Tissue Doppler Imaging Measurement of Left Ventricular Systolic Function in Children: Mitral Annular Displacement Index Is Superior to Peak Velocity

Association of high-sensitivity troponin T with left ventricular dysfunction in prediabetes

BACKGROUND

Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) are an increasingly serious problem worldwide. Tissue Doppler imaging (TDI), a non-invasive technique, may evaluate both systolic and diastolic function during the first phases of cardiovascular disease (CVD). High-sensitivity cardiac troponin T (hs-cTnT) can detect subclinical myocardial injury in asymptomatic prediabetic patients.

AIM

We aimed to investigate the relationship between left ventricular (LV) function and hs-cTnT in prediabetic patients.

METHODS

Between 1 October 2021 and 1 October 2022, we recruited 96 prediabetic and an equal number of age- and gender-matched healthy volunteers prospectively. TDI was used to evaluate both systolic and diastolic functions. Hs-cTnT levels were obtained and compared between groups.

RESULTS

It was found that the values for mitral annular plane systolic excursion (MAPSE), E, the rapid filling wave, E/Em, and the peak annular velocities of systolic excursion in the ejection period (Sm) were all significantly higher in these patients compared to healthy individuals (p < .001). Hs-cTnT was an independent predictor of left ventricular diastolic dysfunction (LVDD) and left ventricular systolic dysfunction (LVSD) (odds ratio [OR] = 2.625, 95% confidence interval [CI] = 1.324-4.308, p < .001, and OR = 1.922, 95% CI = 0.454-3.206, p = .004).

CONCLUSIONS

Prediabetics had higher hs-cTnT levels than controls. We showed that LVSD and LVDD functions were negatively affected in prediabetic patients. Our results proved that hs-cTnT levels may be associated with subclinical LV dysfunction in prediabetes.

Tricuspid annular plane systolic excursion and mitral annular plane systolic excursion cardiac reference values in 1300 healthy children: Single-center results

BACKGROUND

Tricuspid annular plane systolic excursion (TAPSE) and mitral annular plane systolic excursion (MAPSE) are two echocardiographic parameters which provide reliable information about the longitudinal myocardial functions of the right and left ventricles in both adult and pediatric population. The aim of this study was to determine the TAPSE and MAPSE reference values in healthy children aged 0-18 years.

METHODS AND RESULTS

This prospective study included 1300 healthy children evaluated with two-dimensional echocardiography. In addition to routine echocardiographic examination, the right and left ventricular systolic functions were assessed by TAPSE and MAPSE measurements. Statistical analyses were carried out in the groups of subjects stratified according to age and body surface area. The mean and standard deviation values and z-scores of TAPSE and MAPSE were developed in each group.

CONCLUSIONS

The determination of reference values for TAPSE and MAPSE in healthy children will be of guidance in the evaluation of both healthy children and those with congenital or acquired heart diseases in which the right and left ventricular systolic functions are affected. The reference values obtained will contribute to the clinical practice and the future studies.

Agreement between anatomical M-mode and tissue Doppler imaging in the assessment of fetal atrioventricular annular plane displacement in uncomplicated pregnancies: A prospective longitudinal study

AIM

To evaluate the level of agreement between M-mode and pulsed-wave tissue Doppler imaging (PW-TDI) techniques in assessing fetal mitral annular plane systolic excursion (MAPSE), tricuspid annular plane systolic excursion (TAPSE) and septal annular plane systolic excursion (SAPSE) in a low-risk population.

METHODS

This prospective longitudinal study included healthy fetuses assessed from 18 to 40 weeks of gestation. Tricuspid annular plane systolic excursion, MAPSE and SAPSE were measured using anatomical M-mode and PW-TDI. The agreement between the two diagnostic tests was assessed using Bland-Altman analysis.

RESULTS

Fifty fetuses were included in the final analysis. Mean values of TASPE were higher than that of MAPSE. There was a progressive increase of TAPSE, MAPSE and SAPSE values with advancing gestation. For each parameter assessed, there was an overall good agreement between the measurements obtained with M-mode and PW-TDI techniques. However, the measurements made with M-mode were slightly higher than those obtained with PW-TDI (mean differences: 0.03, 0.05 and 0.03 cm for TAPSE, MAPSE and SAPSE, respectively). When stratifying the analyses by gestational age, the mean values of TAPSE, MAPSE and SAPSE measured with M-Mode were higher compared to those obtained with PW-TDI, although the mean differences between the two techniques tended to narrow with increasing gestation. Tricuspid annular plane systolic excursion, MAPSE and SAPSE measurements were all significantly, positively associated with gestational age (all P < 0.001).

CONCLUSION

Fetal atrioventricular annular plane displacement can be assessed with M-mode technique, or with PW-TDI as the velocity-time integral of the myocardial systolic waveform. Atrioventricular annular plane displacement values obtained with M-mode technique are slightly higher than those obtained with PW-TDI.

Reference values for two-dimensional myocardial strain echocardiography of the left ventricle in healthy children

BACKGROUND

Myocardial deformation by speckle tracking echocardiography provides additional information on left ventricular function. Values of myocardial deformation (strain and strain rate) depend on the type of ultrasound machine and software that is used. Normative values for QLAB (Philips) are scarce, especially for children. It is important to evaluate the influence of age and body size on myocardial deformation parameters, since anthropometrics strongly influence many standard echocardiographic parameters. The aim of this study was to provide comprehensive normal values for myocardial deformation of the left ventricle using a Philips platform and to evaluate the association with anthropometric and standard echocardiographic parameters.

