Effects of Frame Rate on Two‐Dimensional Speckle Tracking–Derived Measurements of Myocardial Deformation in Premature Infants

Abstract

BACKGROUND: Frame rate (FR) of image acquisition is an important determinant of the reliability of 2-dimensional speckle tracking echocardiography (2DSTE)-derived myocardial strain. Premature infants have relatively high heart rates (HR). The aim was to analyze the effects of varying FR on the reproducibility of 2DSTE-derived right ventricle (RV) and left ventricle (LV) longitudinal strain (LS) and strain rate (LSR) in premature infants. METHODS: RV and LV LS and LSR were measured by 2DSTE in the apical 4-chamber view in 20 premature infants (26 ± 1 weeks) with HR 163 ± 13 bpm. For each subject, 4 sets of cine-loops were acquired at FR of <90, 90-110, 110-130, and >130 frames/s. Two observers measured LS and LSR. Inter- and intra-observer reproducibility was assessed using Bland Altman analysis, coefficient of variation, and linear regression. RESULTS: Intra-observer reproducibility for RV and LV LS was higher at FR >110 frames/s, and optimum at FR >130 frames/s. The highest inter-observer reproducibility for RV and LV LS were at FR >130 and > 110 frames/s, respectively. The highest reproducibility for RV and LV systolic and early diastolic LSR was at FR > 110 frames/s. FR/HR ratio >0.7 frames/s/bpm yielded optimum reproducibility for RV and LV deformation imaging. CONCLUSIONS: The reliability of 2DSTE-derived RV and LV deformation imaging in premature infants is affected by the FR of image acquisition. Reproducibility is most robust when cine-loops are obtained with FR/HR ratio between 0.7 – 0.9 frames/s/bpm, which likely results from optimal myocardial speckle tracking and mechanical event timing.

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

“…Each eligible article meeting the inclusion criteria was reviewed by two independent reviewers (P.T.L and A.M.), and the following data was extracted and entered into an electronic database: (1) Study: first and last authors, year of publication; (2) demographic: number of controls subjects, age, gender; (3) Clinical: (heart rate (HR), body surface area (BSA) or body metabolic index (BMI); and (4) echocardiographic parameters: (vendor customized ultrasound and model , vendor customized software and version , probe frequency, frame rate, frame rate to heart rate ratio (FR/HR), 77 tissue tracking methodology, (endomyocardial, epicardium to endocardium), and reported location of the strain value along the stain curve (systolic strain, end systolic strain, or post-systolic strain). 74 All the authors of the eligible studies were contacted by electronic mail to notify them of the meta-analysis and obtain any missing information not reported in their individual studies.…”

Maturational Patterns of Systolic Ventricular Deformation Mechanics by Two-Dimensional Speckle-Tracking Echocardiography in Preterm Infants over the First Year of Age

“…19,20 At the Washington University School of Medicine site, a small proportion of the deformation data was previously used to test feasibility and reporducbility. 6,21 At the Royal College of Surgeons in Ireland site, deformation imaging by tissue Doppler has been assessed in the transitional period and up to 36 weeks post-menstrual age (PMA). 11,22 The institutional review board of Washington University and the ethical committee on human research at Royal College of Surgeons approved the protocol.…”

“…6,21 A frame rate to heart rate ratio (FR/HR) between 0.7 and 0.9 frames/sec per bpm was utilized to optimize myocardial speckle tracking and mechanical event timing. 21 LV global LS (LV GLS) and SRs (LV GLSRs) were calculated by averaging all values of the regional peak LS and SRs obtained from 17 segments in two-chamber, apical long-axis, and four- chamber apical views.…”

Ventricular Dysfunction, Interdependence, and Mechanical Dispersion in Newborn Infants with Congenital Diaphragmatic Hernia

“…Images with an optimised frame rate:heart rate ratio were selected for analysis [9]. The endocardial border was traced at end-systole to generate a region of interest, adjusted for optimal myocardial tracking.…”