median RV4DEF was 31.6% (interquartile range, 21,1% to 36,2%). By Kaplan–Meier plot, RVFWS > -15%, (p < 0,02), GLS >-20%, (p < 0,04), 4DETomtecEF <30% (p < 0,0001) were an independent predictor of outcome in patients with HFpHF. Conclusions: In patients with HFpEF the fast and accurate quantification of RV free-wall strain and 4DTomtecEF provides incremental prognostic information and improved risk stratification.