Developments in echocardiographic techniques for the evaluation of ventricular function in children

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.

Echocardiographic Markers of Mild Pulmonary Hypertension are not Correlated with Worse Respiratory Outcomes in Infants with Bronchiolitis

Pulmonary hypertension has been reported as a crucial factor in the pathophysiology of severe bronchiolitis. The aim of this study was to evaluate pulmonary artery pressure (PAP) in patients with bronchiolitis and to analyze their correlation with clinical outcomes. This prospective cohort study examined children admitted for bronchiolitis. PAP was assessed by right ventricle (RV) acceleration/ejection time ratio (AT/ET), isovolumic relaxation time, eccentricity index, and the presence of a pulmonary systolic notch. Pulmonary hypertension (PH) was considered if at least two altered parameters were present. Severity of clinical course was established by higher N-terminal (NT)-prohormone BNP (NT-proBNP) values, the need for positive pressure respiratory support (PPRS), and the duration of hospital admission. One hundred sixty-nine children were included in analysis. Sixty-eight patients (40%) required PPRS, and those patients had increased NT-proBNP values and worse tricuspid annular systolic excursion (TAPSE) compared to mild cases (p < 0.001and p < 0.001, respectively). Twenty-two (13%) cases had at least two altered parameters of PAP and met criteria for presumed PH, with no differences in NT-proBNP values, TAPSE, need for PPRS or hospital length of stay compared to normal PAP group (p = 0.98, p = 0.07, p = 0.94 and p = 0.64, respectively). We found no correlation between altered RV AT/ET and worse cardiac function, NT-proBNP values or hospital length of stay. In our cohort, the presence of echocardiographic findings of PH were not associated with worse clinical outcomes. Patients with severe bronchiolitis had higher values ​​of NT-proBNP but, interestingly, no clear association with PH.

Cardiac function in bronchiolitis: Not only a right ventricle matter

OBJECTIVES

Extrapulmonary manifestations of bronchiolitis have been previously studied, with some identifying right ventricle (RV) diastolic/systolic dysfunction. We hypothesized that severe cases of bronchiolitis would have cardiac dysfunction resulting an increase in N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP) values and worse outcomes. Therefore, the objective was to evaluate the existence of cardiac dysfunction and to determine its association with severe bronchiolitis.

METHODS

This prospective cohort study included children hospitalized for bronchiolitis under 1-year old between January 2019 and March 2020. At admission, an echocardiography was performed and plasma levels of NT-proBNP were measured. To analyze outcomes, the cohort was divided into two groups based on the need for positive pressure respiratory support (PPRS), and both were compared to healthy infants.

STATISTICS

bivariant analysis, significant differences p < 0.05.

RESULTS

One hundred eighty-one patients were included; median age was 2 months. Seventy-three patients required PPRS. Compared to controls, patients requiring PPRS showed worse RV systolic function, with lower tricuspid annular-plane systolic excursion (p = 0.002) and parameters of worse right and left diastolic function (trans-tricuspid E and A wave [p = 0.004 and p = 0.04, respectively] and tricuspid tissue doppler imaging [TDI] e' [p = 0.003], trans-mitral E and mitral TDI a' [p = 0.02 and p = 0.005, respectively]). An NT-ProBNP greater than 3582 pg/dl predicts the need for longer necessity of PPRS in patients younger than 2 months.

CONCLUSIONS

In addition to the expected RV systolic dysfunction, patients with severe bronchiolitis have parameters of global diastolic worse function possibly secondary to intrinsic myocardial involvement. NT-ProBNP values at admission had strong discriminatory power to predict worse outcomes.

Right ventricular function in β-thalassemia children: comparing three-dimensional echocardiography with other functional parameters

BACKGROUND

Cardiomyopathy is a major cause of mortality and morbidity in beta-thalassemia major (β-TM), and its early detection is critical for prompt management. We aimed to evaluate right ventricle (RV) function in β-TM, in absence of cardiac symptoms, using 3D echocardiography, and compare it with other functional parameters.

METHODS

Cross-sectional cohort study was conducted on 50 β-TM children with no cardiac manifestations and 50 healthy controls of matched age and sex. We evaluated RV function using; Fraction Area Change (2DE-RV FAC), Ejection Fraction (3D-RVEF), Tricuspid annular plane systolic excursion (TAPSE), Tissue Doppler imaging (TDI) systolic (S') and diastolic (E', A'), Myocardial performance index (MPI), and speckle tracking (2D-STE) of RV global longitudinal strain (LSS), systolic strain rate (SSR), early diastolic strain rate (DSR E), and late diastolic strain rate (DSR A).

RESULTS

3D-RVEF, MPI, and 2D-STE showed significant differences between the two groups. ROC curve analysis measurements had an AUC above 0.7-which indicate at least a fair discriminatory power between the β-TM group with RV dysfunction and normal controls.

CONCLUSIONS

β-TM patients have decreased RV function indices at a pre-symptomatic stage. Early detection of RV dysfunction is feasible and can allow for closer follow-up to detect pre-clinical changes.

IMPACT

The key message of this article is to emphasize the importance of the evaluation of right ventricular function in children with beta-thalassemia major. This article adds to the existing literature the use of recent echocardiographic modalities as three-dimensional echocardiography and two-dimensional speckle tracking in the evaluation of right ventricular dysfunction in beta-thalassemia children while cardiac affection is still subclinical.

IMPACT

Recent echocardiographic functional parameters can be effectively used to evaluate the right ventricle in beta-thalassemia and can detect dysfunction in asymptomatic patients allowing for early intervention.

