STS E Book - Tricuspid Valve Flashcards
Describe the tricuspid valve, anatomically
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.
Is rheumatic heart disease more common in the developed or undeveloped portions of the world?
Undeveloped. Still an important cause of tricuspid regurgitation and stenosis.
How does connective tissue disorder cause tricuspid valvular incompetence?
Connective tissue disorders (eg Marfan) lead to myxomatous degeneration of TV leaflets, chordal elongation, prolapse, and therefore incompetence of the valve.
Infective endocarditis of the TV causing severe TR is most commonly associated with what?
IVDU. TV endocarditis in a non IVDU pt is rare. The exception is permanent pacemaker leads.
Why should surgical intervention for TV IE be performed with caution?
Pts tolerate TR well hemodynamically given the low pressure of the R heart. TV IE emboli to lungs are not as catastrophic as systemic emboli from L sided IE. IVDU pts have ongoing risks of reinfection, OD, and noncompliance.
How can carcinoid syndrome cause TR and TS?
R side heart involvement is common. White endocardial plaques may form on the TV leaflet surface, which can cause TR and TS, resulting from the inability of the leaflets to coapt.
