Echocardiographic Information
Echocardiographic was carried out using 2D TEE (X8-2T probe, Philips echocardiography machine EPIQ -7, Philips Healthcare, Andover, MA, USA) to determine MR severity. MR was confirmed by color flow and Doppler indices according to the MR severity criteria. MR severity criteria are as follows: 1. Mild: Vena Contracta width (VCW) ≤ 0.3 cm, proximal isovelocity surface area (PISA) radius absent or ≤ 0.3 cm, Normal LV and LA size, Effective Regurgitant Orifice Area (EROA) < 0.2 cm (for primary MR), Regurgitant Volume (RVol) < 30 ml, Regurgitant Fraction (RF) < 30%. 2. Moderate: intermediate values and EROA 0.20-0.39 cm( for primary MR), RVol 30-59 ml, RF 30-49%. 3. Severe: Flail leaflet, VCW ≥ 0.7 cm, PISA radius ≥ 1.0 cm, EROA ≥ 0.4 cm, RVol ≥ 60 ml, RF ≥ 50% (8).
Then patients underwent 2D TTE (X8-2T probe, Philips echocardiography machine EPIQ -7, Philips Healthcare, Andover, MA, USA), and a comprehensive examination of the mitral valve and mitral regurgitation at standard imaging views was conducted. The demographic characteristics of patients, including sex and age, and the echocardiographic parameters of hemodynamic burden, including mitral valve velocity-time integral (VTI), left ventricular outlet (LVOT) diameter, LVOTVTI, mitral valve annulus (MVA) diameter, were acquired. The parameters investigating the hemodynamic burden of MR are listed below:
  1. MVVTI/LVOTVTI:\(\frac{\mathbf{Mitral\ valve\ velocity-time\ integral}\mathbf{\ }\mathbf{\ (MV\ VTI)}}{\mathbf{Left\ ventricle\ outlet\ velocity-time\ integral\ (LVOT\ VTI)}}\)MVVTI was measured with pulse Doppler at MV annulus in A4C view. LVOTVTI was measured with pulse Doppler at LVOT in A5C view.
  2. MVAVTI-i:\(\mathbf{\text{\ \ \ }}\frac{\mathbf{\text{mitral\ valve\ annulus\ diameter\ }}\mathbf{}\mathbf{\ \ Mitral\ valve\ velocity-time\ integral}}{\mathbf{\text{BSA}}}\)MVA was measured in A4C view just after the beginning of the mitral leaflet closing. i = indexed for body surface area (BSA).
  3. MVAVTI/LVOTDVTI:\(\frac{\mathbf{\text{Mitral\ valve\ annulus\ diameter\ }}\mathbf{}\mathbf{\text{\ MV\ VTI}}}{\mathbf{LVOT\ D*LVOT\ VTI}}\)LVOTD was measured at PLAX view in mid-systole.
  4. E velocity-LA area-i:\(\mathbf{\text{\ \ E\ velocity\ }}\mathbf{}\mathbf{\ left\ atrium\ (LA)\ area\ }\)/ BSA E velocity was measured at the mitral leaflet tip in diastole. LA area was measured in A4C view at its largest area. i = indexed for BSA.