Tissue Doppler Imaging Measurement of Left Ventricular Systolic Function in Children: Mitral Annular Displacement Index Is Superior to Peak Velocity
ABSTRACT Doppler tissue imaging (DTI)-derived mitral annular systolic peak S-wave velocity (S') correlates with left ventricular (LV) ejection fraction (EF). The authors hypothesized that DTI mitral annular displacement, which is equal to the velocity-time integral of the DTI S' wave, might be superior to S' to analyze LV systolic function. Because S' varies with age, it was expressed as Sz, the z-score variance from normal S' for each subject. Because displacement varies with heart size, it was expressed as a displacement index, or the DTI S'-wave velocity-time integral divided by the end-diastolic distance from the mitral annulus to the LV apex. The aims of this study were to (1) measure the accuracy, sensitivity, specificity, and positive and negative predictive values of displacement index compared with Sz to detect systolic dysfunction; (2) compare displacement index with other quantitative parameters of longitudinal systolic function, including color DTI-derived strain and two-dimensional speckle-tracking echocardiography (2D)-derived mitral annular displacement and strain; and (3) determine the effects of age, heart rate (HR), and body surface area (BSA) on displacement index.
Displacement index and Sz results were compared with EF and with each other using statistical tests, including independent t tests, linear regression, receiver operating characteristic curve analysis, and 2 x 2 probability tables. Displacement index was also compared with other parameters of longitudinal systolic function, age, HR, and BSA using regression analysis.
Forty-six patients had normal (EF > or = 55%) and 34 abnormal (EF < 55%) LV function. Groups were statistically equivalent (P > .05) for age, HR, and BSA and statistically different (P < .001) for all measured parameters of systolic function. Displacement index and EF were linearly related. Receiver operating characteristic curve analysis showed the sensitivity of displacement index to be greater than that of Sz throughout the study range. Probability table analysis demonstrated that for predicting EF < 55%, the sensitivity, accuracy, and negative predictive value were greater for displacement index than for Sz. Displacement index was linearly correlated with 2D mitral annular longitudinal displacement, 2D LV basal segment longitudinal strain, and color DTI LV basal segment longitudinal strain. Displacement index was not affected by age, HR, or BSA.
Displacement index is linearly related to EF and also to other parameters of longitudinal systolic function. Displacement index has some advantages over Sz for assessing ventricular systolic function and should prove useful in measuring longitudinal and global LV systolic function.
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ABSTRACT: 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. To assess and compare serial echocardiographic indices of myocardial function in term and moderately preterm infants. 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). Primary: Systolic mitral and tricuspid annular plane excursions and annular peak systolic pulsed wave tissue Doppler (pwTDI) velocities. Secondary: Indices normalized for heart size. 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. 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.Early human development 04/2014; 90(7). DOI:10.1016/j.earlhumdev.2014.04.010 · 2.12 Impact Factor
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ABSTRACT: 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. Serial assessment of long-axis systolic atrioventricular annulus excursion in premature infants. 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. Systolic annulus excursion by grey-scale m-mode and colour tissue Doppler imaging (cTDI). 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%). 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 human development 09/2013; DOI:10.1016/j.earlhumdev.2013.09.006 · 2.12 Impact Factor
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ABSTRACT: 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 ResultsA 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. ConclusionZ-scores of Sm values were calculated and percentile charts were established to serve as reference data in patients with congenital heart diseases.Echocardiography 02/2014; 31(9). DOI:10.1111/echo.12541 · 1.26 Impact Factor