METHODS

Healthy children between 1 and 18 years of age were prospectively examined using a standard echocardiographic protocol. Short-axis and apical four-chamber, two-chamber, and three-chamber views were used to measure peak systolic circumferential and longitudinal strain and systolic and early diastolic strain rate of the left ventricle using dedicated software.

RESULTS

A total of 103 children were included with a mean age of 10.8 and inter-quartile range 7.3-14.3 years. Global circumferential strain values (±SD) were -24.2±3.5% at basal, -25.8±3.5% at papillary muscle, and -31.9±6.2% at apex levels. Global left ventricular longitudinal strain values were -20.6±2.6% in apical four-chamber view, -20.9±2.7% in apical two-chamber, and -21.0 ±2.7% in apical three-chamber. Age was associated with longitudinal strain, longitudinal systolic and early diastolic strain rate, but not with circumferential strain.

CONCLUSIONS

Normal values for left ventricular deformation parameters in children are obtained using a Philips platform. Age partly explains normal variation of strain and strain rate.

Association of High-Sensitivity Troponin T With Left Ventricular Dysfunction in Ankylosing Spondylitis

BACKGROUND

Ankylosing spondylitis (AS) is a systemic inflammatory disease, and cardiac dysfunction has not been clearly described clinically. High-sensitivity cardiac troponin T (hs-cTnT) is a noninvasive marker for subclinical myocardial injury.

OBJECTIVE

In this study, we aimed to investigate any relationship between hs-cTnT and left ventricular (LV) function evaluated via tissue Doppler imaging in AS patients with no known cardiac risk factor.

METHODS

Our study used a cross-sectional case protocol design and was conducted between January 2016 and June 2016. In total, 40 AS patients (17 females and 23 males) were age and sex matched with healthy volunteers (20 females and 20 males) and enlisted for this study. Detailed transthoracic echocardiography was performed, and tissue Doppler imaging was used to assess systolic and diastolic functions. High-sensitivity cardiac troponin T levels were measured and compared between 2 groups.

RESULTS

Compared with control subjects, AS patients had lower early (Em)/late (Am) diastolic myocardial velocities, mitral annular plane systolic excursion, and end-diastolic distance from the mitral annulus to the LV apex. Conversely, they had greater systolic myocardial velocity (Sm), isovolumetric relaxation time, and displacement index (p < 0.001, for all). Higher hs-cTnT levels were measured in AS patients (0.45 ± 0.22 vs. 1.11 ± 0.27, p < 0.001), and multivariate logistic regression analyses revealed that hs-cTnT was an independent predictor of LV diastolic dysfunction in AS patients.

CONCLUSIONS

These data show that AS patients had impaired LV functions and increased hs-cTnT levels. Tissue Doppler imaging may be a useful tool for detection of early functional LV abnormalities, and hs-cTnT may be valuable biomarker of diastolic LV dysfunction in AS patients.

Incremental Value of the Tissue Motion of Annular Displacement Derived From Speckle-Tracking Echocardiography for Differentiating Chronic Constrictive Pericarditis From Restrictive Cardiomyopathy

OBJECTIVES

The tissue motion of annular displacement provides an accurate and rapid assessment of left ventricular (LV) systolic function. However, it has rarely been used in patients with chronic constrictive pericarditis and restrictive cardiomyopathy. This study aimed to assess the differences in LV systolic function in patients with constrictive pericarditis and restrictive cardiomyopathy using tissue motion of annular displacement derived from speckle-tracking echocardiography.

METHODS

Twenty-four patients with constrictive pericarditis, 24 with restrictive cardiomyopathy, and 25 healthy volunteers (controls) were enrolled. The septal and lateral mitral annular longitudinal displacements, displacement at the midpoint, and normalized midpoint displacement of the mitral ring were calculated.

RESULTS

Mitral annular tracking and quantification of the tissue motion of annular displacement were achieved within 10 seconds. In patients with constrictive pericarditis, the lateral mitral annular longitudinal displacement, displacement at the midpoint, and midpoint displacement of the mitral ring were decreased, whereas the septal mitral annular longitudinal displacement was preserved compared to controls, indicating that the reduction of systolic function in constrictive pericarditis was caused by pericardial adhesion and calcium. In patients with restrictive cardiomyopathy, tissue motion of annular displacement was more reduced compared to patients with constrictive pericarditis and controls. The correlation between the septal mitral annular longitudinal displacement and left ventricular ejection fraction was 0.67 (P < .001). A cutoff value of 8.45 mm for the septal mitral annular longitudinal displacement could effectively differentiate constrictive pericarditis from restrictive cardiomyopathy with 95.2% sensitivity and 91.7% specificity.

CONCLUSIONS

The tissue motion of annular displacement was decreased in patients with constrictive pericarditis, which indicated early impairment of longitudinal function in constrictive pericarditis; adhesion and calcium in the pericardium might account for the reduction. The septal mitral annular longitudinal displacement provides a fast and effective method for the assessment of LV systolic function in patients with constrictive pericarditis and restrictive cardiomyopathy.