Early postnatal cardiac follow-up of survivors of twin-twin transfusion syndrome treated with fetoscopic laser coagulation

OBJECTIVE

To assess the cardiac function and prevalence of congenital heart defects (CHD) in twin-twin transfusion syndrome (TTTS) survivors.

STUDY DESIGN

Prospective follow-up of TTTS pregnancies treated with laser surgery (2015-2018). Echocardiography was performed 1 day and 1 month after birth (corrected for prematurity). Results were compared with a control group of age-matched uncomplicated monochorionic twin-pairs at 1 month.

RESULT

Eighty-nine TTTS (168 neonates) and nine control pregnancies (18 neonates) were enrolled. CHD birth prevalence was 9.2% (8/87) in recipients and 13.6% (11/81) in donors (p = 0.37). Four of 19 (21%) were detected prenatally, all pulmonary stenosis. Donors had lower aortic peak velocities compared with recipients at day 1 (0.66 ± 0.15 m/s vs 0.71 ± 0.19 m/s, p = 0.04) and 1 month (1.04 ± 0.21 m/s vs 1.11 ± 0.18 m/s, p = 0.02), but not compared with controls.

CONCLUSION

CHD prevalence in TTTS survivors is high, with a low prenatal detection of minor abnormalities. Follow-up fetal echocardiograms and a postnatal echocardiogram should be offered.

Changes in the Interventricular Septal Curvature in Healthy Full-term Neonates During the First 14 Days of Life

OBJECTIVES

Interventricular septal geometry and motion reflect the interaction between the ventricles, and an abnormal shape and abnormal motion are always regarded as signs of increased right ventricular or pulmonary artery pressure. During the neonatal period, there are profound changes in the cardiac circulation. The aims of this study were to quantitatively analyze neonatal septal deformations under normal physiologic conditions and evaluate the changes in association with the hemodynamic changes occurring during the transitional period.

METHODS

This was a retrospective study of 114 healthy full-term neonates from birth to 14 days of age. Normalized septal curvatures were measured on left ventricular parasternal short-axis views during end diastole and end systole. The interventricular pressure gradient, ratio of ventricular volumes, septal strain, thickness, and some clinical characteristics were assessed, along with the association of these parameters with septal curvature.

RESULTS

All 4 normalized septal curvatures were found to have a significant correlation with the trans-septal pressure gradient (TSPG) and the end-diastolic volume ratio of the left and right ventricles (P < .0001). The TSPG had the highest impact on septal curvature, and among the 4 curvatures, the middle end-systolic normalized septal curvature had the highest correlation with the TSPG (r² = 0.948; P < .0001).

CONCLUSIONS

There were significant correlations between septal curvature and the interventricular pressure gradient and ventricular volume ratio in healthy full-term neonates. The normalized septal curvatures gradually increased with increasing age and could be good indicators of the hemodynamic changes occurring during the transitional period.

Assessment of cardiac function and electrocardiographic findings in patients with Wilson's disease

BACKGROUND

This study evaluated cardiac function using tissue Doppler echocardiography and assessed electrocardiographic findings in children diagnosed with Wilson's disease.

METHOD

Asymptomatic patients with a diagnosis of Wilson's disease (n = 43) were compared to healthy controls (n = 37) that were age and gender matched.

RESULTS

The standard electrocardiographic and conventional echocardiographic examinations were similar in both groups. The left ventricular ejection fraction, shortening fraction, and diastolic function were not significantly different between the two groups. The Tei index for mitral lateral, mitral septal, tricuspid lateral, tricuspid septal, and inter-ventricular septum on tissue Doppler echocardiography was higher in the patient group, yet it did not reach statistical significance. Mitral lateral and septal systolic annular velocity values were significantly lower in the patient group when compared to the control group (p = 0.02 and 0.04, respectively). Also, mitral lateral and septal isovolumetric contraction time values were higher in the patient group (p = 0.04). Although the left ventricular values were not significantly different, relative left ventricular wall thickness was higher in the patient group when compared to the control group, and concentric remodelling in the left ventricle was found in 7 (16%) of 42 patients. QT interval (p = 0.02) and P-wave dispersion values (p = 0.04) were significantly higher in the patient group compared to the control group, and these tend to predict arrhythmias.

CONCLUSION

Our study based on the tissue Doppler echocardiography assessment indicated a subclinical systolic, rather than diastolic, dysfunction in the myocardium with increased QT interval and P-wave dispersion, despite the young age of the patients and short disease duration.

Intravenous immunoglobulins in children with new onset dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy is a rare but serious disorder in children. No effective diagnostic or treatment tools are readily available. This study aimed to evaluate the efficacy of intravenous immunoglobulins in children with new onset dilated cardiomyopathy. Methods and results In this retrospective cohort study, 94 children with new onset dilated cardiomyopathy were followed during a median period of 33 months. All patients with secondary dilated cardiomyopathy - for example, genetic, auto-immune or structural defects - had been excluded. Viral tests were performed in all patients and 18 (19%) children met the criteria for the diagnosis "probable or definite viral myocarditis". Intravenous immunoglobulins were administered to 21 (22%) patients. Overall transplant-free survival was 75% in 5 years and did not differ between treatment groups. The treatment was associated with a higher recovery rate within 5 years, compared with non-treated children (70 versus 43%, log rank=0.045). After correction for possible confounders the hazard ratio for recovery with intravenous immunoglobulins was not significant (hazard ratio: 2.1; 95% CI: 1.0-4.6; p=0.056). Administration of intravenous immunoglobulins resulted in a greater improvement in the shortening fraction of the left ventricle.

