Tissue Doppler Myocardial Velocity Imaging in Infants and Children-a Window into Developmental Changes of Myocardial Mechanics

Impact of Asthma Phenotypes on Myocardial Performance and Pulmonary Hypertension in Children and Adolescents With Moderate to Severe Persistent Asthma

BACKGROUND

Asthma is characterized by chronic inflammation and remodeling of pulmonary vessels and airway wall resulting in pulmonary hypertension (PH). Increased afterload on right ventricle (RV) myocardium leads to RV diastolic dysfunction (RVDD). Echocardiography is an excellent tool to detect these changes early. Using echocardiography, we assessed the impact of clinical asthma phenotypes on myocardial performance and PH in children with asthma.

MATERIALS AND METHODS

Sixty children with moderate or severe persistent asthma and 60 age and gender-matched healthy controls were enrolled. As per clinical phenotypes, children with asthma were classified into early wheezers (n = 30) and late wheezers (n = 30). Pulmonary function tests (PFT) and echocardiography, both conventional and pulse wave (PW), were performed.

RESULTS

Children with asthma had significant RVDD and higher incidence (33%) of PH. Myocardial performance index (MPI) was poor in asthmatics, 0.41 (0.04) compared to controls, 0.38 (0.03). Measures for PH such as tricuspid regurgitation (TR) gradient, TR velocity, and pulmonary artery pressure (PAP) were significantly higher in cases. Among clinical asthma phenotypes, there was no difference in left ventricular ejection fraction (LVEF) between early 64.3% (4.6) and late wheezers 65.6% (4.4). MPI was better in late wheezers at 0.41 (0.05) than in early wheezers at 0.40 (0.03). TR gradient, TR velocity, and PAP were significantly higher in early wheezers. The odds ratio for the development of PH was 0.74 (CI 0.25 - 2.17), and for the development of RVDD was 3.2 (CI 0.77 - 13.8), both in favor of early wheezers.

CONCLUSION

Children with asthma, particularly early-onset wheezers are at increased risk of developing PH and RVDD. We suggest annual screening by conventional echocardiography and pulse wave Doppler imaging for early diagnosis and timely initiation of management.

Umbilical cord serum insulin-like growth factor-1 levels of infants of diabetic mothers are correlated with diastolic dysfunction detected by tissue Doppler echocardiography

Tissue Doppler echocardiography (TDI) is a convenient method to detect cardiac dysfunction in the infants of diabetic mothers (IDMs). Umbilical cord serum insulin-like growth factor-1 (IGF-1) is known to be higher in IDMs. We aimed to determine whether there is a relation between diastolic functions examined by TDI and cord serum IGF-1 levels of IDMs. Cord serum IGF-1 levels of 32 IDMs and 22 healthy infants were measured. The cardiac functions of the infants were evaluated by M-Mode and TDI. For statistical analysis, Mann-Whitney U and Spearman correlation tests were used for continuous variables, and the chi-square test was used for categorical variables. The cord serum IGF-1 levels of the IDMs were higher (p = 0.000). The left ventricle (LV) e', LVa', LV e'/a', and LV Tei index, indicating left ventricular diastolic dysfunction in IDMs, were detected (LV e' p = 0.016; LV a' p = 0.003; LV e'/ a' p = 0.000; LV Tei index p = 0.023). IDMs' cord serum IGF-1 levels were found weakly correlated with the interventricular septum (IVS) and left ventricle posterior wall (LVPW) thicknesses in M-Mode and LV e' and LV e'/a' in TDI (IVS r = 0.357, p = 0.008; LVPW r = 0.289, p = 0.034; LV e' r = 0.297, p = 0.029; LV e'/ a' r = 0.031, p = 0.014).

CONCLUSION

To our knowledge, this is the first study to examine the relationship between cord serum IGF-1 levels and diastolic functions of IDMs assessed by TDI. A weak correlation was found between IGF-1 levels and IVS and LVPW thicknesses in M-Mode and LV e' and LV e'/a' parameters in TDI, revealing diastolic dysfunction in IDMs.

WHAT IS KNOWN

• The umbilical cord blood serum IGF-1 level of IDMs is higher than in infants of healthy mothers. • Diastolic dysfunction is a well-studied and frequently observed consequence in IDMs.

