| Structural parameters | |
|---|---|
| LA and LV Size | |
| Utility/Advantages: | Enlargement sensitive for chronic significant MR, important for outcomes. Normal size virtually excludes significant chronic MR. |
| Limitations: | Enlargement seen in other conditions. May be normal in acute significant MR |
| MV leaflet/support apparatus | |
| Utility/Advantages: | Flail valve and ruptured papillary muscle specific for significant MR |
| Limitations: | Other anormalities do not imply significant MR |
| Doppler parameters | |
| Jet area–Color Flow | |
| Utility/Advantages: | Simple, quick screen for mild or severe central MR; evaluates spatial orientation of jet |
| Limitations: | Subject to technical, hemodynamic variation; significantly underestimates severity in wall-impinging jets |
| Vena contracta width | |
| Utility/Advantages: | Simple, quantitative, good at identifying mild or severe MR |
| Limitations: | Not useful for multiple MR jets; intermediate values require confirmation. Small values; thus small error leads to large % error |
| PISA method | |
| Utility/Advantages: | Quantitative; Presence of flow convergence at Nyquist limit of 50–60 cm/s alerts to significant MR. Provides both, lesion severity (EROA) and volume overload (R Vol) |
| Limitations: | Less accurate in eccentric jets; not valid in multiple jets. provides peak flow and maximal EROA. |
| Flow quantitation–PW | |
| Utility/Advantages: | Quantitative, valid in multiple jets and eccentric jets. Provides both lesion severity (EROA, RF) and volume overload (R Vol) |
| Limitations: | Measurement of flow at MV annulus less reliable in calcific MV and/or annulus. Not valid with concomitant significant AR unless pulmonic site is used. |
| Jet profile–CW | |
| Utility/Advantages: | Simple, readily available |
| Limitations: | Qualitative; complementary data. |
| Peak mitral E velocity | |
| Utility/Advantages: | Simple, readily available, A-wave dominance excludes severe MR |
| Limitations: | Influenced by LA pressure, LV relaxation, MV area, and atrial fibrillation. Complementary data only, does not quantify MR severity |
| Pulmonary vein flow | |
| Utility/Advantages: | Simple, Systolic flow reversal is specific for severe MR |
| Limitations: | Influenced by LA pressure, atrial fibrillation. Not accurate if MR jet directed into the sampled vein |
CW, Continuous wave Doppler; EROA, effective regurgitant orifice area; LA, left atrium; PISA, proximal isovelocity surface area; LV, left ventricle; PW, pulsed wave Doppler; MV, mitral valve; MR, mitral regurgitation; R Vol, regurgitant volume.