Acute and Long-Term Effects of LVAD Support on Right Ventricular Function in Children with Pediatric Pulsatile Ventricular Assist Devices

Right ventricular failure (RVF) is a significant issue when considering left ventricular assist device (LVAD) implantation in pediatrics. The aim of this study was to evaluate the effects of LVAD on right ventricular (RV) function in children. We retrospectively reviewed clinical and echocardiographic data of children who underwent Berlin Heart EXCOR LVAD focusing on RV function before and after implantation (1, 3, and 6 month follow-up). An isolated LVAD was used in 27 patients. Median age was 11 months (interquartile range [IQR]: 5-24 months), with a median weight of 6.3 kg (IQR: 5-9 kg). Median time on ventricular assist device (VAD) support was 147 days (IQR: 86-210 days). Twenty patients were successfully bridged to orthotopic heart transplantation (OHT) (74%), six patients died (22%), and also heart function recovered in one patient (4%). Before LVAD implantation, nine patients (33%) showed a RV fractional area change (RVFAC) less than or equal to 30%. After implantation, mean RVFAC increased up until the 3 month follow-up (43.13%; p = 0.033) and then slightly decreased. In a subgroup of 18 patients, the average strain value increased after the 1 month follow-up (p = 0.022). Right ventricular failure developed in 33% of patients before the 1 month follow-up, and 7.4% experienced RVF at the 6 month follow-up. No patient required biventricular assist device (BiVAD). In our population, pulsatile-flow LVAD in children allows optimal RV decompression and function post-LVAD as measured by improvement in RV function at echo particularly at 1 and 3 month follow-up. At long-term follow-up, the beneficial effects of LVAD on RV function seem to be reduced as signs and symptoms of late RVF may develop in some patients despite LVAD support.

Tissue Motion Annular Displacement of the Mitral Valve Can Be a Useful Index for the Evaluation of Left Ventricular Systolic Function by Echocardiography in Normal Children

As the important role of longitudinal shortening in ventricular function has been well recognized over the past decade, evaluation of longitudinal systolic function of the left ventricle has become a subject of growing interest. Tissue motion annular displacement of the mitral valve (TMAD) is a new parameter of longitudinal systolic function. Although some studies have reported that this new parameter correlates with left ventricular ejection fraction (LVEF) in adults, little is known about TMAD in normal children. In this work, we investigated 94 children with no history of cardiovascular disease. TMAD was measured in the apical four-chamber view using the two-dimensional speckle tracking technique. Three points for tracking were selected in a diastolic frame: the lateral mitral valve annulus, medial mitral valve annulus, and left ventricular apex. The value was expressed as the percentage of displacement of the midpoint of the mitral valve annulus, using software to correct for left ventricular length at end-diastole. Pearson's coefficient was used to estimate the correlation between TMAD and left ventricular systolic function parameters including the biplane modified Simpson method-derived ejection fraction and global longitudinal strain (GLS). We also analyzed the correlation between TMAD and heart rate (HR), height, age, and body surface area (BSA). TMAD was found to correlate significantly with LVEF (r = 0.71, p < 0.01) and GLS (r = -0.77, p < 0.01). However, no correlation was revealed for HR (r = -0.14, p = 0.19), height (r = -0.17, p = 0.10), age (r = -0.19, p = 0.09), or BSA (r = -0.19, p = 0.08). These results indicate that TMAD is useful for assessing LVEF and longitudinal systolic function in normal children, and is not influenced by changes in HR, height, age, or BSA.

Normative Data for Left and Right Ventricular Systolic Strain in Healthy Caucasian Italian Children by Two-Dimensional Speckle-Tracking Echocardiography

BACKGROUND

There is an increasing interest in echocardiographic strain (ε) measurements for the assessment of ventricular myocardial function in children; however, pediatric nomograms remain limited. Our aim was to establish pediatric nomograms for the left ventricular (LV) and the right ventricular (RV) ε measured by two-dimensional speckle-tracking echocardiography (2D-STE) in a large cohort of healthy children prospectively enrolled.

METHODS

Echocardiographic measurements included STE LV longitudinal and circumferential and RV longitudinal global end-systolic ε. Age, weight, height, heart rate (HR), and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement. Echocardiograms were performed by Philips-iE33 systems (Philips, Bothell, WA) and offline measurements on Philips-Q-Lab-9.

RESULTS

In all, 721 subjects (age 31 days to 17 years; 48% female) were studied. Low coefficients of determination (R²) were noted among all of the ε parameters evaluated and adjusted for age, weight, height, BSA, and HR (i.e., R² all ≤ 0.10; range, 0.01-0.088). This hampered the possibility of performing z-scores with a sufficient reliability. Thus, we are limited to presenting data as mean values (±SD) stratified for age groups and divided by gender. LV longitudinal ε values decreased with age (P < .001), while no significant age-related variations were noted for RV longitudinal ε. A significant base-to-apex (lowest to highest) gradient in circumferential LV ε values was noted at all ages (P < .001).

CONCLUSIONS

We report pediatric echocardiographic normative data for 2D-STE for the LV and RV ε by using vendor-specific software. Our results confirm previous observations, showing only little variations of strain parameters with age and gender.

Evaluation of left ventricular function in obese children without hypertension by a tissue Doppler imaging study

Background:

The prevalence of obesity is increasing worldwide. Obese children without hypertension are becoming an important health challenge.

Aims:

Complications of obesity in adults are well established, but in obese children, cardiac dysfunction has not been reported clinically.

Settings and Design:

The present crosssectional study investigates subclinical systolic and diastolic dysfunction using echocardiographic modalities.