WHAT IS NEW

• This is the first study to examine the relationship between cord serum IGF-1 levels and diastolic functions of IDMs assessed by TDI. • A weak correlation was detected between the median cord serum IGF-1 level of IDMs and the median values of IVS, LVPW, LV e', LV a', LV e'/a' ratio.

A guide to echocardiographic assessment in children and adolescents with pulmonary hypertension

While the current definition of pulmonary hypertension (PH) is still based on haemodynamic variables, transthoracic echocardiography is the most important diagnostic clinical tool for the first assessment and evaluation of a patient, in whom PH is suspected. In addition, it is the most important clinical modality in long term follow-up and the utility of echocardiography has widely been demonstrated in patients with PH. Echocardiography not only reveals the underlying cardiac morphology and diagnosis of any associated cardiac defects. In most patients with PH right ventricular (RV) pressure estimation is feasible. In addition, ventricular systolic and diastolic function, as well as ventricular-ventricular interactions of both ventricles can be assessed by using echocardiography. Maximizing the use of echocardiography by reporting several measures to gain information and quantitatively describe the parameters, that are linked to prognosis, seem particularly appealing in these children, in whom other advanced imaging modalities requiring anaesthesia is associated with a considerable risk. Herein we provide a practical approach and a concise and clinically applicable echocardiographic guidance and present basic variables, which should be obtained at any assessment. Moreover, we present additional advanced echocardiographic measures, that can be applied in a research or clinical setting when progressive PH needs a deeper insight to assess heart function, estimation of pulmonary artery pressures among others, by echocardiography. Finally, clinically relevant studies in view of the prognostic properties with a focus on the most important echocardiographic variables in pediatric PH are summarized.

Dapagliflozin: a sodium-glucose cotransporter 2 inhibitor, attenuates angiotensin II-induced cardiac fibrotic remodeling by regulating TGFβ1/Smad signaling

BACKGROUND

Cardiac remodeling is one of the major risk factors for heart failure. In patients with type 2 diabetes, sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of the first hospitalization for heart failure, possibly through glucose-independent mechanisms in part, but the underlying mechanisms remain largely unknown. This study aimed to shed light on the efficacy of dapagliflozin in reducing cardiac remodeling and potential mechanisms.

METHODS

Sprague-Dawley (SD) rats, induced by chronic infusion of Angiotensin II (Ang II) at a dose of 520 ng/kg per minute for 4 weeks with ALZET® mini-osmotic pumps, were treated with either SGLT2 inhibitor dapagliflozin (DAPA) or vehicle alone. Echocardiography was performed to determine cardiac structure and function. Cardiac fibroblasts (CFs) were treated with Ang II (1 μM) with or without the indicated concentration (0.5, 1, 10 μM) of DAPA. The protein levels of collagen and TGF-β1/Smad signaling were measured along with body weight, and blood biochemical indexes.

RESULTS

DAPA pretreatment resulted in the amelioration of left ventricular dysfunction in Ang II-infused SD rats without affecting blood glucose and blood pressure. Myocardial hypertrophy, fibrosis and increased collagen synthesis caused by Ang II infusion were significantly inhibited by DAPA pretreatment. In vitro, DAPA inhibit the Ang II-induced collagen production of CFs. Immunoblot with heart tissue homogenates from chronic Ang II-infused rats revealed that DAPA inhibited the activation of TGF-β1/Smads signaling.

CONCLUSION

DAPA ameliorates Ang II-induced cardiac remodeling by regulating the TGF-β1/Smad signaling in a non-glucose-lowering dependent manner.

Echocardiography for the Assessment of Pulmonary Hypertension and Congenital Heart Disease in the Young

While invasive assessment of hemodynamics and testing of acute vasoreactivity in the catheterization laboratory is the gold standard for diagnosing pulmonary hypertension (PH) and pulmonary vascular disease (PVD) in children, transthoracic echocardiography (TTE) serves as the initial diagnostic tool. International guidelines suggest several key echocardiographic variables and indices for the screening studies when PH is suspected. However, due to the complex anatomy and special physiological considerations, these may not apply to patients with congenital heart disease (CHD). Misinterpretation of TTE variables can lead to delayed diagnosis and therapy, with fatal consequences, or–on the other hand-unnecessary invasive diagnostic procedures that have relevant risks, especially in the pediatric age group. We herein provide an overview of the echocardiographic workup of children and adolescents with PH with a special focus on children with CHD, such as ventricular/atrial septal defects, tetralogy of Fallot or univentricular physiology. In addition, we address the use of echocardiography as a tool to assess eligibility for exercise and sports, a major determinant of quality of life and outcome in patients with PH associated with CHD.

