Mitral valve

The mitral valve consists of two leaflets, the anterior (A) and the posterior valve leaflet (P), which together have a surface area of 4-6cm. At the inner edges of the leaflets chordae tendinae are attached, which ensure that the leaflets did not prolapse back into the atria during systole. The chordae attach to two large papillary muscles, that are part of the muscular tissue of the left ventricle.

The mitral valve can be visualized in many views: PLAX, PSAXmv, AP4Ch, AP5Ch, AP2Ch, AP3Ch and subcostaal4Ch. A prolapse of the MV is best assessed on PLAX. However, mitral regurgitation should be assessed in all views. In case of major abnormalities of the mitral valve 3D TEE has additional value in assessing the anatomy and function.

Scallop partition of mitral valve

Quantification of mitral valve regurgitation

MR severity classes 𝜁	Mild	Moderate	Moderate	Severe
	Grade 1 or 1+	Grade 2 or 2+	Grade 3 or 3+	Grade 4 or 4+
Qualitative
Valve morphology	None or mild leaflet abnormality	Moderate leaflet abnormality	Moderate leaflet abnormality	Flail leaflet / large coaptation defect
	or minimal tenting	or moderate tenting	or moderate tenting	or severe tenting
Colour flow MR jet	Small, central	Intermediate	Intermediate	Very large central jet or eccentric jet adhering,
				swirling and reaching the posterior wall of the LA
	Usually <4cm²	Usually 4-6cm²	Usually 6-8cm²	Usually >8cm²
	<20% of LA	20-30% of LA	30-40% of LA	>50% of LA
Flow convergence zone 𝛼	No or small faint	Dense	Dense	Large throughout systole, dense, holosystolic
CW signal of MR jet	Parabolic	Partial or parabolic	Parabolic or triangular	Triangular
Semi quantitative
Vena contracta width (mm)	<3	3 to <5	5 to <7	≥7 (>8 for biplane) 𝛽
Pulmonary vein flow	Systolic dominance	Variable	Systolic blunting	Systolic pulmonary vein flow reversal 𝛾
MV inflow	A wave dominant 𝛽	Variable	E-wave dominant (E>1.2m/s) 𝜀	E-wave dominant (E>1.2m/s) 𝜀
VTI mitral / VTI LVOT	<1	Intermediate	>1.2 𝜀	>1.4 𝜀
Quantative
EROA (mm²)	<20	20-29	30-39	≥40
R Vol (mL)	<30	30-44	45-59	≥60
RF (%)	<30	30-39	40-49	≥50
Structural parameters
LV and LA size	Usually normal	Normal or dilated	Usually dilated	Usually dilated
PA pressure	Usually normal	Normal or elevated	Normal or elevated	Usually elevated
Grading severity mitral regurgitation

CW, continuous wave; EROA, effective regurgitant orifice area; LA, left atrium; LV left ventricle; MR, mitral regurgitation; PA pulmonary artery; RF, regurgitant fraction; R Vol regurgitant volume; VC, vena contracta.
𝛼 At Nyquist limit of 50-60 cm/s.
𝛽 For average between AP4Ch an AP2Ch.
𝛾 Unless other reasons, of systolic blunting (atrial fibrillation, elevated LA pressure).
𝛿 Usually after 50 years of age.
𝜀 In the absence of other causes of elevated LA pressure and of mitral stenosis.
𝜁 Different thresholds are used in secondary mitral regurgitation where an EROA >20mm² and regurgitant volume > 30mL identify a subset of patients at increased risk of cardiac events.

Parameter	Criteria
Qualitative
Valve morphology	Flail leaflet/ruptured pappilairy muscle/large coaptation defect
Colour flow regurgitant jet	Very large central jet or eccentric jet adhering, swirling and reaching the posterior wall of the LA
CW signal of regurgitant jet	Dense/triangular
Other	Large flow convergence zone *
Semiquantitative
Vena contracta width (mm)	≥7 (>8 for biplane) **
Upstream vein flow	Systolic pulmonary vein flow reversal
Inflow	E-wave dominant ≥1.5 m/s ***
Other	TVI mitral/TVI aortic >1.4
Quantative	Primary	Secundary ****
EROA (mm²)	≥40	≥20
Regugitant volume (mL/beat)	≥60	≥30
Enlargement of cardiac chamber/vessels	LV, LA

* At Nyquist limit of 50-60 cm/s.
** For average between AP4Ch an AP2Ch.
*** In the absence of other causes of elevated LA pressure and of mitral stenosis.
**** Different thresholds are used in secondary mitral regurgitation where an EROA >20mm² and regurgitant volume > 30mL identify a subset of patients at increased risk of cardiac events.

Severe MR because of prolaps

Annulus dilation	Degeneracy	Acquired valve deviation	Secundary
Atriumfibrillation	Malcaptation in mitral valve stenosis	Billowing	Rhythm disorders (LBBB-->diastolic MR)
LV dilation		Prolaps	SAM in HCM
LA dilation		Floppy valve
		Flail leaflet
		Chordal rupture
		Ruptured Papillary muscle

Ruptured mitral chordae tendineae assessed with 3D TEE

Quantification of mitral stenosis

Mild	Moderate	Severe
MVA (cm²)	> 1.5	1.5 - 1.0	< 1.0
PGmean (mmHg)	< 5	5 - 10	> 10
PHT (m/s)	< 90	90 - 150	> 150

Causes of mitral stenosis

Acquired	Tumor	Congenital
Degeneracy	Myxoma	Parachute valve
Rheumatic fever		Cor triatriatum sinistrum

European Heart Journal - Cardiovascular Imaging (2022) 23, e171–e232

J Am Soc Echocardiogr. 2009 Jan;22(1):1-23; quiz 101-2

Eur J Echocardiogr. 2010 May;11(4):307-32

European Heart Journal (2017) 00, 1-53