Quantification of the relative contribution of the different right ventricular wall motion components to right ventricular ejection fraction: the ReVISION method

Abstract

Three major mechanisms contribute to right ventricular (RV) pump function: (i) shortening of the longitudinal axis with traction of the tricuspid annulus towards the apex; (ii) inward movement of the RV free wall; (iii) bulging of the interventricular septum into the RV and stretching the free wall over the septum. The relative contribution of the aforementioned mechanisms to RV pump function may change in different pathological conditions.Our aim was to develop a custom method to separately assess the extent of longitudinal, radial and anteroposterior displacement of the RV walls and to quantify their relative contribution to global RV ejection fraction using 3D data sets obtained by echocardiography.Accordingly, we decomposed the movement of the exported RV beutel wall in a vertex based manner. The volumes of the beutels accounting for the RV wall motion in only one direction (either longitudinal, radial, or anteroposterior) were calculated at each time frame using the signed tetrahedron method. Then, the relative contribution of the RV wall motion along the three different directions to global RV ejection fraction was calculated either as the ratio of the given direction’s ejection fraction to global ejection fraction and as the frame-by-frame RV volume change (∆V/∆t) along the three motion directions.The ReVISION (Right VentrIcular Separate wall motIon quantificatiON) method may contribute to a better understanding of the pathophysiology of RV mechanical adaptations to different loading conditions and diseases.Electronic supplementary materialThe online version of this article (doi:10.1186/s12947-017-0100-0) contains supplementary material, which is available to authorized users.

Dominance of free wall radial motion in global right ventricular function of heart transplant recipients

“…It has been shown that 3D echocardiography‐derived ejection fraction is a useful marker of functional status after HTX . Moreover, further analysis of the 3D models enables to separately quantify the different wall motion directions and evaluate the relative contribution of each component . Using this approach, our results confirmed the dominance of radial wall motion in HTX patients.…”

“…There are three major mechanisms which contribute to RV pump function: (i) longitudinal shortening by traction of the tricuspid annular plane towards the apex; (ii) the inward (radial) motion of the RV free wall referred as the bellows effect; and (iii) the bulging of the interventricular septum during the left ventricular contraction along with stretching the free wall over the septum . The relative significance of the aforementioned mechanisms may be different in certain cardiovascular conditions.…”

“…The volumes of the models accounting for only one direction were calculated at each time frame using the signed tetrahedron method. By the decomposition of the 3D model's motion along the three orthogonal, anatomically relevant axes, volume loss attributable to either longitudinal, radial or anteroposterior wall motions could be separately quantified . Thus, longitudinal (LEF), radial (REF), and anteroposterior (AEF) ejection fraction and their ratio to TEF (LEF/TEF, REF/TEF, AEF/TEF, respectively) could be expressed as a measure of the relative contribution of the given wall motion direction.…”

Kajakos és kenus élsportolók bal és jobb kamrai analízise 3D echokardiográfia segítségével

“…fúj-tató) komponenseinek relatív arányában (26). Ez utóbbi mozgásirány jelentőségét a hagyományos echokardiográfi ás paraméterek gyakorlatilag nem mérik (27), noha teoretikusan akár segítséget jelenthet az edzés indukálta jobbkamra-diszfunkció kimutatásában is.…”

Respite for 2-Dimensional Right Ventricular Imaging?

“…10 Measurement of end-systolic RV free wall length relates to the longitudinal contraction of the right ventricle. 11 However, RV contractility does not only depend on the traction of the tricuspid annulus toward the apex. Bulging of the interventricular septum into the RV and radial displacement of the lateral free wall are important contributors to RV pump function.…”