Height Versus Body Surface Area to Normalize Cardiovascular Measurements in Children Using the Pediatric Heart Network Echocardiographic Z-Score Database

Impact of Obesity on Ventriculo-Arterial Interaction in Patients After Coarctation of Aorta repair

Survival of patients after repair of coarctation of Aorta (CoA) has improved significantly over the decades, but patients have decreased life expectancy as compared to the general population. This has been attributed to increased hypertension, cerebrovascular disease, and coronary artery disease. There has also been an increasing concern of overweight and obesity in patients with adult congenital heart disease. While there have been studies looking at the impact of long-term hypertension on myocardial performance and outcomes in this population, this study aims to assess the impact of obesity in these patients on their myocardial performance. Ventriculo-arterial coupling is used as a measure of myocardial performance which reflects the interaction between cardiac contractility and arterial elastance. Patients after CoA repair are known to have hypertension affecting the arterial elastance. Obesity affects cardiac contractility as well. This study demonstrated that in a group of young patients after CoA repair, body mass index (BMI) has a relationship with left ventricular (LV) contractility and myocardial performance. This relationship was independent of blood pressure. BMI itself was not seen to affect the determinants of diastolic function in this study, suggesting that LV contractility may be affected before one can notice a change in the diastolic function secondary to BMI.

Left Ventricular Diastolic Function in Children with Atrial Septal Defects Improves After Closure by Means of Increased Hydraulic Force

Hydraulic force aids diastolic filling of the left ventricle (LV) by facilitating basal movement of the atrioventricular plane. The short-axis atrioventricular area difference (AVAD) determines direction and magnitude of this force. Patients with atrial septal defect (ASD) have reduced LV filling due to the left-to-right shunt across the atrial septum and thus potentially altered hydraulic force. The aims were therefore to use cardiac magnetic resonance images to assess whether AVAD and thus the hydraulic force differ in children with ASD compared to healthy children, and if it improves after ASD closure. Twenty-two children with ASD underwent cardiac magnetic resonance before ASD closure. Of these 22 children, 17 of them repeated their examination also after ASD closure. Twelve controls were included. Left atrial and ventricular areas were delineated in short-axis images, and AVAD was defined as the largest ventricular area minus the largest atrial area at each time frame and normalized to body height (AVADi). At end diastole AVADi was positive in all participants, suggesting a force acting towards the atrium assisting the diastolic movement of the atrioventricular plane; however, lower in children both before (6.3 cm2/m [5.2-8.0]; p < 0.0001) and after ASD closure (8.7 cm2/m [6.6-8.5]; p = 0.0003) compared to controls (12.2 cm2/m [11.3-13.9]). Left ventricular diastolic function improves after ASD closure in children by means of improved hydraulic force assessed by AVAD. Although AVADi improved after ASD closure, it was still lower than in controls, indicating diastolic abnormality even after ASD closure. In patients where AVADi is low, ASD closure may help avoid diastolic function deterioration and improve outcome. This could likely be important also in patients with small shunt volumes, especially if they are younger, who currently do not undergo ASD closure. Changes in clinical routine may be considered pending larger outcome studies.

Atrioventricular Area Difference Aids Diastolic Filling in Patients with Repaired Tetralogy of Fallot

A hydraulic force aids diastolic filling of the left ventricle (LV) and is proportional to the difference in short-axis area between the left ventricle and atrium; the atrioventricular area difference (AVAD). Patients with repaired Tetralogy of Fallot (rToF) and pulmonary regurgitation (PR) have reduced LV filling which could lead to a negative AVAD and a hydraulic force impeding diastolic filling. The aim was to assess AVAD and to determine whether the hydraulic force aids or impedes diastolic filling in patients with rToF and PR, compared to controls. Twelve children with rToF (11.5 [9-13] years), 12 pediatric controls (10.5 [9-13] years), 12 adults with rToF (21.5 [19-27] years) and 12 adult controls (24 [21-29] years) were retrospectively included. Cine short-axis images were acquired using cardiac magnetic resonance imaging. Atrioventricular area difference was calculated as the largest left ventricular short-axis area minus the largest left atrial short-axis area at beginning of diastole and end diastole and indexed to height (AVADi). Children and adults with rToF and PR had higher AVADi (0.3 cm2/m [- 1.3 to 0.8] and - 0.6 [- 1.5 to - 0.2]) at beginning of diastole compared to controls (- 2.7 cm2/m [- 4.9 to - 1.7], p = 0.015) and - 3.3 cm2/m [- 3.8 to - 2.8], p = 0.017). At end diastole AVADi did not differ between patients and controls. Children and adults with rToF and pulmonary regurgitation have an atrioventricular area difference that do not differ from controls and thus a net hydraulic force that contributes to left ventricular diastolic filling, despite a small underfilled left ventricle due to pulmonary regurgitation.

Relationship of Left Ventricular Mass to Lean Body Mass in the Obese Pediatric Population

Our primary aim was to investigate the relationship between LVM and anthropometric measures including lean body mass (LBM) in obese pediatric subjects compared to normal weight controls. A retrospective chart review identified subjects 2-18 years old who were normotensive and had normal echocardiograms between 1995 and 2020 at Boston Children's Hospital. LVM was calculated with the 5/6 area length rule from 2D echocardiograms. LBM was calculated with equations derived from dual-energy X-ray absorptiometry. Of the 2217 subjects who met inclusion criteria, 203 were obese and 2014 had normal weight. The median age was 11.9 (2.0-18.9); 46% were female. The median LVM was 94.5 g (59.3-134.3) in obese subjects vs. 78.0 g (51.5-107.7) in controls. The median LBM was 37.2 kg (18.9-50.6) in obese subjects vs. 30.5 kg (17.6-40.8) in controls. In control and obese subjects, LBM had the strongest correlation to LVM (R2 0.86, P < 0.001) and (R2 0.87, P < 0.001), respectively. There was at most a modest correlation between tissue Doppler velocity z-scores and LV mass, and the largest was Septal E' z-score in obese subjects (r = - 0.31, P = 0.006). In this cohort, LBM was found to have the strongest relationship to LVM in obese subjects. The largest correlation between tissue Doppler velocity z-scores and LV mass was Septal E' z-score. Future studies will evaluate which measurements are more closely aligned with clinical outcomes in obese children.

Computed tomography for aortic assessment in children

Because the aorta is the major vessel of the body, basic knowledge of aortic pathology is essential to the pediatric imager. This review divides aortic pathology into anatomical (e.g., congenital abnormalities) and acquired (e.g., vasculitis, trauma) entities, providing a brief description of pathology, technical considerations in CT acquisition and processing, and some pearls and pitfalls of interpretation. The objective of this paper is to familiarize general pediatric imagers with imaging features of common as well as high-impact aortic pathology on CT and prepare them for acquisition and reporting.