Cardiac MRI evaluation of aortic biophysical properties in paediatric Turner syndrome.

Background: Aortopathy in Turner syndrome is associated with aortic dilation, and the risk of dissection is increased when the aortic size index is ≥ 2-2.5 cm/m. We evaluated the aortic biophysical properties in paediatric Turner syndrome using cardiac MRI to determine their relationship to aortic size index.

Adherence to clinical practice guidelines for pulmonary valve intervention after tetralogy of Fallot repair: A nationwide cohort study.

Objectives: To determine guideline adherence pertaining to pulmonary valve replacement (PVR) referral after tetralogy of Fallot (TOF) repair.

Methods: Children and adults with cardiovascular magnetic resonance imaging scans and at least moderate pulmonary regurgitation were prospectively enrolled in the Comprehensive Outcomes Registry Late After TOF Repair (CORRELATE). Individuals with previous PVR were excluded.

Regional Elevation of Liver T1 in Fontan Patients.

Background: Fontan-associated liver disease (FALD) is characterized by hepatic congestion and progressive hepatic fibrosis in patients with the Fontan operation. This condition is generally clinically silent until late, necessitating techniques for early detection. Liver T1 mapping has been used to screen for FALD, but without consideration of regional variations in T1 values.

Patient-Reported Outcomes After Tetralogy of Fallot Repair.

Background: Comprehensive assessment of tetralogy of Fallot (TOF) outcomes extends beyond morbidity and mortality to incorporate patient-reported outcomes (PROs), including quality of life (QOL) and health status (HS).

Objectives: This study explored PROs in adolescents and adults with TOF and delineated variables associated with PROs.

Methods: This was a cross-sectional observational study within a larger prospective registry of adolescents and adults with repaired TOF and moderate or greater pulmonary regurgitation from North America, Europe, and Asia.

Implementation of Virtual Fontan Heart Camps During a Pandemic.

Background: Children with a Fontan operation represent a unique form of congenital heart disease (CHD) that requires multiple cardiac surgeries and procedures with an uncertain long-term outcome. Given the rarity of the types of CHD that require this procedure, many children with a Fontan do not know any others like them.

Methods: With the cancelation of medically supervised heart camps due to the COVID-19 pandemic, we have organized several physician-led virtual day camps for children with a Fontan operation to connect with others in their province and across Canada.

T1 mapping of the myocardium and liver in the single ventricle population.

Background: Fontan associated liver disease (FALD) is an increasingly recognized complication of the single ventricle circulation characterized by hepatic venous congestion leading to hepatic fibrosis. Within the Fontan myocardium, fibrotic myocardial remodeling may occur and lead to ventricular dysfunction. Magnetic resonance imaging (MRI) T1 mapping can characterize both myocardial and liver properties.

Cardiac MRI-Derived Myocardial Deformation Parameters Correlate with Pulmonary Valve Replacement Indications in Repaired Tetralogy of Fallot.

Right ventricular (RV) volumetric cardiac magnetic resonance (CMR) criteria serve as indicators for pulmonary valve replacement (PVR) in repaired tetralogy of Fallot (rTOF). Myocardial deformation and tricuspid valve displacement parameters may be more sensitive measures of RV dysfunction. This study's aim was to describe rTOF RV deformation and tricuspid displacement patterns using novel CMR semi-automated software and determine associations with standard CMR measures.

Right Ventricular Remodeling in Hypoplastic Left Heart Syndrome is Minimally Impacted by Cardiopulmonary Bypass: A Comparison of Norwood vs. Hybrid.

Right ventricular (RV) remodeling in hypoplastic left heart syndrome (HLHS) begins prenatally and continues through staged palliations. However, it is unclear if the most marked observed remodeling post-Norwood is secondary to cardiopulmonary bypass (CPB) exposure or if it is an adaptation intrinsic to the systemic RV. This study aims to determine the impact of CPB on RV remodeling in HLHS.

Tilt-table Echocardiography Unmasks Early Diastolic Dysfunction in Patients With Hemoglobinopathies.