Retinoid X receptor agonists attenuates cardiomyopathy in streptozotocin-induced type 1 diabetes through LKB1-dependent anti-fibrosis effects

Diabetic cardiac fibrosis increases ventricular stiffness and facilitates the occurrence of diastolic dysfunction. Retinoid X receptor (RXR) plays an important role in cardiac development and has been implicated in cardiovascular diseases. In the present study, we investigated the effects of RXR agonist treatment on streptozotocin (STZ)-induced diabetic cardiomyopathy (DCM) and the underlying mechanism. Sprague-Dawley (SD) rats induced by STZ injection were treated with either RXR agonist bexarotene (Bex) or vehicle alone. Echocardiography was performed to determine cardiac structure and function. Cardiac fibroblasts (CFs) were treated with high glucose (HG) with or without the indicated concentration of Bex or the RXR ligand 9-cis-retinoic acid (9-cis-RA). The protein abundance levels were measured along with collagen, body weight (BW), blood biochemical indexes and transforming growth factor-β (TGF-β) levels. The effects of RXRα down-regulation by RXRα small interfering RNA (siRNA) were examined. The results showed that bexarotene treatment resulted in amelioration of left ventricular dysfunction by inhibiting cardiomyocyte apoptosis and myocardial fibrosis. Immunoblot with heart tissue homogenates from diabetic rats revealed that bexarotene activated liver kinase B1 (LKB1) signaling and inhibited p70 ribosomal protein S6 kinase (p70S6K). The increased collagen levels in the heart tissues of DCM rats were reduced by bexarotene treatment. Treatment of CFs with HG resulted in significantly reduced LKB1 activity and increased p70S6K activity. RXRα mediated the antagonism of 9-cis-RA on HG-induced LKB1/p70S6K activation changes in vitro. Our findings suggest that RXR agonist ameliorates STZ-induced DCM by inhibiting myocardial fibrosis via modulation of the LKB1/p70S6K signaling pathway. RXR agonists may serve as novel therapeutic agents for the treatment of DCM.

Myocardial functions, blood pressure changes, and arterial stiffness in children with severe hemophilia A

INTRODUCTION

Prolonging the life span of patients with hemophilia has led to the emergence of comorbidities. Cardiovascular diseases are one of the important causes of mortality in patients with hemophilia. This study investigated the myocardial functions, blood pressure changes, arterial stiffness, and risk factors associated with cardiovascular diseases in children with hemophilia.

MATERIAL AND METHODS

In total, 17 children with severe hemophilia A and 23 healthy children were included in the study. Myocardial functions were evaluated using standard and tissue Doppler echocardiography. Peripheral and central blood pressure measurements were performed, and arterial stiffness was evaluated. Carotid intima-media thicknesses (CIMT) serum glucose, insulin, insulin resistance index, and lipoprotein levels were measured.

RESULTS

There were no differences between the two groups in terms of age, and biochemical parameters (P > 0.05). The HDL-C levels in the hemophilia group were lower than those in the control group (P < 0.05). Five of the patients had insulin resistance (29.4%), whereas four had low HDL-C levels (23.5%). There were no differences between the groups in terms of the CIMT, peripheral blood pressure, and central systolic blood pressure (P > 0.05). In the hemophilia group, central diastolic blood pressure (cDBP), arterial stiffness, and myocardial performance index were higher (P < 0.05, P = 0.01, P < 0.01), whereas the ejection time was shorter than in the control group (P < 0.05).

CONCLUSIONS

Compared with the control group, there is an onset of arterial stiffness, cDBP values tend to increase, and serum HDL-C levels are lower in the hemophilia group. Moreover, myocardial systolic functions demonstrate a deterioration that becomes more prominent with the increase in arterial stiffness.

Assessment of lateral mitral, septal and tricuspid myocardial performance indices by tissue Doppler imaging in asthmatic children

INTRODUCTION

Recurrent hypoxia makes asthmatics at risk for pulmonary hypertension and ventricular dysfunction. Early stages of these cardiovascular diseases cannot be detected by conventional echocardiography. Tissue Doppler imaging has been introduced recently as a more sensitive and more accurate tool for investigating cardiovascular diseases.

