Anatomy
The tricuspid valve ensures that there is no backflow from the right ventricle to the right atrium during systole. The tricuspid valve, as its Latin name suggests, consists of three leaflets: the septal (S), the anterior (A) and posterior (P) leaflets, of which the anterior leaflet is the largest. The tricuspid valve is distinguished not only by the number of valve leaflets as compared to mitral valve, but also by its method of attachment. The mitral valve chordae attach to only two papillary muscle heads where the chordae of tricuspid attach to much more muscle heads and also directly into the interventricular septum. The valve is located slightly more towards the apex as compared to the mitral valve.
Regurgitation
Quantification of tricuspid regurgitation
| Parameter | Mild | Moderate | Severe |
|---|---|---|---|
| RV/RA/IVC | normal | normal/dilated | dilated |
| Hepatic vein flow | syst. dominant | syst. decrease | syst. flow reversal |
| Vena contracta (mm) | <7 | >7 | |
| PISA (cm²) | < 0.6 | 0.6 - 0.9 | > 0.9 |
| Density CW signal | licht | dens | dens |
| Contour CW signal | parabolic | variable | triangular |
| TR jet / RA area* (%) | < 20 | 20 - 34 | > 35 |
| * The size of the color-doppler surface in right atrium is only a rough impression. | |||
Echocardiographic criteria for the definition of severe tricuspid valve regurgitation: an integrative approuch.
Parameter Criteria
Qualitative
Valve morphology Abnormal/flail/large coaptation defect
Colour flow regurgitant jet Very large central jet or eccentric wall impinging jet *
CW signal of regurgitant jet Dense/triangular with early peaking (peak <2 m/s in massive TR)
Semiquantitative
Vena contracta width (mm) ≥ 7 *
Upstream vein flow Systolic hepatic vein flow reversal
Inflow E-wave dominant ≥ 1 m/s **
PISA radius (mm) > 9 ***
Quantative
EROA (mm²) ≥ 40
Regugitant volume (mL/beat) ≥ 45
Enlargement of cardiac chamber/vessels RV, RA, IVC
* At Nyquist limit of 50-60 cm/s.
** In the absence of other causes of elevated LA pressure
*** Baseline Nyquist limit shift of 28 cm/s.
Outcome-based cut-off values for the quantitative parameters used to grade tricuspid regurgitation severity by Dopplerechocardiography.
Variable Low risk Intermediate risk High risk
VC (mm) <3 3 - 6 >6
EROA (cm²) <0.15 0.15 - 0.30 >0.30
RegVol (ml) <15 15 - 30 >30
RegFR (%) <25 25 - 45 >45
EROA, effective regurgitant orifice area; RegFr, regurgitant fraction; RegVol, regurgitant volume; VCavg, vena contracta width.
Eur Heart J Cardiovasc Imaging (2021) 22, 155-165
Proposed expansion of the ‘Severe’ grade
Variable Mild Moderate Severe Massive Torrential
VC (mm) <3 3 - 6.9 7 - 13 14 - 20 ≥21
EROA (cm²) <0.20 0.20 - 0.39 0.40 - 0.59 0.60 - 0.79 ≥80
3D VCA or quantitative EROAa (cm²)* 0.75 - 0.94 0.95 - 1.14 ≥1.15
VC, vena contracta; EROA, effective regurgitant orifice area; 3D VCA, three-dimensional vena contracta area.
*3D VCA and quantitative Doppler EROA cut-offs may be larger than PISA EROA.
Eur Heart J Cardiovasc Imaging (2017) 18, 1342–1343
Causes of tricuspid regurgitation
Functional TR Secundary TR
Disorders of the right ventricle: RV infarction, dilated cardiomyopathy Ebstein anomaly
Secondary to pulmonary hypertension, for example: cor pulmonale, pulmonary embolism, or primary. Infective Endocarditis
Mitral stenosis or mitral regurgitation Trauma
Left-right shunt, such as an atrial septal defect or a ventricular septal defect Rheumatic fever
Eisenmenger syndrome (rare) Carcinoid
Pulmonary stenosis Papillary muscle disorders
Hyperthyroidism Connective tissue diseases such as Marfan Syndrome.
Non-infectious endocarditis, such as SLE or rheumatoid arthritis
Damage from the electrode of a pacemaker or ICD
Stenosis
Tricuspid valve stenosis is usually caused by rheumatic fever which mostly occurs during childhood. The rarely reported second causes of tricuspid valve stenosis include tumour obstruction, carcinoid disease and obstructed tricuspid valve prosthesis.
Quantification of tricuspid stenosis
| Parameter | Mild | Moderate | Severe |
|---|---|---|---|
| TVA (cm²) | < 1 | ||
| PHT (ms) | > 190 | ||
| PGmean (mmHg) | > 5 | ||
| VTI (cm) | > 60 |
References
Eur J Echocardiogr. 2009 Jan;10(1):1-25 Eur J Echocardiogr. 2010 May;11(4):307-32 European Heart Journal (2017) 00, 1?53 European Heart Journal - Cardiovascular Imaging (2017) 18, 1342–1343 European Heart Journal - Cardiovascular Imaging (2021) 22, 155–165