Pediatric Normal Values and Z Score Equations for Left and Right Ventricular Strain by Two-Dimensional Speckle-Tracking Echocardiography Derived from a Large Cohort of Healthy Children

Normal Values for Speckle-Tracking Echocardiography in Children: A Review, Update, and Guide for Clinical Use of Speckle-Tracking Echocardiography in Pediatric Patients

Background/Objectives: While speckle-tracking echocardiography (STE) is increasingly gaining acceptance in the medical community, establishing normal pediatric values and interpreting data derived from software provided by various vendors can pose significant challenges. This review aims to present an updated compilation of nomograms pertinent to speckle-tracking echocardiography. Methods: A review of research using three medical engine searches (National Library of Medicine, Science Direct, and Cochrane Library) for Medical Subject Headings (MeSH) and the free text terms "echocardiography", "STE", "normal values", and "children" was performed and refined by adding the keywords "nomograms", "z-scores", and "healthy children". Results: A total of twenty-five studies were selected for the final analysis. Our research indicated that current nomograms provide adequate coverage of most strain parameters; however, those pertaining to the right ventricle and the atria are less numerous than those for the left ventricle. A noted trend suggests a decrease in strain values with advancing age and increasing body surface area; nevertheless, the relationships observed were weak and nonlinear. The absence of robust correlations between strain values and age and body size parameters hindered the generation of a Z-score possessing sufficient statistical power. Consequently, normal values are primarily represented as mean values accompanied by standard deviation. A comparative analysis of vendors demonstrated good agreement between different versions of the same platform for Philips (except for QLAB 5) and, similarly, between General Electric (GE) and TomTec. The limited data available regarding the comparison between GE and Philips revealed significant findings that warrant further investigation of differences. Conclusions: A comprehensive review and an updated list of current pediatric nomograms for STE measurements have been presented. This may serve as a valuable guide for accurately interpreting STE in pediatric patients with congenital and acquired heart disease.

The importance of the Autostrain RV technique in the treatment of right ventricular myocardial alterations in patients with breast cancer receiving chemotherapy

To research the value of Autostrain right ventricular (RV) technology in detecting and preventing right ventricular myocardial injury in patients undergoing breast cancer chemotherapy by providing an imaging basis for early identification. To examine the changes in various cardiac function parameters before and after chemotherapy, two-dimensional echocardiography was employed 48 h before chemotherapy, 48 h after the fourth cycle of chemotherapy, and 48 h after the eighth cycle of chemotherapy, respectively. The patients included those with breast cancer who underwent surgery and were primarily administered anthracycline-based chemotherapeutic drugs. (1) Compared with the pre-chemotherapy period, the absolute values of the right ventricular global longitudinal strain (RV4CSL) and right ventricular free-wall longitudinal strain (RVFWSL) decreased after the fourth chemotherapy cycle, and no significant differences were observed in tricuspidannular plane systolic excursion (TAPSE), right ventricular Tei index, and right ventricular fractional area change (FAC); (2) Compared with the pre-chemotherapy period, the absolute values of RV4CSL and RVFWSL decreased after the eighth chemotherapy cycle. TAPSE and FAC decreased, the right ventricular Tei index increased; (3) Compared with the end of the fourth chemotherapy cycle, the absolute values of RV4CSL and RVFWSL decreased at the end of the eighth chemotherapy cycle. TAPSE, right ventricular Tei index and FAC were not significantly different. (4) Pearson correlation analysis revealed a correlation between the absolute value of RV4CSL, the absolute value of RVFWSL, right ventricular Tei index, TAPSE and FAC. The absolute values of RV4CSL and RVFWSL are sensitive indices that reflect changes in the right ventricular myocardium in the early stages of chemotherapy. They can reflect the effects of anthracycline on the right ventricular myocardium of patients with breast cancer earlier than the TAPSE, FAC and right ventricular Tei indices. A relationship exists between the absolute value of RVFWSL, the absolute value of RV4CSL, right ventricular Tei index, TAPSE, FAC and anthracycline-induced alterations in the right ventricular myocardium. This study is helpful for early detection of right ventricular myocardial function injury caused by anthracyclines in breast cancer patients, and provides imaging basis for early clinical detection and prevention of right ventricular myocardial injury.