OBJECTIVE

Investigating ventricular functions in asymptomatic asthmatic children using tissue Doppler echocardiography.

METHOD

Fifty asthmatic children and 50 controls were examined by conventional echocrdiography. Tissue Doppler echocardiography was performed to measure the myocardial performance (Tei) index at the lateral mitral, septal and tricuspid annuli.

RESULTS

Septal Tei indices among patients and uncontrolled asthmatics were significantly higher than healthy subjects and controlled asthmatics, respectively (P < 0.05). Septal and tricuspid Tei indices were significantly higher among severe asthmatics and patients with concomitant nasal allergy than those with mild asthma and those without concomitant nasal allergy, respectively (P < 0.05). Septal Tei index correlated negatively with daily inhaled corticosteroid dose (r = -0.412, P = 0.003) and forced expiratory volume in the 1st second/forced vital capacity (r = -0.877, P < 0.001). Lateral Tei index correlated positively with the patient age (r = 0.312, P = 0.027) and duration of asthma (r = 0.359, P = 0.011).

CONCLUSION

Tei index can detect subclinical ventricular dysfunction in asthmatics and is affected by asthma duration, control and severity. It can be used for future scoring of asthma severity. Septal annulus seems to be the best location for assessing Tei index in asthmatics.

Noninvasive Imaging in Adult Congenital Heart Disease

Multimodality cardiovascular imaging plays a central role in caring for patients with congenital heart disease (CHD). CHD clinicians and scientists are interested not only in cardiac morphology but also in the maladaptive ventricular responses and extracellular changes predisposing to adverse outcomes in this population. Expertise in the applications, strengths, and pitfalls of these cardiovascular imaging techniques as they relate to CHD is essential. The purpose of this article is to provide an overview of cardiovascular imaging in CHD. We focus on the role of 3 widely used noninvasive imaging techniques in CHD—echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography. Consideration is given to the common goals of cardiac imaging in CHD, including assessment of structural and residual heart disease before and after surgery, quantification of ventricular volume and function, stress imaging, shunt quantification, and tissue characterization. Extracardiac imaging is highlighted as an increasingly important aspect of CHD care.

Assessing Myocardial Function in Infants with Pulmonary Hypertension: The Role of Tissue Doppler Imaging and Tricuspid Annular Plane Systolic Excursion

Transthoracic echocardiography is the most common noninvasive method of evaluating pulmonary hypertension (PH) in infants. Identification of reliable, quantitative indices of myocardial function may enhance the diagnostic value of echocardiography in this population. We hypothesized that pulsed wave tissue Doppler imaging (TDI) and tricuspid annular plane systolic excursion (TAPSE) would be reproducible measurements and would suggest decreased ventricular function, in infants with PH. This retrospective case-control study involved subjects diagnosed clinically and echocardiographically with PH at <12 months of age, matched with controls by age and gestational age (GA). TAPSE was measured by M-mode in the apical 4-chamber view. TDI velocities were averaged from three consecutive cardiac cycles. Observers were blinded to patient identity and clinical status. Fifty-seven subjects, including 35 term or near-term infants ≥35 weeks GA [mean GA 39 weeks (±1.7), median age 1 day (range 0-2)] and 22 preterm infants [median GA 25.4 weeks (24.1-26.6), age 66 days (4-128)], were matched with 57 controls. Subjects with PH had lower TAPSE (term p < 0.001, preterm p = 0.03) and TAPSE indexed to body surface area (term p < 0.001, preterm p = 0.005). Mitral annular, septal, and tricuspid annular systolic (S') and early diastolic (E') TDI velocities were also decreased compared to controls (all p < 0.05). Intraclass correlation demonstrated 84-99% agreement between observers in measuring TDI and 92% for TAPSE. Intraobserver reliability for these measures was 98-99% and 96%, respectively. We concluded that TDI and TAPSE are reproducible indices of myocardial function and may serve as useful adjuncts to standard echocardiographic measures in infants with PH.

Right ventricular performance using myocardial deformation imaging in infants with bronchopulmonary dysplasia

OBJECTIVE

Right ventricular (RV) performance among infants with bronchopulmonary dysplasia (BPD) remains poorly understood. We tested the hypothesis that myocardial deformation imaging (MDI) strain and strain rate would allow for differentiation between infants with severe and milder forms of BPD, independent of tissue Doppler imaging (TDI) and superior to conventional echocardiographic measurements.