Materials and Methods:

Twentyfive youngsters with body mass index (BMI) >30 and 25 healthy children with BMI <25 were assigned into case and control group, respectively. In all participants, complete cardiovascular examination, electrocardiography, and echocardiography were fulfilled. Echocardiography surveys included standard, pulsed wave Doppler (PWD), and tissue Doppler imaging (TDI).

Statistical Analysis Used:

SPSS software, version 24.

Results:

The two groups were matched for age and sex. The resting heart rate and blood pressure were markedly higher in the obese group (P = 0.0001) though they were within the normal range in either category. Ejection fraction in the two groups was similar. Left ventricular (LV) mass (P = 0.0001), LV mass index (P = 0.029), left atrialtoaortic diameter ratio (P = 0.0001), and LV enddiastolic diameter (P = 0.008) were significantly greater in the case group, indicating cardiomegaly and subclinical systolic and diastolic dysfunction. Except for the aortic velocity, all PWD variables were considerably lower in the case group, suggesting subclinical diastolic dysfunction. All TDI parameters varied significantly between the two categories. There was a direct correlation between isovolumetric relaxation time and BMI.

Conclusions:

Obesity in children without hypertension is associated with subclinical systolic and diastolic cardiac dysfunction. We propose the evaluation of blood pressure as well as myocardial performance using PWD and TDI in all obese children without hypertension, regularly.

Mitral annular plane systolic excursion/left ventricular length (MAPSE/L) as a simple index for assessing left ventricular longitudinal function in children

BACKGROUND

Assessment of longitudinal left ventricular (LV) function is important for early detection of cardiac dysfunction. Although mitral annular plane systolic excursion (MAPSE) obtained by M-mode echocardiography offers a simple method for assessing longitudinal LV function, normal values of MAPSE for children change according to body size.

METHODS

To minimize the effects of body size, MAPSE was divided by LV long-axis length (MAPSE/L). MAPSE/L was measured in 210 healthy children from birth to 15 years of age and classified into five subgroups. MAPSE/L was then compared with 10 parameters in 136 children (age, heart rate, mean blood pressure, ejection fraction of the LV (EF), peak atrial flow velocity/peak early diastolic flow velocity of mitral flow, tissue Doppler velocity during systole (s') and early diastole (e'), E/e' ratio, Tei index, and global longitudinal strain (GLS) of the LV by the speckle tracking method).

RESULTS

MAPSE/L was significantly lower in the neonate group than in the remaining four groups. MAPSE/L then increased with age to peak at 1-5 years and gradually decreased thereafter. In all cases beyond the neonatal period, MAPSE/L was more than 0.17. Among various parameters, GLS, age, EF, Tei index and s' were significantly associated with MAPSE/L in that order. In univariate analysis, GLS was most significantly associated with MAPSE/L (r=.56).

CONCLUSIONS

We have established normal reference values for MPSE/L in healthy children. MAPSE/L is expected to offer a simple parameter to evaluate LV longitudinal systolic function during daily routine echocardiography in children.

The role of very low birth weight and prematurity on cardiovascular disease risk and on kidney development in children: a pilot study

BACKGROUND

Cardiovascular and renal disease are nowadays among the leading cause of morbidity and mortality in Western Countries. Low birth weight has been recently considered a key factor in determining cardiovascular disease and long-term renal disease in adulthood.

METHODS

In our study we analyzed, through echocardiography, eco color Doppler of carotid arteries, ultrasound of abdominal aorta and kidneys, morphological characteristics of cardiovascular and renal system, in a group of children born preterm with very low birth weight, (birth weight<1500 grams) and in a group of children, age and sex matched, born at term with weight appropriate for gestational age. Fifteen children born very low birth weight preterm (cases), aged from 3 to 5 years, and 15, age and sex matched children, born appropriate for gestational age at term (controls) were enrolled in the study.

RESULTS

The two groups were homogeneous for interventricular septum diameter, left ventricular end-systolic diameter, left atrial diameter, and ejection fraction. Left ventricular end diastolic diameter was higher in case compared to controls (P=0.04), while aortic diameter root smaller (P=0.005). E and A waves peak velocities and E/A ratio resulted lower in cases compared to controls (P=0.02, P<0.001and P<0.001, respectively). Tei index, S, e' and a' waves velocities were similar in the two groups, while E/e' ratio was higher in cases (P=0.046). Intima-media thickness and antero-posterior diameter of abdominal aorta values did not differ in cases versus controls. Longitudinal diameters of both kidneys were reduced in cases compared to controls (P<0.05).

CONCLUSIONS

Although limited by the small sample size, our study highlighted an increased size of the left ventricle and altered left ventricular diastolic function in children born very low birth weight preterm, but no long-term consequences on systolic performance and vascular structure have been found. The finding of smaller kidneys in ex-preterm very low birth weight children could explain their higher susceptibility to develop renal disease in adulthood.

The mitral annular displacement by two-dimensional speckle tracking: a new tool in evaluating the left atrial function

BACKGROUND

The methods used to characterize the volume change and the deformation of the left atrium are highly dependent on technical factors and difficult to use in a clinical environment. The aim of this study was to demonstrate that mitral annular displacement by speckle tracking can be an alternative method to studying the longitudinal left atrial function.

METHODS

Ninety study participants (54% men), with a mean age of 53(±15) years, underwent a complete echocardiographic examination, comprising two-dimensional, three-dimensional and tissue Doppler imaging (TDI). They were divided into normal individuals (35) and patients having an abnormal echocardiography (55).