Use of Right Ventricular Free-Wall Strain in a Multivariable Estimate of Right Ventricular-Arterial Coupling in Pediatric Pulmonary Arterial Hypertension

BACKGROUND

Right ventricular-arterial coupling (RVAC) describes the relationship between right ventricular contractility and pulmonary vascular afterload. Noninvasive surrogates for RVAC using echocardiographic estimates of right ventricular function, such as tricuspid annular plane systolic excursion (TAPSE), have been shown to correlate with invasively measured RVAC and predict clinical outcomes in pediatric pulmonary arterial hypertension. However, given the limitations of TAPSE at accurately estimating right ventricular function in children, we hypothesized that a multivariable estimate of RVAC using right ventricular free-wall longitudinal strain (RVFW-LS) may perform better than those utilizing TAPSE at predicting clinical outcomes.

METHODS

In all, 108 children from 2 institutions with pulmonary arterial hypertension underwent hemodynamic catheterization with simultaneous echocardiography. In a retrospective analysis, hybrid (echo and invasive) RVAC metrics included TAPSE/pulmonary vascular resistance (PVRi) and RVFW-LS/PVRi. Noninvasive echocardiographic metrics were TAPSE/echo-derived pulmonary artery systolic pressure (PASP) and RVFW-LS/PASP.

RESULTS

RVFW-LS correlated with PVRi (r=0.315, P=0.01), though TAPSE did not (r=0.058, P=0.64). PVRi, PASP, and RVAC metrics declined in patients with worse World Health Organization Functional Class (n=108), while TAPSE and RVFW-LS did not. PVRi, PASP, RVFW-LS/PVRi, TAPSE/PVRi, and RVFW-LS/PASP predicted the outcome variable of transplant or death (area under the curve, 0.771 [P<0.001], 0.729 [P=0.004], 0.748 [P=0.002], 0.732 [P=0.009], and 0.714 [P=0.01], respectively), while TAPSE/PASP, RVFW-LS, and TAPSE did not (area under the curve, 0.671, 0.603, and 0.525, respectively). In patients without a history of repaired congenital heart disease (n=88), only RVFW-LS/PASP, PVRi, PASP, and RVFW-LS/PVRi predicted outcomes (area under the curve, 0.738 [P=0.002], 0.729 [P=0.01], 0.729 [P=0.01], and 0.729 [P=0.015], respectively).

CONCLUSIONS

In the pediatric population, baseline PVRi and echo-estimated PASP were strongly associated with adverse clinical outcomes, but TAPSE and RVFW-LS were not. Estimates of RVAC utilizing RVFW-LS were superior to those utilizing TAPSE-however, only marginally additive to PASP and PVRi at predicting the adverse clinical outcome in patients without a history of repaired congenital heart disease.

Assessment of Biventricular Systolic and Diastolic Function Using Conventional and Strain Echocardiography in Children with Sickle Cell Disease Surviving 1-year After Hematopoietic Stem Cell Transplant

