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This study used cardiac magnetic resonance imaging to evaluate flow characteristics and ventricular hemodynamics for children with single right (hypoplastic left heart syndrome) and single left (hypoplastic right heart syndrome) systemic ventricle anatomy after Fontan palliation compared with normal biventricular controls. Twenty children with single ventricle anatomy (hypoplastic left heart syndrome, n = 10; hypoplastic right heart syndrome, n = 10) underwent standardized 4-dimensional flow cardiac magnetic resonance and were compared with age-matched controls (n = 10). End-diastolic volume was partitioned into 4 defined components of variable kinetic energy (direct flow, retained inflow, delayed ejection, and residual volume) and compared between groups. Further, volumetric and functional parameters as defined by cardiac magnetic resonance were evaluated. Children with hypoplastic left heart syndrome had significantly increased indexed end-diastolic and end-systolic volumes compared with both hypoplastic right heart syndrome and control groups. Flow component analysis demonstrated diastolic inefficiency in both hypoplastic left heart syndrome and hypoplastic right heart syndrome groups compared with controls as defined by decreased direct flow and increased residual volumes. Decreased direct flow correlated with decreased ejection fraction and increased end-diastolic and end-systolic volume indices. Increased residual volume correlated with decreased ejection fraction and increased end-systolic volume index. Fontan-palliated patients with single ventricle physiology (hypoplastic left heart syndrome and hypoplastic right heart syndrome) demonstrate altered and inefficient flow patterns in the systemic ventricle as defined by 4-dimensional flow cardiac magnetic resonance compared with normal biventricular controls. Decreased direct flow and increased residual volume indicate that diastolic ventricular dysfunction is prevalent after Fontan palliation. This study provides a foundation for future predictive modeling and cardiac magnetic resonance flow diagnostic studies in this high-risk patient population. Flow component analysis by 4D-flow CMR demonstrates inefficient diastolic inflow partitioning in patients with HLHS and HRHS compared with biventricular control patients as defined by decreased direct flow and increased residual volume. [Display omitted] [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine whether aortic biomechanical properties are abnormal in children with repaired truncus arteriosus (TA) and to concurrently evaluate left ventricular (LV) function post-repair utilizing a novel platform for regional ventricular function. Cardiac magnetic resonance (CMR) studies from 26 children (mean age: 15.6 ± 7.2 years) post-TA repair were compared with 20 normal controls (mean age: 14.7 ± 2.6 years). Parameters of aortic stiffness (pulse wave velocity and relative area change) were measured. Flow hemodynamic metrics (aortic regurgitant fraction, peak systolic flow, and peak systolic velocity) and LV function (volumetric data, ejection fraction, regional wall strain) were also compared. Ascending aortic pulse wave velocity was elevated and relative area change was decreased in TA patients compared with controls. Patients post-TA repair demonstrated elevated end diastolic and end systolic volumes in addition to decreased regional wall strain and increased mechanical dyssynchrony. LV functional changes were independent of aortic biomechanical properties. Children with repaired TA have increased ascending aortic stiffness and altered LV function as measured by CMR imaging. Longitudinal studies and advanced CMR assessments are warranted to better determine the long-term potential for late aortic complications and to optimize both the medical and surgical management of these patients after TA repair. [Display omitted] [ABSTRACT FROM AUTHOR]

Ross and Ross-Konno operations are associated with the inherent risk of residual ventricular septal dysfunction and injury to the conduction system. However, comprehensive biventricular functional outcomes on magnetic resonance imaging after Ross and Ross-Konno procedures are unknown. The purpose of this study was to evaluate and compare the degree of electrical and mechanical dyssynchrony using cardiac magnetic resonance imaging in patients late after Ross and Ross-Konno operations. Patients following Ross operation (n = 16), Ross-Konno operation (n = 13), and healthy controls (n = 12) underwent cardiac magnetic resonance imaging strain deformation analysis to quantify left ventricular (LV) intraventricular dyssynchrony and right ventricular (RV)–LV interventricular dyssynchrony. Mechanical dyssynchrony indices were correlated with the degree of electrical dyssynchrony as assessed by QRS duration, as well as with magnetic resonance imaging-derived biventricular and autograft regurgitation parameters. Patients in the Ross and Ross-Konno groups had reduced LV global longitudinal strain when compared with controls (both P values <.01). Both Ross (P <.05) and Ross-Konno (P <.01) groups demonstrated increased RV–LV interventricular dyssynchrony compared with controls. Patients in the Ross-Konno group also had increased septal LV intraventricular dyssynchrony when compared with control and Ross groups (both P values <.01). The global LV intramechanical dyssynchrony strongly correlated with QRS duration (R = 0.716; P <.001). There was no association between mechanical dyssynchrony and aortic regurgitation fraction. Long-term follow-up of patients who underwent Ross and Ross-Konno operations demonstrates reduced LV global longitudinal strain suggestive of chronically increased afterload independent of autograft function. Additionally, Ross-Konno operation is associated with impaired LV intraventricular mechanics and electrical dyssynchrony. [ABSTRACT FROM AUTHOR]

An abstract of the article "Comparative assessment of pediatric right ventricular volumes and function by MRI: right horizontal long axis versus short axis," by Brian D. Soriano and colleagues is presented.