Haki Jashari

Normal ranges of left ventricular strain in children: a meta-analysis

AimsThe definition of normal values of two-dimensional speckle-tracking echocardiography derived left ventricular (LV) deformation parameters, is of critical importance for the routine application of this modality in children. The objectives of this study were to perform a meta-analysis of normal ranges for longitudinal, circumferential and radial strain/strain rate values and to identify confounders that may contribute to differences in reported measures.Methods and ResultsA systematic search was conducted. Studies describing normal healthy subjects and observational studies that used control groups as a comparison were included. Data were combined using a random-effect model. Effects of demographic, clinical and equipment variables were assessed through meta-regression. The search identified 1,192 subjects form 28 articles. Longitudinal strain (LS) normal mean values varied from -12.9 to -26.5 (mean, -20.5; 95% CI, -20.0 to -21.0). Normal mean values of circumferential strain (CS) varied from -10.5 to -27.0 (mean, -22.06; 95% CI, -21.5 to -22.5). Radial strain (RS) normal mean values varied from 24.9 to 62.1 (mean, 45.4; 95% CI, 43.0 to 47.8). Meta-regression showed LV end diastolic diameter as a significant determinant of variation for LS. Longitudinal systolic strain rate (LSRs) was significantly determined by the age and RS by the type of vendor used.ConclusionVariations among different normal ranges were dependent on the vendor used, LV end-diastolic diameter and age. Vendor-independent software for analyzing myocardial deformation in children, using images from different vendors would be the ideal solution for strain measurements or else using the same system for patient’s follow up.

Left ventricular response to pressure afterload in children : aortic stenosis and coarctation A systematic review of the current evidence

Congenital aortic stenosis (CAS) and Coarctation of Aorta (CoA) represent two forms of pressure afterload that affect the left ventricle (LV), hence require regular echocardiographic monitoring. Subclinical dysfunction of the LV exists even in asymptomatic patients with preserved left ventricular ejection fraction (EF), implying low sensitivity of EF in predicting optimum time for intervention. In this article we review patterns of LV myocardial deformation before and after correction of CAS and CoA in infants, children and adolescents, showing their important role in monitoring the course of LV dysfunction. A systematic search using PubMed was performed and suitable studies are presented on a narrative form. Normal EF and/or fractional shortening (FS), with subclinical myocardial dysfunction are reported in all studies before intervention. The short-term results, after intervention, were related to the type of procedure, with no improvement or further deterioration related to surgery but immediate improvement after balloon intervention. Long term follow-up showed further improvement but still subnormal function. Thus correction of CAS and CoA before irreversible LV dysfunction is vital, and requires longitudinal studies in order to identify the most accurate parameter for function prognostication. Until then, conventional echocardiographic parameters together with myocardial velocities and deformation parameters should continue to provide follow-up reproducible measures of ventricular function.

Persistent reduced myocardial deformation in neonates after CoA repair

INTRODUCTION Surgical repair of coarctation of the aorta (CoA) is a safe procedure in children, however the condition is known for its potential recurrence and other related complications. The available evidence shows abnormal intrinsic properties of the aorta in CoA, thus suggesting additional effect, even after CoA repair, on left ventricular (LV) function. Accordingly, we sought to obtain a better understanding of LV myocardial mechanics in very early-corrected CoA using two-dimensional STE. METHODS AND RESULTS We retrospectively studied 21 patients with corrected CoA at a median age of 9 (2-53) days at three time points: 1) just before intervention, 2) at short-term follow-up and 3) at medium-term follow-up after intervention and compared them with normal values. Speckle tracking analysis was conducted via vendor independent software, Tomtec. After intervention, LV function significantly improved (from -12.8±3.9 to -16.7±1.7; p<0.001), however normal values were not reached even at medium term follow-up (-18.3±1.7 vs. -20±1.6; p=0.002). Medium term longitudinal strain correlated with pre intervention EF (r=0.58, p=0.006). Moreover, medium term subnormal values were more frequently associated with bicuspid aortic valve (33.3% vs. 66.6%; p<0.05). CONCLUSION LV myocardial function in neonates with CoA can be feasibly evaluated and followed up by speckle tracking echocardiography. LV subendocardial dysfunction however, remains in early infancy coarctation long after repair. Long-term follow-up through adulthood using myocardial deformation measurements should shed light on the natural history and consequences of this anomaly.

Coarctation repair normalizes left ventricular function and aorto-septal angle in neonates

BACKGROUND AND AIMS Patients with coarctation of the aorta (CoA) have increased left ventricular (LV) afterload that has been shown to impact the LV and ascending aortic function. We aimed to examine the effect of coarctation on LV function and aorto-septal angle (AoSA) before and after surgical repair. METHODS We retrospectively studied 21 patients with surgically repaired CoA at a median age of 9 (2-53) days at three time points: (1) just before intervention, (2) at short-term follow-up, and (3) at medium-term follow-up after intervention. AoSA was measured from the parasternal long axis view, at three time points during the cardiac cycle: (1) end diastole, (2) beginning of systole, and (3) at peak ejection in the descending aorta. In addition to conventional LV structure and function, global longitudinal strain, and strain rate were measured using STE technique and Tomtec software. Three groups of age matched healthy children served as controls at each time point. RESULTS AoSA was significantly wider before intervention, in particular at peak ejection in the descending aorta (144° ± 6.4° vs. 136° ± 4.1°; P < .0001), and correlated with CoA pressure gradient. After intervention, AoSA normalized and significantly correlated with the increase of LV cavity function and overall LV deformation parameters. CONCLUSIONS AoSA is abnormally wide in neonates with CoA and is associated with severity of obstruction, LV dysfunction and compromised LV global deformation.