Left-ventricular cavity dimensions in children with normal and dilated hearts

Abstract

Studies were carried out to find how left-ventricular length and length/diameter ratio relate to body size and degree of dilation. By use of M-mode and two-dimensional echocardiography, diastolic cavity long axis (Led), diastolic cavity diameter (Ded), systolic cavity long axis (Les), systolic cavity diameter (Des), fractional L shortening (SFL), and fractional D shortening (SFD) were measured in children, adolescents, and young adults between two and 23 years of age, with body-surface area (BSA) between 0.5 and 2.1 m2 and with a variety of volume loads and SFD values. In normal subjects, Led/Ded was about 1.9. Regardless of age and pathology (in this age range), Led correlated consistently with BSA (Led = 3.9 + 3.2 BSA), indicating that the long axis changes rather little with pathological dilation. A plot of Led/Ded vs BSA/D2ed (in m2/cm2) formed a straight-line relation: Led/Ded = 0.77 + 16.4 BSA/D2ed. Similar relations were found for end-systolic dimensions. End-systolic L/D ratio exceeded end-diastolic L/D ratio to a degree that depended on both end-diastolic L/D ratio and SFD:Les/Des = Led/Ded + (0.22 + 2.67 Led/Ded)(SFD)2. Relations like these may be useful in the interpretation of echocardiographic images. The results suggest that left-ventricular L/D ratio may be influenced by myocardial anisotropy (dominance of hoop over meridional fiber orientation tending to promote prolate shape especially during systole) and external factors that antagonize extension of the long axis.

Investigation of a novel intracardiac flow parameter using blood speckle imaging

“…To determine the theoretical angle at each point in the vortex flow field, an ellipse with an aspect ratio of 1.7 was used to define a Region Of Interest (ROI) and as the basis for calculation. This aspect ratio aligns with the ratio of long-to short-axis length observed for the pediatric left ventricle [13]. The slope of the tangent at a point [x1,y1] on an ellipse with no angle of rotation is given by: where where the inverse tangent of the slope gives the theoretical angle (θT), or direction, from -90 to 90 O .…”

Mathematical modeling of cardiac function to evaluate clinical cases in adults and children

“…The systolic elastance values in the child cardiovascular system model were selected, considering the data given in [32]. The ventricular long axis length is taken from [33] for the simulated age and body surface area. The zero pressure volumes of the heart chambers ( V 0 ) were decreased in the child cardiovascular system model [34].…”

Recommendations for Quantification Methods during the Performance of a Pediatric Echocardiogram: A Report from the Pediatric Measurements Writing Group of the American Society of Echocardiography Pediatric and Congenital Heart Disease Council

“…Consequentemente, o plano de eixo curto é a abordagem recomendada porque permite escolher o diâmetro com a melhor interface entre o endocárdio e o sangue, uma vantagem definitiva quando se está lidando com a trabeculação do VE. Adicionalmente, são disponíveis dados normais de pediatria para as medidas do Modo M no eixo curto 15,91,92 .…”