All data are saved and stored digitally for off-line postoperative analysis. The Ejection Fraction (EF) is determined using the Simpson's method. Patients with EF lower than 50% do not continue for the study. The global longitudinal peak systolic strain (GLPSS) is used to assess LV mechanics in the longitudinal axis of LV motion. The TAPSE index is employed for the assessment of the right ventricular function. LV filling pressures in diastole is estimated by the E/Em ratio (E=peak velocity flow in early diastole, Em=the average of peak velocities in early diastole of lateral and septal mitral annulus). In addition, LV dimensions and wall thickness are measured either in short or long parasternal axis view. Stroke volume of the LV is assessed by VTILVOT (pulsed-wave Doppler of velocity time integral in the LV outflow tract).