STUDY DESIGN

Infants with various severities of BPD (11 with none or mild, 13 with moderate and 10 with severe) underwent conventional echocardiography, TDI and MDI assessments at >36 weeks of corrected gestational age. BPD severity grading was determined according to the National Institutes of Child Health and Disease workshop rating scale by physicians blinded to the echocardiogram results. Group data were compared with one-way analysis of variance or Kruskal-Wallis tests, with post hoc multiple comparisons.

RESULTS

No differences in traditional echocardiographic parameters or TDI among the three BPD severity groups were observed; none of the infants had evidence of pulmonary hypertension. Using MDI, infants with severe BPD had lower peak global systolic strain than did infants with moderate BPD (P<0.01) or mild/none BPD (P<0.01). Early and late diastolic strain rate measurements were similar across the three groups.

CONCLUSIONS

Among infants with severe forms of BPD, evidence of abnormal RV systolic function was detected with MDI, but not traditional echocardiographic or TDI measurements. Infants with severe forms of BPD may represent a particularly high-risk subgroup for decreased RV performance warranting cardiac surveillance. MDI should be considered as a method to quantitate RV function in this population.

A comparison of echocardiographic variables of right ventricular function with exercise capacity after bosentan treatment in patients with pulmonary arterial hypertension: Results from a multicenter, prospective, cohort study

PURPOSE

Bosentan reduces pulmonary arterial pressure and improves exercise capacity in patients with pulmonary arterial hypertension (PAH). However, there are limited data regarding the extent to which the changes in echocardiographic variables reflect improvements in exercise capacity. We aimed to assess the improvement of echocardiographic variables and exercise capacity after 6 months of bosentan treatment for PAH.

METHODS

We performed a prospective study from June 2012 to June 2015 in seven participating medical centers. Echocardiography, including tissue Doppler imaging (TDI) and the 6-minute walk test distance (6MWD), was performed at baseline and after 6 months of bosentan treatment.

RESULTS

We analyzed 19 patients with PAH: seven with congenital shunt, six with collagen vascular disease, and six with idiopathic PAH. After bosentan treatment, mean 6MWD increased by 50 meters. Right ventricle (RV) systolic pressure, tricuspid annular plane systolic excursion, myocardial performance index (MPI) derived from TDI (MPI-TDI) of RV and left ventricle (LV), RV fractional area change, and RV ejection fraction were significantly improved. In particular, the magnitude of RV and LV MPI-TDI showed good correlation with changes in the 6MWD.

CONCLUSIONS

The magnitude of RV and LV MPI-TDI was strongly associated with improvements in exercise capacity. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:28-34, 2017.

Impaired right and left ventricular mechanics in adults with pulmonary hypertension and congenital shunts

AIMS

To assess left ventricle mechanics in Eisenmenger physiology patients with congenital shunts, and their relationship with the right ventricle, and to consider the clinical usefulness of this information.

METHODS

The study involved 28 patients with pulmonary artery hypertension (PAH) and congenital shunt, matched with 28 healthy participants. Standard echocardiography and pulsed wave tissue Doppler imaging were employed to analyze systolic and diastolic ventricular function, the myocardial performance index (MPI) of ventricles, and the strain and strain rate along the left ventricle lateral wall, septum, and right ventricle free wall.

RESULTS

The left ventricle ejection fraction was similar in the two groups. However, despite normal standard left ventricle measures, patients presented parameters of defective myocardial mechanics: mitral peak systolic velocity (S') (cm/s) (8.6 (7.6-10.9) vs. 10.7 (8.6-12.5); P = 0.002) was higher, whereas left ventricle-MPI was lower (0.54 ± 01 vs. 0.32 ± 0.07, P < 0.001). Right ventricle-MPI and right ventricle global strain were correlated significantly with left ventricle-MPI and left ventricle global strain (r = 0.74, P < 0.001; r = 0.442, P < 0.001, respectively). Clinically, the six-minute walking test results were correlated negatively with left ventricle-MPI (r = -0.69, P < 0.001), whereas the functional class was positively correlated (r = 0.36, P < 0.001). In conclusion, left ventricle mechanics and geometry are impaired in Eisenmenger syndrome patients, although conventional evaluation is in the normal range. Our results highlight the significance of ventricular interdependence in PAH and provide a useful tool for improving the clinical management of 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.