CONCLUSION

In our population of children with new onset dilated cardiomyopathy, of either viral or idiopathic origin, intravenous immunoglobulins were administered to a minority of the patients and did not influence transplant-free survival, but were associated with better improvement of systolic left ventricular function and with better recovery. Our results support the concept that children with new onset dilated cardiomyopathy might benefit from intravenous immunoglobulins.

Clinical study of right ventricular longitudinal strain for assessing right ventricular dysfunction and hemodynamics in pulmonary hypertension

This study aimed to appraise the application of right ventricular longitudinal strain for assessing right ventricular dysfunction and severe hemodynamic changes in pulmonary hypertension. The study included 53 patients clinically diagnosed with PH. Tissue Doppler-derived tricuspid lateral annular systolic velocity (s'), early diastolic peak velocity (e'), late diastolic peak velocity (a'), tricuspid annular plane systolic excursion (TAPSE), RV index of myocardial performance (RIMP), and right ventricular fractional area change (FAC) were determined. The STI parameter was RV free wall longitudinal peak systolic strain (RV LPSS). The patients were assigned into two groups based on a RV LPSS value of - 19%.RV LPSS, s', TAPSE, RIMP, FAC, a' and e'/a' showed significant differences. PH patients with an RV LPSS≥ -19% exhibited a lower RV function (P < 0.05). RV LPSS was negatively correlated with TAPSE (r = -0.326, P < 0.05) and FAC (r = -0.495, P < 0.001) and positively correlated with RIMP (r = 0.508, P < 0.001). The optimal cut-off value of RV LPSS to reveal an mPAP ≥ 45 mmHg defined based on the receiver operating characteristic curve analysis was - 19.26% with a sensitivity of 83.9% and a specificity of 73.4%.Distinguishing the degree of RV dysfunction by 2D-STI may help physicians to determine the state of cardiac function and degree of PH in patients and offer a basis for subsequent clinical diagnosis and therapy. Our study demonstrates the superiority of RV LPSS for uncovering severe PH over the traditional echocardiographic parameters.

Impaired Left Ventricular Longitudinal Function in Idiopathic Pulmonary Arterial Hypertension Children

Background: Pulmonary arterial hypertension is associated with right ventricular dilation and failure. As a result, left ventricular geometry is affected by shifting of the interventricular septum towards the left ventricle.

Aim of the study: The aim of the study was to assess the effect of chronic right ventricular pressure overload on left ventricular longitudinal function and synchronicity in idiopathic pulmonary arterial hypertension children, using speckle-tracking echocardiography.

Material and methods: We prospectively evaluated 13 children (5 with idiopathic pulmonary arterial hypertension and 8 sex- and age-matched controls) using conventional and speckle-tracking echocardiography and clinical status (WHO functional class). Left ventricular longitudinal strain curve was generated for 17 segments and global left ventricular longitudinal peak systolic strain was calculated. Dyssynchrony index of the left ventricle was determined calculating the standard deviation of time to peak-systolic strain for 12 left ventricular, 6 basal and 6 midventricular segments, from short axis views.

Results: Strain imaging showed significantly decreased global left ventricular longitudinal strain and increased dyssynchrony index in idiopathic pulmonary arterial hypertension patients as compared with controls (−16.80 ± 2.94 vs. −21.50 ± 1.60, p = 0.003, and 53.80 ± 16.72 vs. 22.25 ± 6.18, p=0.0001, respectively). There was a significant correlation between left ventricular longitudinal strain, dyssynchrony index and right ventricular fractional area changes (r = −0.66, p = 0.013, and r = −0.72, p = 0.005, respectively), right ventricular myocardial performance index (r = 0.86, p = 0.0001, and r = 0.93, p = 0.000, respectively), and LV eccentricity index (r = 0.82, p=0.001, and r = 0.93, p = 0.000, respectively) in the study population as a whole.

Conclusions: Left ventricular longitudinal systolic strain and synchronicity are impaired in idiopathic pulmonary arterial hypertension children with normal left ventricular ejection fraction.

Deformation pattern and predictive value of right ventricular longitudinal strain in children with pulmonary arterial hypertension

BACKGROUND

Right ventricular function has been identified as an important prognostic factor in children with pulmonary arterial hypertension. The aim of the study was to assess the deformation pattern and prognostic value of right ventricular longitudinal strain in children with pulmonary arterial hypertension.

METHODS

We prospectively evaluated 46 children (25 with pulmonary arterial hyperetension and 21 age and sex matched controls) using conventional and speckle-tracking echocardiography, brain natriuretic peptide levels and clinical status expressed by WHO functional class and 6-min walking test. According to the clinical status after 12 months of follow-up, the pulmonary arterial hypertension patients were divided in two groups: non-worsening (13) and worsening (12).