Hematopoietic stem cell transplant (HSCT) is a potentially curative therapy for children with sickle cell disease (SCD). The effects of HSCT on ventricular function are not well characterized in children with SCD. Echocardiograms from children with SCD who underwent HSCT between 2007 and 2017 were retrospectively analyzed before and 1-year after HSCT. Left ventricular (LV) volumes, mass, and ejection fraction were calculated by the 5/6 area*length method. LV end-diastolic and systolic dimensions, septal, and posterior wall thickness, and fractional shortening were measured by M-mode. Mitral and tricuspid inflow Dopplers (E and A waves) as well as mitral, tricuspid, and septal tissue Dopplers (E', A') were assessed. E/A, E'/A' and E/E' ratios were calculated. Biventricular strain imaging was performed using speckle-tracking echocardiography. Peak global systolic longitudinal and circumferential LV strain, and global longitudinal right ventricular strain, as well as early and late diastolic strain rate, were measured on LV apical 4-chamber, LV short-axis mid-papillary, and RV apical views, respectively. Forty-seven children (9.7 ± 5.5 years, 60% male) met inclusion criteria. Pre-HSCT, subjects had mild LV dilation with normal LV systolic function by conventional measure of ejection fraction and fractional shortening. There was a significant reduction in LV volume, mass, and ejection fraction after HSCT, but measurements remained within normal range. LV longitudinal and circumferential strain were normal pre-HSCT and showed no significant change post-HSCT. RV strain decreased after HSCT, but the absolute change was small, and mean values were normal both pre- and post-HSCT. Conventional measures of diastolic function were all normal pre-HSCT. Post-HSCT there was a reduction in select parameters, but all parameters remained within normal range. Early and late diastolic strain rate parameters showed no significant change from pre- to post-HSCT. At one-year after HSCT in children with SCD conventional measures of systolic and diastolic function are within normal limits. Except for a small decrease in RV systolic strain with values remaining within normal limits, systolic strain and diastolic strain rate values did not significantly change 1-year after HSCT.

Hypertension and Left Ventricular Strain in Pediatric Chronic Kidney Disease

BACKGROUND

Left ventricular global longitudinal strain (LV GLS) on echocardiography is a sensitive yet clinically significant marker of myocardial dysfunction. Reduced LV GLS is prevalent in adults with chronic kidney disease and hypertension and is associated with adverse cardiovascular outcomes. It may be a biomarker of chronic kidney disease-associated myocardial dysfunction in children, but data are limited. Our objective was to describe LV GLS in the CKiD study (Chronic Kidney Disease in Children) and to examine the association between blood pressure (BP) and reduced LV GLS.

METHODS

A single apical 4-chamber view was used to estimate LV GLS. Our main analyses examined the association of clinic BP with the absolute value of LV GLS and LV GLS dichotomized at 16. Sensitivity analyses using 24-hour ambulatory BP monitoring data were also performed. Generalized estimating equations were used to account for within-person correlation and to estimate robust SEs for 95% CIs. Covariates in adjusted models included: age, sex, race, estimated glomerular filtration rate, urine protein, hemoglobin, left ventricular hypertrophy, and the use of renin-angiotensin system inhibitors.

RESULTS

LV GLS was measured in 962 person-visits. A total of 77 assessments had an LV GLS <16. In adjusted models, both clinic systolic BP (odds ratio, 1.02 [95% CI, 1.01-1.03]) and diastolic BP (odds ratio, 1.02 [95% CI, 1.00-1.03]) percentiles were associated with LV GLS <16. Having awake or nighttime diastolic BP hypertension on ambulatory BP monitoring was significantly associated with a lower absolute value of LV GLS.

CONCLUSIONS

Office systolic and diastolic hypertension was associated with diminished LV GLS. Only diastolic hypertension detected on ambulatory BP monitoring was associated with lower LV GLS.

Echocardiographic strain imaging in the pediatric heart: clinical value and utility in decision making

PURPOSE OF REVIEW

Speckle tracking echocardiography (STE)-derived measures of myocardial mechanics, referred to herewithin as strain measurements, directly assess myocardial contractility and provide a nuanced assessment of ventricular function. This review provides an overview of strain measurements and their current clinical value and utility in decision making in pediatric cardiology.

RECENT FINDINGS

Strain measurements are advancing understanding of how cardiac dysfunction occurs in children with acquired and congenital heart disease (CHD). Global strain measurements can detect early changes in cardiac function and are reliable methods of serially monitoring systolic function in children. Global strain measurements are increasingly reported in echocardiographic assessment of ventricular function alongside ejection fraction. Research is increasingly focused on how strain measurements can help improve clinical management, risk stratification, and prognostic insight. Although more research is needed, preliminary studies provide hope that there will be clinical benefit for strain in pediatric cardiology management.

SUMMARY

Strain measurements provide a more detailed assessment of ventricular function than conventional measures of echocardiographic functional assessment. Strain measurements are increasingly being used to advance understanding of normal and abnormal myocardial contractility, to increase sensitivity to detect early cardiac dysfunction, and to improve prognostic management in children with acquired and CHD.

