Abstract 10983: Complementary Relationship of Right Ventricular Contraction Between Longitudinal and Radial Directions
Background: Unlike to left ventricular contraction, the mechanism of right ventricular contraction has been unclear because of its complex geometry. Right ventricular cavity changes during systole mainly by longitudinal and radial contractions. A detail process of right ventricular contraction has not been studied yet. An aim of this study is to analyze the relationship between longitudinal and radial contractions of right ventricle in healthy children.
Methods: We studied 300 consecutive healthy children and adolescents aged ranged from newborn baby to 22.2 years old (a mean age of 4.5 years old). In apical 4-chamber view, we measured tricuspid annular plane systolic excursion (TAPSE) by M-mode echocardiography as longitudinal right ventricular contraction. In short axis view, we got right ventricular radial contraction measuring the distance between right ventricular anterior wall and interventricular septum both in end-systole (RVESd) and end-diastole (RVEDd) by M-mode echocardiography (Figure). Right ventricular radial contraction (%RVF) was calculated as “100×(RVEDd-RVESd)/RVEDd”. Right ventricular stroke volume (RVSV) was obtained by pulse Doppler echocardiography as an index of right ventricular performance.
Results: There is an excellent good correlation between RVSV and TAPSE (r = 0.89, p < 0.0001). With aging, TAPSE is increased, but %RVF is decreased. However, there was an inverse and good correlation between TASPE and %RVF (%RVF = -3.6TAPSE +70.2, r = -0.73, p < 0.0001)(Figure).
Conclusions: Right ventricular longitudinal and radial contractions are complimentary relation. RVSV is generated mainly by longitudinal contraction. But in neonate, RVSV is supported not only by longitudinal contraction but also by radial contraction. Such complementary relationship of right ventricle is regarded as important for understanding of right ventricular function.
- © 2012 by American Heart Association, Inc.