RESULTS

Right ventricular free wall longitudinal strain and strain rate were significantly lower in children with PAH compared with controls (-24.72 ± 3.48 vs -15.60 ± 3.40, p = 0.0001 and -1.44 ± 0.09 vs -1.09 ± 0.15, p = 0.0001, respectively). There was a more expressed decrease of basal than apical region of right ventricular free wall longitudinal strain/strain rate in pulmonary arterial hypertension patients compared with controls (strain: p = 0.0001 vs p = 0.07 and strain rate: p = 0.0001 vs p = 0.002). Comparing worsening and non-worsening pulmonary arterial hypertension patients there was a significant difference in Mid right ventricular free wall longitudinal strain (-14.00 ± 3.13 vs. -20.76 ± 4.62, p = 0.0001). In multivariable logistic regression analysis Mid right ventricular free wall longitudinal strain was an independent predictor of worsening in pulmonary arterial hypertension children (OR 0.45; 95 % CI: 0.21-0.96, p = 0.041). In ROC curve analysis a cut-off value of Mid right ventricular free wall longitudinal strain of -18.50 % predicted clinical worsening in pulmonary arterial hypertension children, with a sensitivity and specificity of 91.7 and 30.8 %, respectively (area under curve = 0.88 ± 0.06, 95 % CI: 0.75-1.00, p = 0.001).

CONCLUSIONS

Two-dimensional speckle-tracking echocardiography is a complementary non-invasive tool for assessment of right ventricular function in children with severe pulmonary arterial hypertension, allowing also clinical prediction and segmental analysis of right ventricular myocardial performance in these patients.

Transthoracic echocardiography in the evaluation of pediatric pulmonary hypertension and ventricular dysfunction

Transthoracic echocardiography (TTE) is the most accessible noninvasive diagnostic procedure for the initial assessment of pediatric pulmonary hypertension (PH). This review focuses on principles and use of TTE to determine morphologic and functional parameters that are also useful for follow-up investigations in pediatric PH patients. A basic echocardiographic study of a patient with PH commonly includes the hemodynamic calculation of the systolic pulmonary artery pressure (PAP), the mean and diastolic PAP, the pulmonary artery acceleration time, and the presence of a pericardial effusion. A more detailed TTE investigation of the right ventricle (RV) includes assessment of its size and function. RV function can be evaluated by RV longitudinal systolic performance (e.g., tricuspid annular plane systolic excursion), the tricuspid regurgitation velocity/right ventricular outflow tract velocity time integral ratio, the fractional area change, tissue Doppler imaging-derived parameters, strain measurements, the systolic-to-diastolic duration ratio, the myocardial performance (Tei) index, the RV/left ventricle (LV) diameter ratio, the LV eccentricity index, determination of an enlarged right atrium and RV size, and RV volume determination by 3-dimensional echocardiography. Here, we discuss the potential use and limitations of TTE techniques in children with PH and/or ventricular dysfunction. We suggest a protocol for TTE assessment of PH and myocardial function that helps to identify PH patients and their response to pharmacotherapy. The outlined protocol focuses on the detailed assessment of the hypertensive RV; RV-LV crosstalk must be analyzed separately in the evaluation of different pathologies that account for pediatric PH.

The relationship between biventricular myocardial performance and metabolic parameters during incremental exercise and recovery in healthy adolescents

Background left ventricular (LV) and right ventricular (RV) myocardial reserve during exercise in adolescents has not been directly characterized. The aim of this study was to quantify myocardial performance response to exercise by using two-dimensional (2-D) speckle tracking echocardiography and describe the relationship between myocardial reserve, respiratory, and metabolic exercise parameters. A total of 23 healthy boys and girls (mean age 13.2 ± 2.7 yr; stature 159.1 ± 16.4 cm; body mass 49.5 ± 16.6 kg; BSA 1.47 ± 0.33 m(2)) completed an incremental cardiopulmonary exercise test (25 W · 3 min increments) with simultaneous acquisition of 2-D transthoracic echocardiography at rest, each exercise stage up to 100 W, and in recovery at 2 min and 10 min. Two-dimensional LV (LV Sl) and RV (RV Sl) longitudinal strain and LV circumferential strain (LV Sc) were analyzed to define the relationship between myocardial performance reserve and metabolic exercise parameters. Participants achieved a peak oxygen uptake (V̇o 2peak) of 40.6 ± 8.9 ml · kg(-1) · min(-1) and a work rate of 154 ± 42 W. LV Sl and LV Sc and RV Sl increased significantly across work rates (P < 0.05). LV Sl during exercise was significantly correlated to resting strain, V̇o 2peak, oxygen pulse, and work rate (0.530 ≤ r ≤ 0.784, P < 0.05). This study identifies a positive and moderate relationship between LV and RV myocardial performance and metabolic parameters during exercise by using a novel methodology. Relationships detected present novel data directly describing myocardial adaptation at different stages of exercise and recovery that in the future can help directly assess cardiac reserve in patients with cardiac pathology.

Evaluation of cardiotoxicity by tissue Doppler imaging in childhood leukemia survivors treated with low-dose anthracycline

Improvement in long-term survival in patients with acute childhood leukemia has led to the need for monitorization of chemotherapy-related morbidity and mortality. This study included 60 patients with acute lymphoblastic leukemia that were in remission for at least 2 years and 30 healthy controls. Systolic and diastolic function of myocardium was evaluated using conventional echocardiography and tissue Doppler imaging of the left ventricle, interventricular septum and right ventricle. Median age of patients was 11.7 years (range 10-14.9 years), and the median duration of remission was 4 years (range 2.5-5 years). All patients were treated with a low cumulative dose of adriamycin (100 mg/m(2)) according to the St. Jude Total-XIIIA protocol. The ejection fraction (EF) and fractional shortening were normal in the patient and control groups, even though EF values were significantly lower in the patients (69.5 ± 2.3 vs. 72.7 ± 3 %, P < 0.01). Myocardial systole (S m), early diastole (E m) and late diastole (A m) velocities in all segments of the myocardium were significantly lower in the patient group (P < 0.01 for all segments). Cardiotoxicity was noted in all segments of the myocardium in the patient group, despite the fact that they were all treated with a low cumulative dose of adriamycin. Based on these findings, we think that there is no safe dose for anthracyclines and periodic echocardiographic evaluation of both the left and right ventricles must be performed in all patients treated with anthracyclines, even at low doses.

