Left Ventricular Rotation and Twist Assessed by Four‐Dimensional Speckle Tracking Echocardiography in Healthy Subjects and Pathological Remodeling: a Single Center Experience

Abstract

Identification and inclusion of apical-cap is relevant for twist assessment and can be carried out efficiently by 3D-STE. The inclusion of the true apex in the calculation significantly affects the analysis of twist both in normal individuals and patients with different myocardial diseases.

Left Ventricular Twist and Torsion

“…The thicker sector of 3D-STE allows for capturing as many speckles as possible and tracking them in all directions while overcoming through-plane motion that usually affects 2D-STE, which allows for measurements at lower frame rates. Results are, however, variable because of the limited spatiotemporal resolution of current 3D-echocardiography systems, 8 which decreases its ability in capturing events occurring in fast phases of the cardiac cycle, such as isovolumic contraction and isovolumic relaxation.…”

Correlations between echocardiographic aortic elastic properties and left ventricular rotation and twist – Insights from the three‐dimensional speckle‐tracking echocardiographic MAGYAR‐Healthy Study

“…However, the results obtained by the echocardiographic method used correlate well with those from invasive methods (Stefanadis et al ., ). Temporal resolution of 3D acquisition for speckle‐tracking analysis is low as compared to 2D echocardiography, which can affect the good tracking of speckles. Moreover, to achieve rapid frame or volume rates, the 3D sector angle must be reduced in most of cases which could aggrevate the evaluation of the LV (Urbano‐Moral et al ., ; Lilli et al ., ). This was a single‐centre experience and limited by a relatively small number of healthy volunteers. The study would have been statistically stronger, if larger number of subjects had been evaluated. Due to the facts, that little is known regarding to the factors affecting rotational mechanics of the heart, heterogeneity of population and etiologies (age, gender etc.)…”

In silico investigation of the short QT syndrome, using human ventricle models incorporating electromechanical coupling

“…Thus, the total potential energy functional Π for the mechanics problem is formulated as: $\Pi (u,p)={\Pi }_{\text{int}}(u,p)+{\Pi }_{\text{ext}}(u)$ where Π int ( u, p ) is the internal potential energy or total strain energy of the body and Π ext ( u ) is the external potential energy or potential energy of the external loading of the body. With the axes of the geometry aligned to the underlying tissue microstructure (Seemann et al, 2006; Legrice et al, 1997), the second Piola-Kirchhoff stress tensor S , obtained from the directional derivative of Equation 6 in the direction of an arbitrary virtual displacement and which relates a stress to a strain measure (Holzapfel, 2000; Bonet and Wood, 2008) is defined as: $S=\frac{1}{2}\left(\frac{\partial W}{\partial E_{\text{MN}}}+\frac{\partial W}{\partial E_{\text{NM}}}\right)-p{C}_{\text{MN}}^{-1}+S_{\text{ActiveTension}}$ where W is a strain energy function that defines the constitutive behavior of the material, E is the Green-Lagrange strain tensor that quantifies the length changes in a material fiber and angles between fiber pairs in a deformed solid, C is the Right-Cauchy green strain tensor, p is a Lagrange multiplier (referred to as the hydrostatic pressure in the literature) used to enforce incompressibility of the cardiac tissue, S ActiveTension is a stress tensor incorporating active tension from the electromechanics cell model and enables the reproduction of the three physiological movements of the ventricular wall: longitudinal shortening, wall thickening and rotational twisting (MacGowan et al, 1997; Lorenz et al, 2000; Tseng et al, 2000; Bogaert and Rademakers, 2001; Cheng et al, 2008; Coppola and Omens, 2008; Lilli et al, 2013). …”