Transcatheter Ductus Arteriosus Stenting for Acute Pediatric Pulmonary Arterial Hypertension is Associated with Improved Right Ventricular Echocardiography Strain

BACKGROUND

Interventional therapies for severe pulmonary arterial hypertension (PAH) can provide right ventricular (RV) decompression and preserve cardiac output. Transcatheter stent placement in a residual ductus arteriosus (PDA) is one potentially effective option in critically ill infants and young children with PAH. We sought to assess recovery of RV function by echocardiographic strain in infants and young children following PDA stenting for acute PAH.

METHODS

Retrospective review of patients < 2 years old who underwent PDA stenting for acute PAH. Clinical data were abstracted from the electronic medical record. RV strain (both total and free wall components) was assessed from echocardiographic images at baseline and 3, 6, and 12 months post-intervention, as well as at last echocardiogram.

RESULTS

Nine patients underwent attempted ductal stenting for PAH. The median age at intervention was 38 days and median weight 3.7 kg. One-third (3of 9) of patients had PAH associated with a congenital diaphragmatic hernia. PDA stents were successfully deployed in eight patients. Mean RV total strain was - 14.9 ± 5.6% at baseline and improved to - 23.8 ± 2.2% at 6 months post-procedure (p < 0.001). Mean free wall RV strain was - 19.5 ± 5.4% at baseline and improved to - 27.7 ± 4.1% at 6 months (p = 0.002). Five patients survived to discharge, and four patients survived 1 year post-discharge.

CONCLUSION

PDA stenting for severe, acute PAH can improve RV function as assessed by strain echocardiography. The quantitative improvement is more prominent in the first 6 months post-procedure and stabilizes thereafter.

Advanced Echocardiography Assessment in the Management of Alcapa Syndrome: Case Report

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare and potentially life-threatening condition affecting infants that requires immediate corrective surgery to restore blood flow to the myocardium. We present a case of an infant with ALCAPA and severe heart failure. What sets this case apart is the utilization of speckle-tracking echocardiography as a non-invasive method for assessing global and regional myocardial function before and after surgical intervention. Our preoperative analysis revealed compromised contraction in specific areas of the left ventricle (LV), in the regions that were supplied by both the left coronary artery (LCA) and the right coronary artery (RCA). Interestingly, despite an increase in ejection fraction (EF) measured by conventional echocardiography, the postoperative speckle-tracking analysis revealed persistent impairment in the anterior territories supplied by LCA, highlighting the potential of this technique in identifying myocardial abnormalities during postoperative follow-up. In conclusion, speckle-tracking echocardiography may be a valuable tool for identifying subtle myocardial changes in ALCAPA patients with a higher sensitivity in detecting regional left ventricular (LV) dysfunction compared to conventional echocardiography.

Use of Speckle-Tracking Echocardiography in Septic Cardiomyopathy in Critically Ill Children: A Narrative Review

OBJECTIVES

In critically ill children with severe sepsis, septic cardiomyopathy (SCM) denotes the subset of patients who have myocardial dysfunction with poor response to fluid and inotropic support, and higher mortality risk. The objective of this review was to evaluate the role of speckle-tracking echocardiography (STE) in the diagnosis and prognosis of pediatric SCM in the PICU setting.

DATA SOURCES

We performed detailed searches using PubMed, Scopus, Web of Science, and Google Scholar. Reference lists of all included studies were also examined for further identification of potentially relevant studies.

STUDY SELECTION

Studies with the following medical subject headings and keywords were selected: speckle-tracking echocardiography, strain imaging, global longitudinal strain, echocardiography, sepsis, severe sepsis, septic shock, septic cardiomyopathy, and myocardial dysfunction.

DATA EXTRACTION

The following data were extracted from all included studies: demographics, diagnoses, echocardiographic parameters, severity of illness, PICU management, and outcomes.

