             0.000   0.00 (0.00--0.00)   0.00 (0.00--0.00)   0.000   0.00 (0.00--0.00)   0.00 (0.00--0.00)   0.000  TDI = tissue Doppler imaging, LV = left ventricle, RV = right ventricle, IVS = interventricular septum, PDA = patent ductus arteriosus, VTI = velocity time integral, LA/Ao = left atrial to aortic root ratio, BP = blood pressure, HR = heart rate, SVC = superior vena cava, EF = ejection fraction, FS = fractional shortening, SV = stroke volume, CO = cardiac output, CI = cardiac index, MV = mitral valve, E = peaks of early diastolic flow velocities, A = peaks of late diastolic flow velocities, E′ = peak annular velocities during early diastole, A′ = peak annular velocities during late diastole, S′ = peak annular velocities during systole, MPI = myocardial performance index, MCO = mitral valve closure to opening time, ET = ejection time, EDV = end diastolic volume, TV = tricuspid valve, TCO = tricuspid valve closure to opening time.  