RESULTS

There was a very strong correlation between three-dimensional volumetric function and mitral annular displacement, both for the reservoir (r = 0.78; P < 0.0001) and contractile (r = 0.76; P < 0.0001) functions. The correlation with the longitudinal strain displayed an r = 0.87, P > 0.0001 for the reservoir and r = 0.81, P < 0.0001 for the contractile function. The systolic speed in pulsed TDI and the systolic displacement had an r = 0.83, P < 0.0001. Mitral annular displacement was a very good discriminator for normal versus abnormal participants [area under the curve (AUC) for reservoir = 0.872 and for contractile = 0.843; P < 0.0001], performing less well than three-dimensional (AUC reservoir = 0.892 and contractile = 0.915; P < 0.0001) or deformation (AUC = 0.921 and 0.903 respectively; P < 0.0001), but better than pulsed TDI (AUC = 0.807; P < 0.0001). The percentage error was ±15% for interobserver and ±12% for intraobserver variability. The time taken for displacement analysis was 9 ± 3 s for an experienced cardiologist and 12 ± 4 s for a beginner.

CONCLUSION

Mitral annular displacement by speckle tracking is a reliable and fast method to evaluate left atrial function. Given the strength of the correlations with strain parameters, it could be used as a surrogate measure of the deformation of left atrium.

Reference Ranges of Left Ventricular Strain Measures by Two-Dimensional Speckle-Tracking Echocardiography in Children: A Systematic Review and Meta-Analysis

BACKGROUND

Establishment of the range of reference values and associated variations of two-dimensional speckle-tracking echocardiography (2DSTE)-derived left ventricular (LV) strain is a prerequisite for its routine clinical adoption in pediatrics. The aims of this study were to perform a meta-analysis of normal ranges of LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) measurements derived by 2DSTE in children and to identify confounding factors that may contribute to variance in reported measures.

METHODS

A systematic review was launched in MEDLINE, Embase, Scopus, the Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Library. Search hedges were created to cover the concepts of pediatrics, STE, and left-heart ventricle. Two investigators independently identified and included studies if they reported 2DSTE-derived LV GLS, GCS, or GRS. The weighted mean was estimated by using random effects models with 95% CIs, heterogeneity was assessed using the Cochran Q statistic and the inconsistency index (I(2)), and publication bias was evaluated using the Egger test. Effects of demographic (age), clinical, and vendor variables were assessed in a metaregression.

RESULTS

The search identified 2,325 children from 43 data sets. The reported normal mean values of GLS among the studies varied from -16.7% to -23.6% (mean, -20.2%; 95% CI, -19.5% to -20.8%), GCS varied from -12.9% to -31.4% (mean, -22.3%; 95% CI, -19.9% to -24.6%), and GRS varied from 33.9% to 54.5% (mean, 45.2%; 95% CI, 38.3% to 51.7%). Twenty-six studies reported longitudinal strain only from the apical four-chamber view, with a mean of -20.4% (95% CI, -19.8% to -21.7%). Twenty-three studies reported circumferential strain (mean, -20.3%; 95% CI, -19.4% to -21.2%) and radial strain (mean, 46.7%; 95% CI, 42.3% to 51.1%) from the short-axis view at the midventricular level. A significant apex-to-base segmental longitudinal strain gradient (P < .01) was observed in the LV free wall. There was significant between-study heterogeneity and inconsistency (I(2) > 94% and P < .001 for each strain measure), which was not explained by age, gender, body surface area, blood pressure, heart rate, frame rate, frame rate/heart rate ratio, tissue-tracking methodology, location of reported strain value along the strain curve, ultrasound equipment, or software. The metaregression showed that these effects were not significant determinants of variations among normal ranges of strain values. There was no evidence of publication bias (P = .40).

CONCLUSIONS

This study defines reference values of 2DSTE-derived LV strain in children on the basis of a meta-analysis. In healthy children, mean LV GLS was -20.2% (95% CI, -19.5% to -20.8%), mean GCS was -22.3% (95% CI, -19.9% to -24.6%), and mean GRS was 45.2% (95% CI, 38.3% to 51.7%). LV segmental longitudinal strain has a stable apex-to-base gradient that is preserved throughout maturation. Although variations among different reference ranges in this meta-analysis were not dependent on differences in demographic, clinical, or vendor parameters, age- and vendor-specific referenced ranges were established as well.

Myocardial functional responses do not contribute to maximal exercise performance in the heat

BACKGROUND

Both the extent and means by which maximal oxygen uptake ([Formula: see text]) is depressed by elevated ambient temperature are uncertain. Particularly, information is currently unavailable regarding the possible influence of alterations in myocardial function on [Formula: see text] and performance during exercise in the heat. This study investigated the effects of environmental heat on [Formula: see text], peak work capacity, and myocardial function during a standard, progressive cycle test to exhaustion. Twelve euhydrated men (aged 20.7 ± 1.7 years) performed a maximal cycle test in an environmental chamber in both heat stress [35°C, 30% relative humidity (RH)] and temperate (20°C, 30% RH) conditions with measurement of standard gas exchange variables, core temperature, and echocardiographic measures of cardiac function.