DATA SYNTHESIS

STE is a relatively new echocardiographic technique that directly quantifies myocardial contractility. It has high sensitivity in diagnosing SCM, correlates well with illness severity, and has good prognosticating value as compared with conventional echocardiographic parameters. Further studies are required to establish its role in evaluating biventricular systolic and diastolic dysfunction, and to investigate whether it has a role in individualizing treatment and improving treatment outcomes in this group of patients.

CONCLUSIONS

STE is a useful adjunct to conventional measures of cardiac function on 2D-echocardiography in the assessment of pediatric SCM in the PICU.

Clinical and pathophysiologic determinants of catheter ablation outcome in hypertrophic cardiomyopathy with atrial fibrillation

Background

Hypertrophic cardiomyopathy (HCM) is frequently associated with atrial fibrillation (AF). We compared clinical, echocardiographic, and electrophysiological parameters between HCM subtypes and those without HCM at AF catheter ablation (AFCA) and analyzed post-AFCA reverse remodeling and AF recurrence based on HCM presence and subtype.

Methods

Among 5161 consecutive patients who underwent de novo AFCA, we included HCM patients and control patients who were age-, gender-, and AF type-matched. Between AF-HCM patients and controls, we compared baseline values for left atrium (LA) wall thickness (LAWT), reverse remodeling at 1-year follow-up, and procedural outcomes over the course of follow-up between two groups.

Results

A total of 122 AF-HCM patients and 318 control patients were included. AF-HCM patients had more frequent heart failure and higher LA diameter, E/Em, and LA pressure (all, p < .001). However, LAWT did not differ from control group. A year after AFCA, degree of LA reverse remodeling was significantly lower in AF-HCM than in control group (ΔLA dimension, p = .025). Nonapical HCM (HR 1.71; 95% CI 1.05-2.80), persistent AF (HR 1.46; 95% CI 1.05-2.04), and LA dimension (HR 1.04; 95% CI 1.01-1.06) were independent risk factors for AF recurrence. During 78.0 months of follow-up, nonapical HCM patients showed higher AF recurrence rate than both apical HCM (log-rank p = .005) and control patients (log-rank p = .002).

Conclusions

The presence of HCM, particularly nonapical HCM, displayed increased LA hemodynamic loading with diastolic dysfunction and had poorer rhythm outcomes after AFCA compared to both apical HCM and control group.

Baseline Echocardiography and Laboratory Findings in MIS-C and Associations with Clinical Illness Severity

Children with COVID-associated multisystem inflammatory syndrome (MIS-C) may develop severe disease. We explored the association of admission echocardiographic and laboratory parameters with MIS-C disease severity. This retrospective, single center study of consecutive MIS-C patients (4/2020-12/2021) excluded those with preexisting cardiomyopathy, congenital heart disease, or prior cardiotoxic therapy. Our hypothesis was that worse admission echocardiographic and laboratory parameters were associated with more severe disease based on vasoactive medication use. Univariable and multivariable logistic regression models assessed the association between vasoactive medication use and baseline variables. Of 118 MIS-C patients, median age was 7.8 years (IQR 4.6, 11.8), 48% received vasoactive medication. Higher admission brain natriuretic peptide [OR 1.07 (95% CI 1.02,1.14), p = 0.019], C-reactive protein [OR 1.08 (1.03,1.14), p = 0.002], troponin [OR 1.05 (1.02,1.1), p = 0.015]; lower left ventricular ejection fraction [LVEF, OR 0.96 (0.92,1), p = 0.042], and worse left atrial reservoir strain [OR 0.96 (0.92,1), p = 0.04] were associated with vasoactive medication use. Only higher CRP [OR 1.07 (1.01, 1.11), p = 0.034] and lower LVEF [0.91 (0.84,0.98), p = 0.015] remained independently significant. Among those with normal admission LVEF (78%, 92/118), 43% received vasoactive medication and only higher BNP [OR 1.09 (1.02,1.19), p = 0.021 per 100 pg/mL] and higher CRP [OR 1.07 (1.02,1.14), p = 0.013] were associated with use of vasoactive medication. Nearly half of all children admitted for MIS-C subsequently received vasoactive medication, including those admitted with a normal LVEF. Similarly, admission strain parameters were not discriminatory. Laboratory markers of systemic inflammation and cardiac injury may better predict early MIS-C disease severity.

