Altered regional myocardial velocities by tissue phase mapping and feature tracking in pediatric patients with hypertrophic cardiomyopathy

Abstract

Background-Hypertrophic cardiomyopathy (HCM) is associated with heart failure, atrial fibrillation and sudden death. Reduced myocardial function has been reported in HCM despite normal left ventricular (LV) ejection fraction. Additionally, LV fibrosis is associated with elevated T1 and might be an outcome predictor.Objective-To systematically compare tissue phase mapping and feature tracking for assessing regional LV function in children and young adults with HCM and pediatric controls, and to evaluate structure-function relationships among myocardial velocities, LV wall thickness and myocardial T1.Materials and methods-Seventeen pediatric patients with HCM and 21 age-matched controls underwent cardiac MRI including standard cine imaging, tissue phase mapping (two-dimensional cine phase contrast with three-directional velocity encoding), and modified Look-Locker inversion Terms of use and reuse: academic research for non-commercial purposes, see here for full terms. http://www.springer.com/gb/openaccess/authors-rights/aam-terms-v1

Causes of Altered Ventricular Mechanics in Hypertrophic Cardiomyopathy—an In-Silico Study

“…Therefore, we showed that the effect of these two pathologies cancel out in our virtual HCM heart to obtain the same peak diastolic velocity as in the control case (Figure 10, right). If we would either further reduce the active force in the LV or less deviate from the control stiffness (or both), we would obtain reduced diastolic velocities in line with [10].…”

“…Altered Mechanics in HCM Patients Reported in the Literature In HCM patients, global strains and strain rates are reported to be significantly lower [1,11,12], while Ito et al [9] measured preserved (or even increased) circumferential shortening. Furthermore, altered myocardial velocities are detected in HCM patients compared to controls-global and segmental diastolic velocities are decreased and systolic longitudinal velocities were reduced in HCM [10]. In the left atria, a higher minimum volume and a lower peak atrial longitudinal strain was measured in HCM compared to controls [11].…”

“…Therefore, we confirm the suggestion of Villemain et al [5] that modified LV relaxation might result from increased myocardial stiffness. Furthermore, Li et al [10] measured reduced peak velocities during the systole in patients with HCM in the longitudinal direction (radial peak velocities were comparable). We observed a reduction of the velocities during the systolic period as well but for all directions (longitudinal, circumferential and radial).…”

“…Case 2 and Case 7), we observed an opposite effect when the stiffness was increased, the strain became more homogeneous. Velocity: Li et al [10] measured reduced global and segmental diastolic radial and longitudinal peak velocities in patients with HCM vs. controls. In contrast, we did not observe a reduction of any peak velocity during the diastolic period in our virtual HCM heart compared to the control heart.…”

“…Furthermore, MRI can quantify heart motion and function by cine imaging, which enables LV wall thickness calculation. Tissue phase mapping and feature tracking provide LV radial, circumferential and longitudinal myocardial velocity time courses, as well as global and segmental systolic and diastolic peak velocities [10]. The left atrial longitudinal strain is measured as well to inform HCM diagnosis [11].…”