Is jet length used to assess Mitral Regurgitation (MR)?

From the Guidelines

Jet length is not a reliable standalone measure for assessing mitral regurgitation (MR) severity, and its use is not recommended for quantifying MR severity. When evaluating the severity of mitral regurgitation using color Doppler echocardiography, several parameters are examined, including jet area, vena contracta width, regurgitant volume, effective regurgitant orifice area, and pulmonary vein flow patterns 1. The length of the regurgitant jet into the left atrium can be influenced by technical factors like transducer position, instrument settings, and hemodynamic conditions such as blood pressure.

Key Parameters for MR Assessment

• Jet area
• Vena contracta width
• Regurgitant volume
• Effective regurgitant orifice area
• Pulmonary vein flow patterns

According to the European Association of Cardiovascular Imaging and the Acute Cardiovascular Care Association, the recommended approaches to quantify mitral regurgitation include measurement of the vena contracta and the PISA method 1. A vena contracta width ≥ 0.7 mm or an effective regurgitant orifice area ≥ 40 mm2 indicates severe mitral regurgitation.

Recommendations for MR Severity Assessment

• Use multiple parameters to assess MR severity
• Measure vena contracta width and use the PISA method when feasible
• Consider the clinical context and hemodynamic conditions when interpreting echocardiographic findings 1

From the Research

Assessment of Mitral Regurgitation

• The assessment of mitral regurgitation (MR) severity is a complex process that involves evaluating several echocardiographic parameters, including proximal isovelocity surface area (PISA)-derived regurgitant volume, PISA-derived effective regurgitant orifice area, vena contracta, color Doppler jet/left atrial area, left atrial volume index, left ventricular end-diastolic volume index, peak E wave, and the presence of pulmonary vein systolic reversal 2.
• Color Doppler jet area and jet length are also used to assess MR severity, with the jet area to left atrial area ratio being a good predictor of MR severity 3.
• The use of jet length to assess MR severity is supported by a study that found that jet length was a predictor of clinical outcome in patients with secondary MR 4.
• However, another study found that color Doppler jet area can overestimate regurgitant volume when multiple jets are present, which can lead to incorrect assessment of MR severity 5.

Parameters Used to Assess MR Severity

• The following parameters are used to assess MR severity:
  • Proximal isovelocity surface area (PISA)-derived regurgitant volume
  • PISA-derived effective regurgitant orifice area
  • Vena contracta
  • Color Doppler jet/left atrial area
  • Left atrial volume index
  • Left ventricular end-diastolic volume index
  • Peak E wave
  • Presence of pulmonary vein systolic reversal
  • Jet length 2, 3, 4

Limitations of MR Assessment

• The assessment of MR severity can be challenging due to the discordance between different echocardiographic parameters 2.
• The use of color Doppler jet area and jet length to assess MR severity can be limited by the presence of multiple jets, which can lead to overestimation of regurgitant volume 5.
• The integrated eyeballing approach, which takes into account multiple parameters, including jet length, can perform better than color Doppler quantification of the MR jet area and length in predicting clinical outcomes 4.