Left ventricular strain and strain rates are decreased in children with normal fractional shortening after exposure to anthracycline chemotherapy

BACKGROUND

Anthracycline chemotherapeutic agents carry the well-recognised risk of cardiotoxicity. Previous methods to evaluate cardiac function are useful, but have significant limitations. We sought to determine the left ventricular strain and strain rate of paediatric cancer patients with normal fractional shortening treated with anthracyclines using the latest ultrasound feature-tracking technology.

PATIENTS AND METHODS

Echocardiograms on cancer patients before anthracycline exposure and following completion of treatment were retrospectively analysed using Velocity Vector Imaging software in the circumferential and longitudinal planes. The same analysis was performed on matched controls. Only patients with a fractional shortening ≥28% were included.

RESULTS

In all, 71 patients were identified with an age at diagnosis of 10.5 ± 4.7 years. The time from diagnosis to follow-up was 3.9 ± 4.0 years and the cumulative anthracycline dose was 356 ± 106 mg/m². Following anthracycline exposure, paediatric cancer patients had a higher heart rate and a lower longitudinal strain, longitudinal diastolic strain rate, circumferential strain, and circumferential systolic and diastolic strain rate when compared with controls. Diastolic strain rate showed the greatest percent difference following anthracycline exposure versus controls.

CONCLUSION

Despite having a normal fractional shortening, children exposed to anthracyclines have subclinical derangement of their left ventricular deformation as measured by decreases in strain and strain rate in both the circumferential and longitudinal axis. In particular, there was a profound decrease in diastolic strain rate following anthracycline exposure compared with controls. Whether the decline of strain or strain rate can predict future risk of developing cardiomyopathy requires further investigation.

Development of left ventricular longitudinal speckle tracking echocardiography in very low birth weight infants with and without bronchopulmonary dysplasia during the neonatal period

Objectives

In preterm infants, postnatal myocardial adaptation may be complicated by bronchopulmonary dysplasia (BPD). We aimed to describe the development of left ventricular function by serial 2D, Doppler, and speckle tracking echocardiography (2D-STE) in infants with and without BPD during the neonatal period and compare these to anthropometric and conventional hemodynamic parameters.

Study Design

Prospective echocardiography on day of life (DOL) 1, 7, 14, and 28 in 119 preterm infants <1500 g birth weight of whom 36 developed BPD (need for oxygen supplementation at 36 weeks gestational age). Non-BPD and BPD infants differed significantly in median (IQR) gestational age (25.5(24–26.5) weeks vs. 29(27–30) weeks, p<0.001) and birth weight (661(552–871) g vs. 1100(890–1290) g, p<0.001).

Results

The intra- and inter-observer variability of the 2D-STE parameters measured did not depend on time of measurement, although there were significant differences in the reproducibility of the parameters. Low intra- and inter-observer variability was seen for longitudinal systolic strain and strain rate mid septum with a median CV (coefficient of variation) of <4.6%. Much higher CVs (>10%) were seen for the apical segment. While anthropometric parameters show rapid development during the first 4 weeks of life, the speckle tracking parameters did not differ statistically significantly during the neonatal period. Infants with and without BPD differed significantly (p<0.001) in the development of anthropometric parameters, conventional hemodynamic parameters except for heart rate, and 2D-STE parameters: global longitudinal systolic strain rate (GLSSR) and longitudinal systolic strain for the mid left wall (LSSR). The largest differences were seen at DOL 1 and 7 in GLSSR (p<0.001) and in LSSR (p<0.01).

Conclusions

Reproducible 2D-STE measurements are possible in preterm infants <1500 g. Cardiac deformation reveals early (DOL 1 and 7) ventricular changes (GLSSR and LSSR) in very low birth weight infants who develop BPD.

Role of strain imaging in right heart disease: a comprehensive review

Advances in the imaging techniques of the heart have fueled the interest in understanding of right heart pathology. Recently, speckle tracking echocardiography has shown to aid in understanding various right heart diseases and better management. Its role is well established in diagnosing right heart failure, pulmonary artery hypertension, arrhythmogenic right ventricular dysplasia and congenital heart disease. We review the basic mechanics of speckle tracking and analyze its role in various right heart conditions.

Advanced echocardiographic imaging of the congenitally malformed heart

There have been significant advancements in the ability of echocardiography to provide both morphological and functional information in children with congenitally malformed hearts. This progress has come through the development of improved technology such as matrix array probes and software which allows for the off line analysis of images to a high standard. This article focuses on these developments and discusses some newer concepts in advanced echocardiography such is multi-planar reformatting [MPR] and tissue motion annular displacement [TMAD].

Our aim is to discuss important aspects related to the quality and reproducibility of data, to review the most recent published data regarding advanced echocardiography in the malformed heart and to guide the reader to appropriate text for overcoming the technical challenges of using these methods. Many of the technical aspects of image acquisition and post processing have been discussed in recent reviews by the authors and we would urge readers to study these texts to gain a greater understanding [1]. The quality of the two dimensional image is paramount in both strain analysis and three dimensional echocardiography. An awareness of how to improve image quality is vital to acquiring accurate and usable data.

