Tricuspid Valve Flashcards
What are the causes of tricuspid regurgitation (TR)?
- Normal leaflet motion - annular dilation (secondary to pulmonary hypertension, right ventricular failure, mitral valve disease), infective endocarditis.
- Excessive leaflet motion - myxomatous degeneration.
- Restricted leaflet motion - rheumatic fever, Ebstein’s anomaly.
How is tricuspid stenosis quantified by echocardiography?
- According to the AHA guidelines, the main criteria is a tricuspid valve area (TVA) <1cm2 for severe TS.
- The TVA can be calculated by the continuity equation or planimetry.
- The mean tricuspid diastolic pressure gradient can also be used to quantify tricuspid stenosis.
- Significant stenosis of the tricuspid valve may be present with a mean gradient of 3 to 5 mm Hg and an end-diastolic gradient of 1 to 3 mm Hg.
What are the indications for tricuspid valve surgery in the absence of mitral valve disease?
- Class IIa - severe TR in symptomatic patients.
- Other considerations include:
- Tricuspid valve annulus size (>40mm) on ECHO
- intraoperative diameter greater than 70 mm (
maximal stretched orifice from the anteroseptal to anteroposterior commissures. )
- Right ventricular function and size
- Pulmonary hypertension (>50mmHg at rest, 60mmHg on exercise),
- Right atrial size and the presence of atrial fibrillation.
Quantification of tricuspid regurgitation based on regurgitant jet?
Semiquantitative evaluation of the severity of tricuspid regurgitation is based on the degree of penetration of the regurgitant jet into the right atrium.
- A jet that penetrates 2 cm into the right atrium indicates mild regurgitation.
- A jet that penetrates 3 to 5 cm is considered moderate regurgitation;
- If it is accompanied by systolic flow reversal of hepatic or caval veins, it is considered severe regurgitation.
Quantification of tricuspid regurgitation based on PISA -proximal isovelocity surface area.
- A radius of 1 to 4 mm indicates mild regurgitation;
- 5 to 8 mm indicates moderate regurgitation; and
- Greater than 9 mm indicates severe regurgitation.
Describe the tricuspid valve
R sided b/w R atrium and R ventricle. Leaflets anterior (largest), posterior (multiple scallops), septal (smallest). Chordae tendinae, 2 papillary muscles (anterior and posterior), fibrous tricuspid annulus, R atrial and ventricular myocardium.
Why is the tricuspid septal leaflet spared from annular dilation?
The septal leaflet is the smallest and fixed.
The base of which tricuspid leaflet is used as a reference for sizing of tricuspid annuloplasty rings?
septal leaflet
Where do the chordae tendinae come from and go to in the tricuspid valve?
anterior papillary muscle supplies chordae to the anterior and posterior
posterior papillary muscle supplies chordae to the septal and posterior
Where are tricuspid accessory chordal attachments found and why are they important?
R ventricular free wall or the moderator band. May play a role in tricuspid regurgitation.
Why is the TV complex intimately associated with the conduction system?
Because the AV node lies within the triangle of Koch - tendon of Todaro, the septal leaflet of the TV, and the origin of the coronary sinus.
Pathology related to the TV is dependent on what three things?
Leaflet morphology, loading conditions of the heart, and degree of RV dysfunction.
How does RV dysfunction lead to tricuspid regurgitation?
RV dysfunction leads to chordal tethering, then loss of leaflet apposition, and thus TR. When the RV dilates, the tricuspid annulus enlarges (anterior/posterior dimension d/t septal leaflet fixed nature) causing failure of leaflet coaptation and TR.
Compare the TV to the mitral and aortic valves. What is the result of this difference?
The TV consists of a complex 3-dimensional structure, which is not symmetrical (unlike the other valves). As a result, loading conditions may change the orientation of the annular dimension significantly - eg during systole, there is a near 20% reduction in the size of the TA.
What is the most common L side pathology associated with TR?
mitral valve pathology - pulmonary HTN will develop as a result of L side overload from MR, the TA will dilate, and the leaflets will fail to coapt causing TR.
Less common etiologies - Eisenmenger syndrome and primary pulmonary HTN.
