Strain and Strain Rate Measured on Echocardiogram 1-3 Weeks after Starting Treatment Is Worse in Acute Dilated Cardiomyopathy Pediatric Patients with Poor Outcomes at One Year

Normal Left Ventricular Systolic and Diastolic Strain Rate Values in Children Derived from Two-Dimensional Speckle-Tracking Echocardiography

BACKGROUND

Strain rate (SR) parameters derived from two-dimensional speckle-tracking echocardiography have prognostic value in children with heart disease. Routine use is hindered by a lack of normative data. The aim of this study was to determine reference values and Z scores for left ventricular systolic and diastolic SR in a large cohort of healthy children.

METHODS

Echocardiograms from 577 subjects ≤18 years of age (mean age, 9.6 ± 5.6 years; range, 1 day to 18.0 years; 46% female) with structurally and functionally normal hearts were retrospectively included. Left ventricular longitudinal and circumferential systolic and early and late diastolic SR were measured using two-dimensional speckle-tracking echocardiography from the apical four-chamber and short-axis mid-papillary views. Associations with age and body surface area were assessed using Spearman correlation and generalized additive modeling. The relationship between systolic SR and wall stress (afterload) was examined. Analyses were conducted with and without correction for heart rate. Multivariable linear regression modeling was used to identify independent factors associated with the SR parameters. Z score equations were derived from a selected best-fit parametric model.

RESULTS

All SR parameters differed significantly by age group. The magnitude of all SR values decreased with increasing age and body surface area. Systolic SR magnitude was inversely related to wall stress in children ≤7 years of age but not did not vary significantly in the older age groups. All relationships were maintained after heart rate correction. SR measurements had very good or excellent agreement.

CONCLUSION

Longitudinal and circumferential systolic and diastolic SR parameters are presented from a large cohort of healthy children using two-dimensional speckle-tracking echocardiography from the Philips platform. SR values differ significantly by age and body surface area. These results suggest that the myocardium becomes less sensitive to afterload with maturity. Z score equations based on age are presented, which should promote further clinical and research use.

Echocardiographic Measurements of Right Ventricular Mechanics in Infants with Bronchopulmonary Dysplasia at 36 Weeks Postmenstrual Age

OBJECTIVE

To test the hypothesis that specific echocardiographic measurements of right ventricular (RV) mechanics at 36 weeks postmenstrual age (PMA) are associated with the severity of bronchopulmonary dysplasia (BPD).

STUDY DESIGN

A subset of 93 preterm infants (born between 27 and 29 weeks of gestation) was selected retrospectively from a prospectively enrolled cohort. BPD was defined using the National Institutes of Health workshop definition, with modifications for oxygen reduction testing and altitude. The cohort was divided into no-BPD and BPD groups using previously published methodology for analyses. Echocardiographic measurements of RV function (ie, tricuspid annular plane systolic excursion, fractional area of change, systolic-to-diastolic ratio, tissue Doppler myocardial performance index, and RV strain), RV remodeling/morphology (end-systolic left ventricular eccentricity index), and RV afterload (pulmonary artery acceleration time measure) were evaluated at 36 weeks PMA. Multivariable logistic regression determined associations between RV measurements and BPD severity.

RESULTS

Compared with the no-BPD cohort, the BPD group had lower birth weight z-scores (P = .04) and trended toward a male predominance (P = .08). After adjusting for birth weight z-score, gestational age, and sex, there were no between-group differences in echocardiographic measurements except for the eccentricity index (scaled OR [0.1-unit increase], 1.49; 95% CI, 1.13-2.12; P = .01).

CONCLUSIONS

Among conventional and emerging echocardiographic measurements of RV mechanics, eccentricity index was the sole variable independently associated with BPD severity in this study. The eccentricity index may be a useful echocardiographic measurement for characterizing RV mechanics in patients with BPD at 36 weeks PMA.

Application of Neonatologist Performed Echocardiography in the Assessment and Management of Neonatal Heart Failure unrelated to Congenital Heart Disease

Neonatal heart failure (HF) is a progressive disease caused by cardiovascular and non-cardiovascular abnormalities. The most common cause of neonatal HF is structural congenital heart disease, while neonatal cardiomyopathy represents the most common cause of HF in infants with a structurally normal heart. Neonatal cardiomyopathy is a group of diseases manifesting with various morphological and functional phenotypes that affect the heart muscle and alter cardiac performance at, or soon after birth. The clinical presentation of neonates with cardiomyopathy is varied, as are the possible causes of the condition and the severity of disease presentation. Echocardiography is the selected method of choice for diagnostic evaluation, follow-up and analysis of treatment results for cardiomyopathies in neonates. Advances in neonatal echocardiography now permit a more comprehensive assessment of cardiac performance that could not be previously achieved with conventional imaging. In this review, we discuss the current and emerging echocardiographic techniques that aid in the correct diagnostic and pathophysiological assessment of some of the most common etiologies of HF that occur in neonates with a structurally normal heart and acquired cardiomyopathy and we provide recommendations for using these techniques to optimize the management of neonate with HF.