Chordae tendineae explained

Chordae tendineae
Latin:chordae tendineae cordis

The chordae tendineae (: chorda tendinea) or tendinous cords, colloquially known as the heart strings, are inelastic cords of fibrous connective tissue that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart.[1]

Structure

The chordae tendineae connect the atrioventricular valves (tricuspid and mitral), to the papillary muscles within the ventricles. Multiple chordae tendineae attach to each leaflet or cusp of the valves. Chordae tendineae contain elastin in a delicate structure notably at their periphery.[2]

Tendon of Todaro

The tendon of Todaro is a continuation of the Eustachian valve of the inferior vena cava and the valve of the coronary sinus. Along with the opening of the coronary sinus and the septal cusp of the tricuspid valve, Koch's triangle is made up. The apex of Koch's triangle is the location of the atrioventricular node.[3]

Function

During atrial systole, blood flows from the atria to the ventricles down the pressure gradient. Chordae tendineae are relaxed because the atrioventricular valves are forced open.[4]

When the ventricles of the heart contract in ventricular systole, the increased blood pressures in both chambers push the AV valves to close simultaneously, preventing the backflow of blood into the atria. Since the blood pressure in the atria is much lower than that in the ventricles, the flaps attempt to evert to the low pressure regions. The chordae tendineae prevent this prolapse by becoming tense, which pulls on the flaps, holding them in a closed position.[4]

Clinical significance

Ruptured chordae tendineae

Valvular heart disease can lead to ruptured chordae tendineae. This can cause severe mitral insufficiency.

Parachute mitral valve

Parachute mitral valve occurs when all the chordae tendineae of the mitral valve attach to a single papillary muscle.[5] This causes mitral valve stenosis at an early age. It is a rare congenital heart defect. Although it often causes mitral insufficiency, it may not present any symptoms.

See also

Notes and References

  1. Web site: Hacking . Craig . Chordae tendineae Radiology Reference Article Radiopaedia.org . Radiopaedia.
  2. Green . EM . Mansfield . JC . Bell . JS . Winlove . CP . The structure and micromechanics of elastic tissue. . Interface Focus . 2014-04-06 . 4 . 2 . 20130058 . 10.1098/rsfs.2013.0058 . 24748954. 3982448 .
  3. McGuire . Mark A. . Johnson . David C. . Robotin . Monica . Richards . David A. . Uther . John B. . Ross . David L. . 1992-09-15 . Dimensions of the triangle of Koch in humans . The American Journal of Cardiology . en . 70 . 7 . 829–830 . 10.1016/0002-9149(92)90574-I . 1519544 . 0002-9149.
  4. 10.1161/01.RES.26.6.689 . 5422929 . Mechanism of Function of the Mitral Valve Leaflets, Chordae Tendineae and Left Ventricular Papillary Muscles in Dogs . Circulation Research . 26 . 6 . 689–96 . 1970 . Karas . S. . Elkins . R. C. . free .
  5. Web site: Llewelyn . Rhys . Parachute mitral valve Radiology Reference Article Radiopaedia.org . Radiopaedia.