Myocardial Tissue Doppler Velocity in Child Growth

Background

In adults, tissue Doppler imaging (TDI) is a recommended component of routine echocardiography. However, TDI velocities are less accepted in pediatrics, due to their strong variability and age dependence in children. This study examines the distribution of myocardial tissue Doppler velocities in healthy children to assess the effect of age with cardiac growth on the various echocardiographic measurements.

Methods

Total 144 healthy children were enrolled in this study. They were recruited from the pediatric outpatient clinic for routine well-child visits. The statistical relationships between age and TDI values were analyzed. Also, the statistical relationships between body surface area (BSA) and TDI values, left ventricle end-diastolic dimension (LVEDD) and TDI values were analyzed. Also, we conducted multivariate analysis of cardiac growth parameters such as, age, BSA, LVEDD and TDI velocity data.

Results

All of the age, BSA, and LVEDD had positive correlations with deceleration time (DT), pressure half-time (PHT), peak early diastolic myocardial velocity, peak systolic myocardial velocity, and had negative correlations with peak late diastolic velocity (A) and the ratio of trans-mitral inflow velocity to early diastolic velocity of mitral annulus (E/E'). In the multivariate analysis, all of the age, BSA, and LVEDD had positive correlations with DT, PHT, and negative correlations with A and E/E'.

Conclusion

The cardiac growth parameters related alterations of E/E' may suggest that diastolic myocardial velocities are cardiac growth dependent, and diastolic function has positive correlation with cardiac growth in pediatric group. This cardiac growth related myocardial functional variation would be important for assessment of cardiac involvement either in healthy and sick child.

Determinants and Regression Equations for the Calculation of z Scores of Left Ventricular Tissue Doppler Longitudinal Indexes in a Healthy Italian Pediatric Population

Aim. We investigated the predictors of tissue Doppler left ventricular (LV) longitudinal indexes in a healthy Italian pediatric population and established normative data and regression equations for the calculation of z scores. Methods and Results. A total of 369 healthy subjects aged 1–17 years (age of 6.4 ± 1.1 years, 49.1% female) underwent echocardiography. LV peak longitudinal velocity at systole (s^'), early diastole (e^'), and late diastole (a^') was determined by tissue Doppler. The ratio of peak early diastolic LV filling velocity to e^' was calculated. Age was the only independent determinant of s^' (β = 0.491, p < 0.0001) and the strongest determinant of e^' (β = 0.334, p < 0.0001) and E/e^' (β = −0.369, p < 0.0001). Heart rate was the main determinant of a^' (β = 0.265, p < 0.0001). Male gender showed no effects except for a weak association with lateral s^', suggesting no need of gender-specific reference ranges. Age-specific reference ranges, regression equations, and scatterplots for the calculation of z scores were determined for each index. Conclusion. In a pediatric Italian population, age was the strongest determinant of LV longitudinal dynamics. The availability of age-specific normality data for the calculation of z scores may allow for correctly detecting LV dysfunction in pediatric pathological populations.

Diagnostic usefulness of quantitative tissue velocity imaging and anatomic M-mode echocardiography for coronary artery diseases: A pilot study

BACKGROUND AND OBJECTIVE

To explore the potential clinical usefulness and determine optimal diagnostic criteria of quantitative tissue velocity imaging and anatomic M-mode echocardiography in patients with coronary artery disease (CAD).

METHODS

We used quantitative tissue velocity imaging for the measurement of systolic myocardial velocity, and anatomic M-mode echocardiography for the measurement of ventricular wall-thickening fraction in 44 subjects with suspected CAD. Subjects were classified as patients if coronary angiography demonstrated a stenosis ≥ 50%, and as controls if it was strictly normal. The diagnostic criteria, sensitivity, and specificity were assessed by receiver-operator curves.