RESULTS

A small but statistically significant reduction of peak work capacity was observed in the heat stress versus temperate conditions (253 ± 30 and 259 ± 30 W, respectively, p = 0.02). Mean [Formula: see text] was not statistically different in the two conditions (p = 0.16) but values were 3.4% lower in the heat, and 9 of 12 participants demonstrated lower values in the heat stress trial. No differences in responses of heart rate, cardiac output, stroke volume, core temperature, hydration status, or myocardial systolic or diastolic function were observed between the two conditions, but perceived body temperature was higher in the heat.

CONCLUSIONS

The small, negative impact of heat on exercise performance and [Formula: see text] could not be explained by disturbances in myocardial functional responses to exercise in young adult males.

Tissue motion annular displacement of the mitral valve using two-dimensional speckle tracking echocardiography predicts the left ventricular ejection fraction in normal children

BACKGROUND

The gold standard for determining the left ventricular ejection fraction is cardiac magnetic resonance imaging. Other parameters for determining the ejection fraction such as M-mode echocardiography are operator-dependant and often inaccurate. Assessment of the displacement of the mitral valve annulus using two-dimensional speckle tracking echocardiography may provide an accurate and simple method of determining the left ventricular ejection fraction in children.

METHOD

We retrospectively studied 70 healthy 9-year-old children with no history of cardiovascular disease who had been assessed using cardiac magnetic resonance imaging and two-dimensional transthoracic echocardiography. Mitral displacement was determined using the tissue motion annular displacement (TMAD) feature of Philips QLAB version 9. The midpoint displacement of the mitral valve was calculated, and the predicted left ventricular ejection fraction was compared with magnetic resonance imaging-derived and M-mode-derived ejection fractions.

RESULTS

The mean ejection fraction derived from magnetic resonance imaging (64.5 (4.6)) was similar to that derived from the TMAD midpoint (60.9 (2.7), p = 0.001) and the M-mode (61.9 (7), p = 0.012). The TMAD midpoint correlated strongly with the magnetic resonance imaging-derived ejection fraction (r = 0.69, p < 0.001), as did the predicted fraction (r = 0.67, p < 0.001). The M-mode ejection fraction showed a poor linear correlation with both magnetic resonance imaging-derived and TMAD-derived fractions (r = 0.33 and 0.04, respectively).

CONCLUSION

TMAD of the mitral valve is a simple, effective, and highly reproducible method of assessing the ejection fraction in normal children. It shows a strong linear correlation with magnetic resonance imaging-derived ejection fraction and is superior to M-mode-derived ejection fractions.

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.

Reference values of the mitral annular peak systolic velocity (Sm) in 690 healthy pediatric patients, calculation of Z-score values, and comparison to the mitral annular Plane systolic excursion (MAPSE)

BACKGROUND

The mitral annular peak systolic velocity (Sm) is an echocardiographic measurement using tissue Doppler imaging to assess longitudinal left ventricular (LV) systolic function in children and adults. We determined growth-related changes in Sm to establish reference values for the entire pediatric age group.

METHODS AND RESULTS

A prospective study was conducted in a group of 690 healthy pediatric patients (age: 1 day-18 years). We determined the effects of age, sex, and body surface area (BSA) on the Sm values. Regression analysis was used to estimate Sm from age, BSA, and sex. In addition, a correlation of normal Sm with normal age-matched values of the M-mode parameter mitral annular plane systolic excursion (MAPSE) was measured. The Sm ranged from a mean of 5.8 cm/sec (Z-score ±2: 3.6-8.0 cm/sec) in the newborn to 11.8 cm/sec (Z-score ±2: 8.5-15.1 cm/sec) in the 18-year-old adolescent. The Sm values showed a positive correlation with age and BSA with a nonlinear course. There was no significant difference in Sm values between females and males. A significant correlation was found between Sm and MAPSE values.

CONCLUSION

Z-scores of Sm values were calculated and percentile charts were established to serve as reference data in patients with congenital heart diseases.

Effect of antiepilepsy drug therapy on ventricular function in children with epilepsy: a tissue Doppler imaging study

Impaired cardiac myocardial function may contribute to the risk for sudden unexpected death of a patient with epilepsy. This study aimed to investigate the effect of antiepilepsy drugs (AEDs) on cardiac function in pediatric epileptic patients using standard and tissue Doppler imaging (TDI) echocardiography. This hospital-based, prospective cross-sectional study investigated 52 epileptic children (mean age 9.3 ± 3.1 years) treated with AEDs (duration 2.4-10.0 years) and 36 healthy children (mean age 9.5 ± 4.0 years). In the epilepsy group, standard echocardiography showed increased left ventricular (LV) end-diastolic and end-systolic diameters, an increased LV mass index, and preserved ejection fraction. The patients also exhibited increased mitral peak A-wave velocity and mitral E-wave deceleration time as well as a decreased mitral E/A ratio. The E/Em ratio was significantly higher in the epilepsy group (5.6 ± 1.2) than in the control group (5.2 ± 1.1) (p = 0.016). In the epilepsy group, TDI showed an increased isovolumetric relaxation time and myocardial performance index (MPI). It also exhibited decreased early diastolic velocity (Em) and a decreased mitral annular displacement index in these patients. There were positive correlations between the LV lateral wall MPI (r = 0.231), septal MPI (r = 0.223), and LV mass index (p < 0.05) but no correlation with the duration of AED treatment. The authors detected subclinical ventricular dysfunction associated with AEDs at a preclinical stage. They suggest that TDI can be useful for determining the short- and long-term cardiac effects of AEDs.