Three dimensional echocardiography (3DE) is an attempt to visualise the dynamic morphology of the heart. Although published media is the basis for theoretical knowledge of how to practically acquire images, electronic media [eg.www.3dechocardiography.com] is the only way of visualising the advantages of this technology in real time.

It is important to be aware of the limitations of this technology and that much of the data gleaned from using these methods is at a research stage and not yet in regular clinical practice.

Tissue Doppler, strain, and strain rate measurements assessed by two-dimensional speckle-tracking echocardiography in healthy newborns and infants

OBJECTIVES

To evaluate cardiac maturational and haemodynamic alteration in healthy newborns and infants and determine reference values in this period using tissue Doppler, strain, and strain rate echocardiography.

MATERIAL AND METHODS

The study included 149 healthy subjects. Babies from 1 day to 3 months were selected from the well-baby nursery department, and infants were selected from paediatric clinics during routine visits for health maintenance. Subjects were allocated to four groups: preterm (36-37 weeks, n = 32), term (≥ 38 weeks, n = 32), 1 month of age (n = 47), and 3 months of age (n = 38). Standard echocardiographic evaluations, pulsed wave Doppler, tissue Doppler echocardiography, strain, and strain rate studies were applied by the same person using a MyLab50 echo machine. Longitudinal and circumferential systolic strain and strain rate measurements were assessed by two-dimensional speckle-tracking echocardiography in all subjects.

RESULTS

The longitudinal systolic velocity, strain, and strain rate values derived from left ventricle apical four-, three-, and two-chamber images, and circumferential systolic velocity, strain, and strain rate values derived from left ventricle short-axis images decreased from the base to the apex in all subjects (p < 0.001).

CONCLUSION

Significant cardiac haemodynamic alterations occurred during the newborn and early infancy periods and were detected by tissue Doppler, strain, and strain rate echocardiography. Although two-dimensional speckle-tracking echocardiography is useful and can produce improved, reliable results in clinical practice, it has some limitations. Therefore, more studies on this issue are required.

Increased regional deformation of the left ventricle in normal children with increased body mass index: implications for future cardiovascular health

The prevalence of obesity continues to increase in the developing world. The effects of obesity on the cardiovascular system include changes in systolic and diastolic function. More recently obesity has been linked with impairment of longitudinal myocardial deformation properties in children. We sought to determine the effect of increased body mass index (BMI) on cardiac deformation in a group of children taking part in the population-based Southampton Women's Survey to detect early cardiovascular changes associated with increasing BMI before established obesity. Sixty-eight children at a mean age of 9.4 years old underwent assessment of longitudinal myocardial deformation in the basal septal segment of the left ventricle (LV) using two-dimensional speckle tracking echocardiography. Parameters of afterload and preload, which may influence deformation, were determined from cardiac magnetic resonance imaging. BMI was determined from the child's height and weight at the time of echocardiogram. Greater pediatric BMI was associated with greater longitudinal myocardial deformation or strain in the basal septal segment of the LV (β = 1.6, p < 0.001); however, this was not related to contractility or strain rate in this part of the heart (β = 0.001, p = 0.92). The end-diastolic volume of the LV increased with increasing BMI (β = 3.93, p < 0.01). In young children, regional deformation in the LV increases with increasing BMI, whilst normal contractility is maintained. This effect may be explained by the increased preload of the LV associated with increased somatic growth. The long-term implications of this altered physiology need to be followed-up.

Feasibility of a new image processing (4D Auto LVQ) to assessing right ventricular function in patients with chronic obstructive pulmonary disease

A new single-beat three-dimensional (3D) real time echocardiographic semi-automatic images processing (4D Auto LVQ) allows accurate assessment of left ventricular function, but whether it is suitable for the evaluation of right ventricular function remains unknown. To evaluate the feasibility of this procedure for assessing right ventricular volumes and function, right ventricular end-diastolic volumes (RVEDV), end-systolic volumes (RVESV) and ejection fraction (RVEF), stroke volumes (SV) and cardiac output (CO) were computed in 49 patients with chronic obstructive pulmonary disease (COPD) using 4D Auto LVQ. The myocardial performance index (MPI) was obtained by Doppler tissue imaging. The RV function parameters were compared with MPI by linear correlation analysis. A comparison of the performance of these RV function parameters in discrimination between MPI at a value of >0.45 or not was done. Compared with normal subjects, patients with COPD had significantly greater RVEDV, RVESV, MPI and significantly lower RVEF. Significant correlations were found between RVEF and MPI (r = -0.67, p < 0.001). The areas under the receiver operating characteristic curve for RVEF in discrimination between MPI at a value of >0.45 or not were 0.72, while they were 0.55 for SV and 0.57 for CO, respectively. The overall sensitivity, specificity and accuracy for RVEF analysis in predicting a >0.45 MPI in patients with COPD was 78.57%, 66.67% and 73.46%, respectively. These data suggest that 4D Auto LVQ is a feasible method for right ventricular volumes and function quantification in patients with COPD. Further studies are needed to improve the accuracy of the measurements.

Value of annular M-mode displacement vs tissue Doppler velocities to assess cardiac function in intrauterine growth restriction

OBJECTIVE

To compare the ability of two different methods for longitudinal annular motion measurement, M-mode and tissue Doppler imaging (TDI), to demonstrate cardiac dysfunction in intrauterine-growth-restricted (IUGR) fetuses.

METHODS

Cardiac longitudinal annular motion in the basal free wall of the left ventricle (mitral annulus), interventricular septum and tricuspid annulus was assessed in 23 early-onset IUGR cases and 43 controls by TDI (annular peak velocities) and M-mode (displacement).