RESULTS

Controls had greater mean systolic myocardial velocity and ventricular wall-thickening fraction in the basal (6.59 ± 1.25 cm/s and 0.44 ± 0.05) and mid segment (5.23 ± 0.93 cm/s and 0.43 ± 0.04) than patients (5.02 ± 1.17 cm/s and 0.29 ± 0.04, 3.27 ± 1.29 cm/s and 0.29 ± 0.04, respectively, p < 0.001). Mid-segment ventricular wall-thickening fraction offered 95% sensitivity (95% CI 88.7% to 98.4%), and 98.3% specificity (95% CI 90.9% to 1.0) with an optimal cut-off point of 0.349, yielding better results than systolic myocardial velocity, which provided 83% sensitivity (95% CI 74.2% to 89.8%), 90% specificity (95% CI 79.5% to 96.2%), and optimal cut-off point 4.47. The combination of systolic myocardial velocity and ventricular wall-thickening fraction offered 97% sensitivity (95% CI 91.5% to 99.4%)

CONCLUSIONS

Mid-segment ventricular wall-thickening fraction might be suitable for the evaluation of patients with CAD.

Myocardial function in term and preterm infants. Influence of heart size, gestational age and postnatal maturation

BACKGROUND

Sparse knowledge exists on the differences in cardiac function between term and preterm infants. This study examines the impact of heart size, gestational age and postnatal maturation on myocardial function.

AIM

To assess and compare serial echocardiographic indices of myocardial function in term and moderately preterm infants.

METHODS

Longitudinal, prospective, observational echocardiographic cohort study of 45 healthy term infants examined at day three and at 12-20weeks postnatal age and 53 moderately preterm infants (gestational age 31-35weeks) examined at day three and at term equivalent (4-10weeks postnatal age).

OUTCOMES

Primary: Systolic mitral and tricuspid annular plane excursions and annular peak systolic pulsed wave tissue Doppler (pwTDI) velocities. Secondary: Indices normalized for heart size.

RESULTS

On day three, all indices were higher in the term than in the preterm infants whereas normalized systolic pwTDI velocities were lower in the term infants and normalized excursions showed no difference. All indices increased with advanced postnatal age. The indices in term infants on day three were lower than in preterm infants at term equivalent, with and without normalization. After postnatal maturation in both groups, all indices were higher in the term group (except left pwTDI), whereas normalized indices showed no consistent pattern.

CONCLUSIONS

Myocardial function indices increased with gestational age at birth and more profoundly with postnatal maturation. Serial examinations of non-normalized and normalized myocardial function indices showed no sustained differences between the preterm and the term infants. Normalization by heart size may be of value when assessing myocardial function in infants.

Speckle tracking echocardiography in very preterm infants: feasibility and reference values

BACKGROUND

Speckle tracking echocardiography (STE) applies computer software analysis on images generated by conventional ultrasound to define and follow a cluster of speckles from frame to frame and calculates parameters of motion (velocity, displacement) and deformation (strain, strain rate). We explored STE of the left ventricle in stable very preterm infants.

METHODS

Apical 4 chamber clips (4CH) and short axis clips (SAX) at the level of the papillary muscle were analyzed using TomTec software with manual tracing of cardiac borders. The software automatically segmented the ventricle into 6 equidistant segments and provided segmental and global analysis of deformation parameters. Tracking accuracy was scored visually.

RESULTS

Seventy-four clips from 51 infants with a median gestational age of 28weeks were analyzed. Feasibility of 4CH was 95.5% for longitudinal and 96.2% for radial parameters. The reliability of longitudinal and circumferential deformation parameters was good, but radial parameters were less reliable. 4CH mean (SD) global peak systolic longitudinal and radial strain (%) and strain rate (s(-1)) were -18.7(2.6), -1.73(0.28), 23.6(9.1) and 1.94(0.65), and SAX circumferential and radial strain and strain rate were -19.5(3.7), -1.97(0.46), 32.1(14.4) and 2.37(0.80).

CONCLUSION

STE is feasible in preterm infants. Optimal image acquisition is paramount. Longitudinal parameters in 4CH and circumferential in SAX were most robust.

Pediatric echocardiography: new developments and applications

In this Special Issue of the Journal, 6 review articles that represent the new developments and applications of echocardiography for diagnosis and assessment of congenital heart disease from fetus to adult are included. The goal is to provide an updated review of the evidence for the current and potential use of some of the new methodologies, i.e. fetal echocardiography, tissue Doppler imaging, strain imaging by speckle tracking imaging, ventricular synchrony, quantification using real time three-dimensional (3D) echocardiography, and 3D echocardiography for adults with congenital heart disease. We hope this effort will provide an impetus for more investigation and ultimately clinical application of these new methodologies to improve the care of those with congenital and acquired heart diseases in the pediatric population and beyond.