Longitudinal assessment of atrioventricular annulus excursion by grey-scale m-mode and colour tissue Doppler imaging in premature infants

BACKGROUND

There is a lack of standardized echocardiographic parameters to quantify ventricular function in newborn infants. Long-axis systolic ventricular shortening is a useful parameter of global ventricular function.

AIMS

Serial assessment of long-axis systolic atrioventricular annulus excursion in premature infants.

METHODS

Two-centre, prospective observational study. Fifty-seven premature infants (26 girls), median (range) gestational age 33(+5) (31(0)-34(+6)) weeks(+days), birth weight 1925 (1127-2836) grams were included. Echocardiographic examinations were performed at the first three days of life and at expected term.

OUTCOME MEASURES

Systolic annulus excursion by grey-scale m-mode and colour tissue Doppler imaging (cTDI).

RESULTS

A consistent longitudinal pattern was found for annulus excursion by grey-scale m-mode and cTDI. All parameters showed a pronounced increase at expected term (p < 0.001). After normalizing for ventricular size the increase at term was less pronounced. Results were lower by cTDI than by grey-scale m-mode for the left and right ventricular walls (p < 0.001). Intraobserver variability (range 1.5-9.8%) was lower than interobserver variability (5.5-18%).

CONCLUSIONS

Serial assessment of longitudinal ventricular shortening in premature infants by grey-scale m-mode and cTDI was feasible and the measurements displayed a consistent pattern. cTDI excursion measurements were lower and more dependent on image quality than m-mode measurements. Lower intraobserver variability suggests that repeated measurements should preferably be performed by the same observer. Annulus excursion varies with ventricular size and we suggest normalizing measurements by ventricular size.

Early subclinical left-ventricular dysfunction in obese nonhypertensive children: a tissue Doppler imaging study

A direct effect of obesity on myocardial function has not been not well established. Our aim was to investigate the effect of body mass index (BMI) and homeostatic model assessment of insulin resistance (HOMA-IR) on left-ventricular (LV) myocardial function in normotensive overweight and obese children by tissue Doppler imaging (TDI). We calculated the mitral annular displacement index (DI) and myocardial performance index (MPI) using TDI indices of systolic and diastolic LV function. In this hospital-based, prospective cross-sectional study, we studied 60 obese (mean age 13.2 ± 2.0 years) and 50 normal children. Subjects were divided into three groups: group 1 (BMI < 25, n = 50, control), group 2 (BMI 25-29.9 kg/m(2), n = 30, overweight), and group 3 (BMI ≥ 30 kg/m(2), n = 30, morbidly obese). Standard echocardiography showed increased LV diameters and LV mass/index and preserved ejection fraction in obese children. By TDI, LV systolic and diastolic function showed that peak late myocardial velocity (Em = 15.4 ± 2 cm/s), peak early myocardial velocity (Am = 8.7 ± 1.3 cm/s), Em/Am ratio (1.8 ± 0.3), isovolumetric relaxation time (IVRT = 59.2 ± 8.2 ms), MPI (0.39 ± 0.03), and DI (25.5 ± 3.2 %) of the lateral mitral annulus in the obese subgroups were significantly different from those of control subjects (18.2 ± 1.2 cm/sn, 6.9 ± 0.6 cm/sn, 2.6 ± 0.2, 51.2 ± 9.6 ms, 0.34 ± 0.03, and 33.13 ± 5.0 %, respectively; p < 0.001). These structural and functional abnormalities were significantly related to BMI. There were positive correlations between HOMA-IR, septal MPI, and LV mass. DI and MPI data indicated impaired subclinical LV function in all grades of isolated obesity at a preclinical stage. Insulin resistance and BMI correlated significantly with indices of LV function.

Mitral annular displacement by Doppler tissue imaging may identify coronary occlusion and predict mortality in patients with non-ST-elevation myocardial infarction

BACKGROUND

Mitral annular displacement (MAD) is a simple marker of left ventricular (LV) systolic function. The aim of this study was to test the hypothesis that MAD can distinguish patients with non-ST-segment elevation myocardial infarctions (NSTEMIs) from those with significant coronary artery disease without infarctions, identify coronary occlusion, and predict mortality in patients with NSTEMIs. MAD was compared with established indices of LV function.

METHODS

In this retrospective study, 167 patients with confirmed NSTEMIs were included at two Scandinavian centers. Forty patients with significant coronary artery disease but without myocardial infarctions were included as controls. Doppler tissue imaging was performed at the mitral level of the left ventricle in the three apical planes, and velocities were integrated over time to acquire MAD. LV ejection fraction, global longitudinal strain (GLS), and wall motion score index were assessed according to guidelines.

RESULTS

MAD and GLS could accurately distinguish patients with NSTEMIs from controls. During 48.6 ± 12.1 months of follow-up, 22 of 167 died (13%). MAD, LV ejection fraction, and GLS were reduced and wall motion score index was increased among those who died compared with those who survived (P < .001, P < .001, P < .001, and P = .02, respectively). Multivariate Cox proportional-hazards analyses revealed that MAD was an independent predictor of death (hazard ratio, 1.36; 95% confidence interval, 1.07-1.73; P = .01). MAD and GLS were reduced and wall motion score index was increased in patients with coronary artery occlusion compared with those without occlusion (P = .006, P = .001, and P = .02), while LV ejection fraction did not differ (P = .20).