Individuals with hemoglobinopathy (sickle cell anemia and thalassemia major) are at risk for cardiac complications such as heart failure and cardiomyopathy. Diastolic dysfunction is known to precede systolic dysfunction in many cardiac diseases. This study sought to determine whether changes in left atrial (LA) function during manipulation of cardiac preload by tilt-table echocardiography can unmask subclinical diastolic dysfunction in pediatric patients with hemoglobinopathies.

Reduced Right Ventricular Fractional Area Change, Strain, and Strain Rate before Bidirectional Cavopulmonary Anastomosis is Associated with Medium-Term Mortality for Children with Hypoplastic Left Heart Syndrome.

Background: Ventricular dysfunction is associated with increased morbidity and mortality in children with hypoplastic left heart syndrome. The aim of this study was to assess the diagnostic performance of conventional and speckle-tracking echocardiographic measures of right ventricular (RV) function before bidirectional cavopulmonary anastomosis palliation in predicting death or need for heart transplantation (HTx).

Methods: RV fractional area change (RVFAC) and longitudinal and circumferential strain and strain rate (SR) were measured in 64 prospectively recruited patients with hypoplastic left heart syndrome from echocardiograms obtained before bidirectional cavopulmonary anastomosis surgery.

Strain Rate in Children and Young Piglets Mirrors Changes in Contractility and Demonstrates a Force-Frequency Relationship.

Background: In adult humans and pig models, strain rate (SR) correlates strongly with invasive measures of contractility but does not demonstrate a force-frequency relationship, which is a fundamental behavior of myocardial contraction. Given the considerable maturational changes of the myocardium from fetal stages to adulthood, extrapolation of adult findings to the young heart may not be appropriate. We sought to evaluate the SR response of the immature heart to increased heart rate (HR) and inotropic stimulation.

Impaired Single Right Ventricular Function Compared to Single Left Ventricles during the Early Stages of Palliation: A Longitudinal Study.

Background: Single right ventricles (SRV) are postulated to be disadvantaged compared with single left ventricles (SLV). We compared the evolution of SRV versus SLV function during infancy using conventional measures and speckle-tracking echocardiography (STE). We hypothesized that the SRV is mechanically disadvantaged during early infancy.

Stress perfusion magnetic resonance imaging to detect coronary artery lesions in children.

Background: Stress perfusion cardiovascular magnetic resonance (CMR) is used widely in adult ischemic heart disease, but data in children is limited. We sought to evaluate feasibility, accuracy and prognostic value of stress CMR in children with suspected coronary artery disease (CAD).

Methods: Stress CMR was reviewed from two pediatric centers over 5 years using a standard pharmacologic protocol.

Cardiac Magnetic Resonance Imaging in Pediatric Turner Syndrome.

Objective: To compare the detection of cardiac lesions with the use of cardiac magnetic resonance imaging (CMR) and conventional echocardiography in children with Turner syndrome.

Study Design: Twenty-four girls with Turner syndrome, 8-18 years of age, were recruited through the Pediatric Endocrinology Program. Participants underwent CMR and echocardiography within a 2-year period, and discrepancies between the results of each modality were identified.

Impaired Left Ventricular Reserve in Childhood Cancer Survivors Treated With Anthracycline Therapy.

Background: Childhood cancer survivors show evidence of diffuse myocardial fibrosis that is related to exercise capacity. The mechanism of reduced exercise tolerance in anthracycline cardiotoxicity remains unclear. We explored the determinants of exercise intolerance by evaluating left ventricular (LV) distensibility and functional reserve.

Rationale and design of the Canadian Outcomes Registry Late After Tetralogy of Fallot Repair: the CORRELATE study.

Background: Chronic hemodynamically relevant pulmonary regurgitation (PR) resulting in important right ventricular dilation and ventricular dysfunction is commonly seen after tetralogy of Fallot (TOF) repair. Late adverse clinical outcomes, including exercise intolerance, arrhythmias, heart failure and/or death accelerate in the third decade of life and are cause for considerable concern. Timing of pulmonary valve replacement (PVR) to address chronic PR is controversial, particularly in asymptomatic individuals, and effect of PVR on clinical measures has not been determined.

Increased common atrioventricular valve tenting is a risk factor for progression to severe regurgitation in patients with a single ventricle with unbalanced atrioventricular septal defect.