Impaired echocardiographic left ventricular global longitudinal strain after pediatric cardiac arrest children is associated with mortality

BACKGROUND

Global longitudinal strain (GLS) is an echocardiographic method to identify left ventricular (LV) dysfunction after cardiac arrest that is less sensitive to loading conditions. We aimed to identify the frequency of impaired GLS following pediatric cardiac arrest, and its association with hospital mortality.

METHODS

This is a retrospective single-center cohort study of children <18 years of age treated in the pediatric intensive care unit (PICU) after in- or out-of-hospital cardiac arrest (IHCA and OHCA), with echocardiogram performed within 24 hours of initiation of post-arrest PICU care between 2013 and 2020. Patients with congenital heart disease, post-arrest extracorporeal support, or inability to measure GLS were excluded. Echocardiographic LV ejection fraction (EF) and shortening fraction (SF) were abstracted from the chart. GLS was measured post hoc; impaired strain was defined as LV GLS ≥ 2 SD worse than age-dependent normative values. Demographics and pre-arrest, arrest, and post-arrest characteristics were compared between subjects with normal versus impaired GLS. Correlation between GLS, SF and EF were calculated with Pearson comparison. Logistic regression tested the association of GLS with mortality. Area under the receiver operator curve (AUROC) was calculated for discriminative utility of GLS, EF, and SF with mortality.

RESULTS

GLS was measured in 124 subjects; impaired GLS was present in 46 (37.1%). Subjects with impaired GLS were older (median 7.9 vs. 1.9 years, p < 0.001), more likely to have ventricular tachycardia/fibrillation as initial rhythm (19.6% versus 3.8%, p = 0.017) and had higher peak troponin levels in the first 24 hours post-arrest (median 2.5 vs. 0.5, p = 0.002). There were no differences between arrest location or CPR duration by GLS groups. Subjects with impaired GLS compared to normal GLS had lower median EF (42.6% versus 62.3%) and median SF (23.3% versus 36.6%), all p < 0.001, with strong inverse correlation between GLS and EF (rho -0.76, p < 0.001) and SF (rho -0.71, p < 0.001). Patients with impaired GLS had higher rates of mortality (60% vs. 32%, p = 0.009). GLS was associated with mortality when controlling for age and initial rhythm [aOR 1.17 per 1% increase in GLS (95% CI 1.09-1.26), p < 0.001]. GLS, EF and SF had similar discrimination for mortality: GLS AUROC 0.69 (95% CI 0.60-0.79); EF AUROC 0.71 (95% CI 0.58-0.88); SF AUROC 0.71 (95% CI 0.61-0.82), p = 0.101.

CONCLUSIONS

Impaired LV function as measured by GLS after pediatric cardiac arrest is associated with hospital mortality. GLS is a novel complementary metric to traditional post-arrest echocardiography that correlates strongly with EF and SF and is associated with mortality. Future large prospective studies of post-cardiac arrest care should investigate the prognostic utilities of GLS, alongside SF and EF.

Cardiac dysfunction in severe pediatric acute respiratory distress syndrome: the right ventricle in search of the right therapy

Severe acute respiratory distress syndrome in children, or PARDS, carries a high risk of morbidity and mortality that is not fully explained by PARDS severity alone. Right ventricular (RV) dysfunction can be an insidious and often under-recognized complication of severe PARDS that may contribute to its untoward outcomes. Indeed, recent evidence suggest significantly worse outcomes in children who develop RV failure in their course of PARDS. However, in this narrative review, we highlight the dearth of evidence regarding the incidence of and risk factors for PARDS-associated RV dysfunction. While we wish to draw attention to the absence of available evidence that would inform recommendations around surveillance and treatment of RV dysfunction during severe PARDS, we leverage available evidence to glean insights into potentially helpful surveillance strategies and therapeutic approaches.