RESULTS

All annular parameters were significantly decreased in the IUGR group with respect to controls using both methods. M-mode showed a trend towards equal performance as classifier between cases and controls, as compared to TDI, mainly in the tricuspid annulus.

CONCLUSIONS

Both M-mode and TDI demonstrate annular motion changes and consequently cardiac dysfunction in IUGR fetuses. M-mode imaging is simpler to perform and could be as sensitive as TDI for detecting subtle changes.

Left ventricular three-dimensional global systolic strain by real-time three-dimensional speckle-tracking in children: feasibility, reproducibility, maturational changes, and normal ranges

BACKGROUND

Three-dimensional (3D) strain analysis may help overcome the limitations of Doppler and two-dimensional strain analysis for the left ventricle and become the method of choice for left ventricular (LV) systolic function. The aims of this study were to evaluate the feasibility and reproducibility of LV global 3D systolic strain by real-time 3D speckle-tracking echocardiography (STE) in children and to establish their maturational growth patterns and normal values.

METHODS

A prospective study was conducted in 256 consecutive healthy subjects using real-time 3D echocardiography. Full-volume 3D data were acquired using a 3D matrix-array transducer. Three-dimensional LV peak systolic global strain (GS), global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS) values were determined using real-time 3D STE.

RESULTS

A total of 228 patients (89%) met the criteria for analysis; 28 (11%) were excluded. The correlations between age and strain variables by real-time 3D STE were poor (R(2) = 0.01-0.05, P < .05). The differences in GLS and GCS among the five age groups were statistically significant but clinically irrelevant. There were no statistical differences in GRS and GS values among the age groups, nor were there statistical differences between the genders for all 3D strain parameters. Intraobserver and interobserver variability ranged from 5.0 ± 4.3% to 10.1 ± 8.5% versus 6.9 ± 6.1% to 17.0 ± 16.2% for coefficients of variation, respectively. Interclass correlation coefficients ranged from 0.78 to 0.87 and from 0.75 to 0.79 for intraobserver and interobserver measurements for GS, GLS, GCS, and GRS, respectively.

CONCLUSIONS

LV global 3D systolic strain analysis using the new 3D STE is feasible and reproducible in the pediatric population. There are small maturational changes in GLS and GCS, but not in GRS and GS, that are statistically significant but probably clinically irrelevant. Further investigation is warranted for potential clinical application of this new technology in a pediatric population.

Acute changes in myocardial systolic function in preterm infants undergoing patent ductus arteriosus ligation: a tissue Doppler and myocardial deformation study

BACKGROUND

Ligation of a patent ductus arteriosus (PDA) in preterm infants causes profound hemodynamic changes that can result in low cardiac output syndrome and hypotension. The effect of PDA ligation on left ventricular myocardial function has not been studied using tissue Doppler and myocardial deformation imaging, mainly because of the limited validation of these methods in preterm infants. The primary objective of the present study was to determine the feasibility and reliability (intraobserver and interobserver variability) of tissue Doppler and myocardial deformation imaging for evaluating myocardial function in preterm infants undergoing surgical PDA ligation. Additionally, we sought to study the immediate effect of surgical ligation on the left ventricular tissue Doppler and strain measurements in the first 24 hours after surgery.

METHODS

Echocardiography was performed in 19 preterm infants before, 1 hour after, and 18 hours after PDA ligation born at 24-29 weeks of gestation. The tissue Doppler velocities of the lateral tricuspid and lateral and septal mitral valve annuli were obtained. The global and regional longitudinal peak systolic strain values were determined using two-dimensional speckle tracking echocardiography. The results of the three measurement points were compared using repeated measures analysis of variance. The intra- and interobserver variability was assessed using the intraclass correlation coefficient and Bland-Altman analysis.

RESULTS

The median gestational age was 25.0 weeks (interquartile range 24.9-25.9) and the birth weight was 750 g (interquartile range 600-810). For the global longitudinal strain, the intraobserver intraclass correlation coefficient was 0.92 (95% CI, 0.78-0.97, P < .001), and the interobserver intraclass correlation coefficient was 0.93 (95% CI, 0.66-0.98, P < .001). Bland-Altman analysis showed no significant bias between the two observers, with good agreement. The systolic and diastolic tissue Doppler velocities of the mitral valve decreased significantly immediately after ligation and remained significantly lower than the preoperative levels at 18 hours. Also, the global longitudinal strain values significantly decreased 1 hour after the procedure (global longitudinal strain before -19.7% ± -3.8% vs -11.5% ± -3.5%; P = .001) but had significantly improved 18 hours after the procedure (-15.1% ± -2.9%, P = .01).

CONCLUSIONS

The present study has shown the feasibility and reliability of using tissue Doppler and strain imaging in premature infants with a hemodynamically significant PDA. Significant changes in myocardial function were observed immediately after PDA ligation, suggesting important changes in myocardial performance immediately after ductal ligation.