Objective: Significant atrioventricular valve regurgitation (AVVR) increases mortality in patients with unbalanced atrioventricular septal defects (uAVSDs) and a single ventricle. We tested the hypothesis that abnormal leaflet tethering is associated with progressive AVVR in patients with a single ventricle with uAVSD.

Methods: We retrospectively reviewed the initial presentation and prebidirectional cavopulmonary anastamosis echocardiograms of 46 consecutive patients with uAVSD with single ventricle palliation.

Insights into the evolution of myocardial dysfunction in the functionally single right ventricle between staged palliations using speckle-tracking echocardiography.

Background: The long-term prognosis of hypoplastic left heart syndrome is limited by progressive right ventricular dysfunction. The aim of this study was to determine the trends in single right ventricular systolic function between staged palliative surgeries using speckle-tracking and conventional echocardiography.

Methods: There were 76 patients with functionally single right ventricles at the (1) pre-Norwood (n = 26), (2) pre-bidirectional cavopulmonary anastomosis (BCPA; n = 19), (3) pre-Fontan (n = 16), and (4) post-Fontan (n = 15) stages, compared with 30 controls of similar ages.

Which cardiovascular magnetic resonance planes and sequences provide accurate measurements of branch pulmonary artery size in children with right ventricular outflow tract obstruction?

Children with right ventricular outflow tract obstructive (RVOTO) lesions require precise quantification of pulmonary artery (PA) size for proper management of branch PA stenosis. We aimed to determine which cardiovascular magnetic resonance (CMR) sequences and planes correlated best with cardiac catheterization and surgical measurements of branch PA size. Fifty-five children with RVOTO lesions and biventricular circulation underwent CMR prior to; either cardiac catheterization (n = 30) or surgery (n = 25) within a 6 month time frame.

Diffuse myocardial fibrosis by T1-mapping in children with subclinical anthracycline cardiotoxicity: relationship to exercise capacity, cumulative dose and remodeling.

Background: The late cardiotoxic effects of anthracycline chemotherapy influence morbidity and mortality in the growing population of childhood cancer survivors. Even with lower anthracycline doses, evidence of adverse cardiac remodeling and reduced exercise capacity exist. We aim to examine the relationship between cardiac structure, function and cardiovascular magnetic resonance (CMR) tissue characteristics with chemotherapy dose and exercise capacity in childhood cancer survivors.

Newer imaging modalities in the assessment of heart function in single ventricle hearts.

The limitations of geometry assumptions in 2-dimensional echocardiographic assessment of the single ventricle (SV) have been overcome by recent advances in 3-D echocardiography. Improved reproducibility for measuring ventricular volumes and ejection fraction using 3-D echocardiography makes it ideally suited for serial monitoring of SV systolic function and should be considered in routine echocardiography imaging protocols for SV. The moderate correlation of Doppler derived E/e' ratio with invasive ventricular end diastolic pressure in SV, suggests it might be useful in the assessment of SV diastolic function.

The assessment of atrial function in single ventricle hearts from birth to Fontan: a speckle-tracking study by using strain and strain rate.

Background: Single ventricle (SV) exercise performance is impaired and limited by reduced ventricular preload reserve. The atrium modulates ventricular filling, and enhancement of atrial compliance can increase cardiac performance. We aimed to study atrial mechanics in SV hearts across staged surgical palliation compared with healthy children by using novel speckle-tracking echocardiography techniques.

Single right ventricles have impaired systolic and diastolic function compared to those of left ventricular morphology.

Background: Differences in single right ventricle (SRV) and single left ventricles (SLV) function are poorly described, although myocardial dysfunction is an important risk factor for morbidity and mortality. The aims of this study were to compare function between patients with SRVs and those with SLVs using newer echocardiographic techniques and to determine differences across staged palliation.

Methods: In this cross-sectional study comparing 30 patients with SRVs and 30 with SLVs of similar ages (2.

Optimization of myocardial nulling in pediatric cardiac MRI.

Background: Current protocols to determine optimal nulling time in late enhancement imaging using adult techniques may not apply to children.

Objective: To determine the optimal nulling time in anesthetised children, with the hypothesis that this occurs earlier than in adults.

Materials And Methods: Sedated cardiac MRI was performed in 12 children (median age: 12 months, range: 1-60 months).