Tricuspid valve

The tricuspid valve, as well as the mitral valve, consists of a complex of anatomical formations, including a fibrous ring, valves, tendon chords, papillary muscles and adjacent areas of the right atrium and ventricle. Usually the tricuspid valve has three leaves, sometimes some are split. Distinguish septal (septal), front and rear, and commissures are called, respectively, front-parting, front and rear.

The fibrous ring that forms the tricuspid valve contains more elastic fibers relative to the fibrous mitral valve ring. The site adjacent to the septal region is the continuation of the membrane part of the interventricular septum. Near this region pass the pathways of the heart. The rest is more loose and contains muscle fibers. The dimensions of the fibrous ring are more pronounced in the area of its adherence to the right fibrous triangle and become thinner as they move away from this triangle. The outer part of the fibrous ring adjacent to the anterior and posterior leaves changes in shape and size (by 19-40%) due to the contraction and relaxation of the myocardium during the cardiac cycle.

In the leaflets that form the tricuspid valve, the base, overlap zone (body) and the clamping zone also separate. Valves valves (from 2 to 6) are supported by tendon chords and papillary muscles. The main one is the anterior one, not laid on the anterior wall of the right ventricle. Together with the supraventricular ridge, the septal trabeculae ("moderator strand") and the parietal wall of the right ventricle, the anterior part divides the ventricular cavity into the supply and outlet sections. The posterior papillary muscle is smaller. Small papillary muscles may be on the interventricular septum, sometimes the chords extend directly from the ventricular wall. The most common is 3-4 muscles, sometimes up to 7-10.

The tricuspid valve, like the mitral valve, has chords that are divided into chords of the 1st, 2nd and 3rd orders. The chords of the septum begin from the heads of small papillary muscles on the interventricular septum. To the front chords from the anterior papillary muscle are attached, and the tendon chords of the posterior wing depart from the group of posterior papillary muscles of the trabecular part of the septum. In the area of the anterior-septal commissure, the valves are supported by chords that run from the muscle of Lancisi. The functional significance of chords attached to different departments is not the same. Crossing the chords of the leaf base does not violate the closing function of the valve. Crossing the chords of the overlapping zone of one leaf does not cause regurgitation, two or more valves - leads to valvular insufficiency. Damage to the marginal chords of even one leaf leads to a disruption in the closure function of the formation, such as the tricuspid valve.

The relationship between the conductive system and the elements that form the tricuspid valve is important from a surgical point of view. In particular, the bundle of the Hyis runs parallel to the line of attachment of the septum of the tricuspid valve, and then through the right fibrous triangle and the fibrous ring in the region of the anterior-septum commissure (danger zone) is guided along the lower edge of the membranous septum. The depth of the bundle of the bundle in the area of the barrier is 1-2 mm. With myocardial hypertrophy of the right ventricle (with heart defects) and rheumatic damage to the formation such as the tricuspid valve, the bundle of Hyis can be located at a depth of 2-4 mm. In addition, the right coronary artery passes fairly close to the anterior segments of the fibrous ring (2-4 mm), especially in the lateral commissure.