CONCLUSIONS

MAD accurately identified patients with NSTEMIs, predicted mortality, and identified coronary occlusion in patients with NSTEMIs.

Myocardial function in offspring 5-8years after pregnancy complicated by preeclampsia

INTRODUCTION

Preeclampsia and diabetic pregnancies share pathophysiological features suggested to influence epigenetic changes during foetal life with importance for later development and metabolic and cardiovascular diseases.

AIM

Our objective was to study the myocardium in offspring after pregnancy complications.

METHODS

Forty-five children (age 5-8 years) delivered from pregnancies complicated by preeclampsia (n = 25), diabetes mellitus type 1 (n = 8) or gestational diabetes mellitus (n = 12) were included. Fifteen children from uneventful pregnancies served as controls. Myocardial functions of right and left ventricle were examined by conventional Doppler and tissue Doppler imaging (TDI).

RESULTS

No major differences were found in the myocardial function between offspring of pregnancy complications and control group. However, the preeclampsia group had smaller hearts, increased heart rate and increased late diastolic velocity (A'-wave) at mitral valve attachments shown by both pulsed wave and colour TDI compared to the control and diabetic groups together (p ≤ 0.01).

CONCLUSION

Children born after preeclampsia may show effects of a negative impact on the heart already at the age of 5 to 8 years. The numbers of examined children were, however, limited.

Time-of-day effect on cardiac responses to progressive exercise

This study was designed to examine time-of-day effects on markers of cardiac functional capacity during a standard progressive cycle exercise test. Fourteen healthy, untrained young males (mean ± SD: 17.9 ± 0.7 yrs of age) performed identical maximal cycle tests in the morning (08:00-11:00 h) and late afternoon (16:00-19:00 h) in random order. Cardiac variables were measured at rest, submaximal exercise, and maximal exercise by standard echocardiographic techniques. No differences in morning and afternoon testing values at rest or during exercise were observed for oxygen uptake, heart rate, cardiac output, or markers of systolic and diastolic myocardial function. Values at peak exercise for Vo(2) at morning and afternoon testing were 3.20 ± 0.49 and 3.24 ± 0.55 L min(-1), respectively, for heart rate 190 ± 11 and 188 ± 15 bpm, and for cardiac output 19.5 ± 2.8 and 19.8 ± 3.5 L min(-1). Coefficients of variation for morning and afternoon values for these variables were similar to those previously published for test-retest reproducibility. This study failed to demonstrate evidence for significant time-of-day variation in Vo(2)max or cardiac function during standard progressive exercise testing in adolescent males.

Myocardial function and aerobic fitness in adolescent females

A recent report indicated that variations in myocardial functional (systolic and diastolic) responses to exercise do not contribute to inter-individual differences in aerobic fitness (peak VO(2)) among young males. This study was designed to investigate the same question among adolescent females. Thirteen highly fit adolescent football (soccer) players (peak VO(2) 43.5 ± 3.4 ml kg(-1) min(-1)) and nine untrained girls (peak VO(2) 36.0 ± 5.1 ml kg(-1) min(-1)) matched for age underwent a progressive cycle exercise test to exhaustion. Cardiac variables were measured by standard echocardiographic techniques. Maximal stroke index was greater in the high-fit group (50 ± 5 vs. 41 ± 4 ml m(-2)), but no significant group differences were observed in maximal heart rate or arterial venous oxygen difference. Increases in markers of both systolic (ejection rate, tissue Doppler S') and diastolic (tissue Doppler E', mitral E velocity) myocardial functions at rest and during the acute bout of exercise were similar in the two groups. This study suggests that among healthy adolescent females, like young males, myocardial systolic and diastolic functional capacities do not contribute to inter-individual variability in physiologic aerobic fitness.

Rapid estimation of left ventricular function using echocardiographic speckle-tracking of mitral annular displacement

BACKGROUND

Left ventricular (LV) ejection fraction (EF) by transthoracic two-dimensional echocardiography is time-intensive and highly dependent on image quality. Mitral annular displacement (MAD) qualitatively correlates with EF and can be measured in patients with poor image quality and dropout. The authors hypothesized that speckle-tracking echocardiography (STE)-derived MAD could quantify EF accurately and tested this hypothesis using cardiac magnetic resonance (CMR) as a reference.

METHODS

One hundred eighteen patients undergoing clinical transthoracic echocardiography were screened, and 110 whose mitral annuli was sufficiently well-defined irrespective of LV endocardial visualization underwent CMR within 6 days (85 of 110 in 1 day). Reference CMR EF values were obtained using standard methodology. STE was used to track annular motion throughout the cardiac cycle in the apical 2-chamber and 4-chamber views. To establish the relationship between MAD and CMR EF and to obtain a formula to estimate EF from MAD, regression analysis was performed in a study group of 60 patients with a wide range of EFs. This formula was then used in an independent test group of 50 patients by comparing estimated MAD EF against CMR EF values using Pearson's correlation and Bland-Altman analyses.

RESULTS

In the study group, STE MAD correlated highly with CMR EF and resulted in a formula relating MAD to EF. In the test group, estimated EF correlated well with CMR EF (4-chamber, R(2) = 0.64; 2-chamber, R(2) = 0.55), with near-zero bias and acceptable limits of agreement. Intraobserver and interobserver variability were between 5.8% and 12.7%.

CONCLUSIONS

STE MAD is a clinically useful tool for quick, easy, robust, and accurate estimates of EF irrespective of LV endocardial definition.