Tricuspid regurgitation assessment
From Echocardiography in ICU
Etiology of tricuspid regurgitation
The presence of mild tricuspid regurgitation (TR) is physiologic in 65-100% of the population. More than mild regurgitation is abnormal and is suspicious for tricuspid valve disease:
- Functional tricuspid regurgitation
Functional TR is the most frequent etiology. It is secondary to poor tricuspid leaflets coaptation due to dilatation of tricuspid annulus and right chambers.
- Organic tricuspid regurgitation
Organic tricuspid regurgitation can be due to
-rheumatic heart disease
-endocarditis (IV drugs)
-congenital heart disease (Ebstein)
The patient's history and the two-dimensional assessment of the valve will be useful in these cases.
- Iatrogenic tricuspid regurgitation
The presence of pace-maker or intra-cardiac defibrillator, as well as repeated right ventricle biopsies (transplanted patients) lead to tricuspid trauma and TR.
Assessment of tricuspid regurgitation
Mechanisms of regurgitation: patient's history and two-dimensional echocardiography
The observation of the tricuspid valve in two-dimension images, from parasternal long axis right chamber view and apical 4 chamber view, will give some indications on the mechanism of regurgitation:-rheumatic heart disease: the valve will be thickened and restricted. It is very important to look for associated tricuspid stenosis and other valves involvement. On this apical 4 chamber view, you can see the thickening of the tricuspid valve, and the moderate tricuspid regurgitation (blue-yellow color flow)
-congenital heart disease: in Ebstein anomaly, the septal leaflet of the tricuspid valve will be apically displaced, with lack of coaptation with other leaflets. On this apical 4 chamber view, you can see the apical displacement of the septal tricuspid leaflet, which is 2cm more apical than the anterior mitral leaflet.
Color-Doppler imaging: severity of regurgitation
Tricuspid regurgitation will appear as a systolic jet going from RV to RA(blue jet in all views).Parasternal long axis, right chamber view. There is moderate TR (blue-yellow systolic jet)
Apical 4 chamber view. There is moderate excentric TR directed toward the inter-atrial septum:
Color Doppler imaging is used to quantify tricuspid regurgitation in the same manner than for mitral regurgitation.
Please go to the images library for examples of tricuspid regurgitation
Tricuspid regurgitation for calculation of right ventricle systolic pressure
With continuous Doppler across the tricuspid valve, guided by color Doppler, you can measure the systolic pressure gradient between RV and RA, using Bernouilli law. RA pressure is estimated with the diameter and respiratory variations of the IVC. The sum of RA pressure and gradient of pressure between RV and RA gives the RV pressure.
For more details, please read the chapter calculation of right ventricle pressure in the hemodynamics section.