Transthoracic echocardiography in children and young adults with congenital heart disease

Transthoracic echocardiography (TTE) is the first-line tool for diagnosis and followup of pediatric and young adult patients with congenital heart disease (CHD). Appropriate use of TTE can reduce the need for more invasive modalities, such as cardiac catheterization and cardiac magnetic resonance imaging. New echocardiographic techniques have emerged more recently: tissue Doppler imaging, tissue tracking (strain and strain rate), vector velocity imaging (VVI), myocardial performance index, myocardial acceleration during isovolumic acceleration (IVA), the ratio of systolic to diastolic duration (S/D ratio), and two dimensional measurements of systolic right ventricular (RV) function (e.g., tricuspid annular plane systolic excursion, TAPSE). These may become valuable indicators of ventricular performance, compliance, and disease progression. In addition, three-dimensional (3D) echocardiography when performed for the assessment of valvular function, device position, and ventricular volumes is being integrated into routine clinical care. In this paper, the potential use and limitations of these new echocardiographic techniques in patients with CHD are discussed. A particular focus is on the echocardiographic assessment of right ventricular (RV) function in conditions associated with increased right ventricular volume (e.g., pulmonary regurgitation after tetralogy of Fallot repair) or pressure (e.g., pulmonary hypertension) in children and young adults.

Imaging the right heart: the use of integrated multimodality imaging

During recent years, right ventricular (RV) structure and function have been found to be an important determinant of outcome in different cardiovascular and also pulmonary diseases. Currently, echocardiography and cardiac magnetic resonance (CMR) imaging are the two imaging modalities most commonly used to visualize the RV. Most structural abnormalities of the RV can be reliably described by echocardiography but due its complex geometrical shape, echocardiographic assessment of RV function is more challenging. Newer promising echocardiographic techniques are emerging but lack of validation and limited normal reference data influence their routine clinical application. Cardiac magnetic resonance is generally considered the clinical reference technique due to its unlimited imaging planes, superior image resolution, and three-dimensional volumetric rendering. The accuracy and reliability of CMR measurements make it the ideal tool for serial examinations of RV function. Multidetector computed tomography (MDCT) plays an important role in the diagnosis of pulmonary emboli but can also be used for assessing RV ischaemic disease or as an alternative for CMR if contra-indicated. Radionuclide techniques have become more obsolete in the current era. The different imaging modalities should be considered complimentary and each plays a role for different indications.

Non-Invasive Imaging for Congenital Heart Disease: Recent Innovations in Transthoracic Echocardiography

Transthoracic echocardiography (TTE) is an important tool for diagnosis and follow-up of patients with congenital heart disease (CHD). Appropriate use of TTE can reduce the need for more invasive and complex modalities, such as cardiac catheterization and cardiac magnetic resonance imaging. New echocardiographic techniques have emerged for the assessment of ventricular systolic and diastolic function: Tissue Doppler imaging, tissue tracking, strain and strain rate imaging, vector velocity imaging (VVI), myocardial performance index, myocardial acceleration during isovolumic contraction (IVA), the ratio of systolic to diastolic duration (S/D ratio), and other measurements of systolic right ventricular (RV) function like tricuspid annular plane systolic excursion (TAPSE). These modalities may become valuable indicators of ventricular performance, compliance and disease progression, with the caveat of preload-dependency of the variables measured. In addition, three-dimensional (3D) echocardiography for the assessment of cardiac anatomy, valvular function, device position, ventricular volumes and ejection fraction is integrated into routine clinical care. In this review, we discuss the potential use and limitations of these new echocardiographic techniques in patients with CHD. A particular focus is on the echocardiographic assessment of right ventricular (RV) function by means of tissue Doppler imaging, tissue tracking, and three-dimensional imaging, in conditions associated with increased right ventricular volume or pressure load.

The effect of adenotonsillectomy on right ventricle function and pulmonary artery pressure in children with adenotonsillar hypertrophy

OBJECTIVES

Adenotonsillar hypertrophy (ATH) is the most common cause of upper airway obstruction in children. Severe upper airway obstruction may have an effect on chronic alveolar hypoventilation, which consequently may lead to right ventricle (RV) dysfunction induced by hypoxemic pulmonary vasoconstriction. The investigators aimed to study RV function and mean pulmonary artery pressure (mPAP) in patients with ATH who were undergoing adenotonsillectomy by using tissue Doppler echocardiography (TDE).

METHODS

The study examined 27 children with ATH who had a mean age of 8 ± 2 years. The subjects were comprised 17 (63%) males and 10 (37%) females. Hypertrophy of the tonsils was graded according to the Brodsky scale. Children having either grade 3 or 4 hypertrophied adenotonsils were recruited for the study. Adenotonsillectomy was performed on all subjects in the study group and echocardiographic examination was repeated 3 months postoperatively.

RESULTS

Tricuspid Em significantly increased after adenotonsillectomy (17.7 ± 3.6 vs. 19.1 ± 5.5, p=0.04). The RV myocardial performance index (MPI) and mPAP significantly decreased after adenotonsillectomy (RV MPI: 0.57 ± 0.13 vs. 0.40 ± 0.12, p<0.001 and mPAP (mmHg): 31 ± 9 vs. 25 ± 7, p=0.001).

CONCLUSION

The results of this study, evaluated with the results of previous studies, demonstrated that adenotonsillectomy improved RV performance and reduced mPAP in children with ATH.

Monitoring in pediatric cardiac critical care: a worldwide perspective

Our ability to directly monitor the mechanisms that govern cellular function, oxygen use, and survival is minimal. Therefore, in critically ill children, surrogate markers are used to try to detect evolving or established hypoxia. These surrogate markers are best used in combination and are complementary to clinical examination. Regardless of resource limitations, we propose that the availability of certain monitoring tools form a standard of care without which pediatric cardiac critical care cannot be safely or optimally provided. These tools include standard invasive hemodynamic monitoring with electrocardiography, lactate measurement, central venous oxygen saturation, and echocardiography. Ultimately, monitoring is only useful when the clinician observes a specific value or trend and has the expertise to act appropriately.