A simple approach to mechanical modeling of single mitral valve chorda

Abstract

The mitral valve (MV) separates the left atrium (LA) from the left ventricle (LV) and controls the blood flow from the LA into the LV. It is composed of the valve annulus, the valve leaflets (anterior and posterior), the chordae tendineae and the papillary muscles. During diastole, the MV opens as a result of increased pressure in the LA as it fills with blood. Diastole ends with atrial contraction and the leaflets close thus preventing the backflow of the blood into the LA. Mitral valve prolapse is a condition in which the MV does not close smoothly but instead one or both leaflets bulge upward into the LA. This is mostly due to the rupture of the chordae tendineae that support the MV. In some cases, the prolapsed MV lets a small amount of blood flow backwards from the LV into the LA. This disorder is called mitral regurgitation (MR). If mild, MR may not cause problems, however, severe MR can lead to a life-threatening emergency. The severity of MR generally depends on the number and location of the ruptured chordae [1]. Consequently, the rupture of individual chorda may be the initial reason for violation of healthy functioning of the MV. Numerical simulation of the MV based on the patient specific data became common practice in scientific research and medical practice. Recently, the focus on mechanics of chordae is increasing, different finite element models of the MV structure have been built and tested [2, 3] to better understand the behavior of the chordae tendineae. However, such calculations are time consuming and geometrydependent, as the simulation of the MV function must be performed but the understanding of a single chorda is still insufficient. Therefore, the simplified approach to determine mechanical behavior of the chordae tendineae without the MV simulation is of major practical importance. In this report, evaluation of mechanical load of a single chorda is considered.