Relationship between temporal sequence of right ventricular deformation and right ventricular performance in patients with corrected tetralogy of Fallot

Relationship between right and left ventricular diastolic dysfunction assessed by 2-dimensional speckle-tracking echocardiography in adults with repaired tetralogy of Fallot

Several studies have reported a correlation between right ventricular (RV) and left ventricular (LV) systolic dysfunction in adults with repaired tetralogy of Fallot (TOF). However, data are lacking regarding the relationship between RV and LV diastolic dysfunction assessed by 2-dimensional speckle-tracking echocardiography. We studied 69 adults with repaired TOF (mean age 34 years, 61% male) who had been regularly followed up and had routinely undergone echocardiography. In addition to conventional echocardiography, global longitudinal strain (GLS) and early diastolic strain rate (SRe) of both ventricles were assessed using 2-dimensional speckle-tracking echocardiography. Results were compared with 30 age- and sex-matched controls. RV and LV GLS were decreased in TOF patients compared with controls (− 18.4 ± 3.3% vs. −23.5 ± 4.2%, p < 0.001 and − 16.0 ± 3.8% vs. −20.0 ± 3.0%, p < 0.001, respectively). RV and LV SRe were also decreased in TOF patients compared with controls (1.22 ± 0.34 sec^− 1 vs. 1.47 ± 0.41 sec^− 1, p = 0.003 and 1.29 ± 0.42 sec^− 1 vs. 1.63 ± 0.42 sec^− 1, p < 0.001, respectively). A correlation between RV and LV SRe was found in TOF patients (r = 0.43, p < 0.001) as well as between RV and LV GLS (r = 0.45, p < 0.001). Two-dimensional speckle-tracking echocardiography reveals subclinical RV and LV diastolic dysfunction in adults with repaired TOF. A correlation is observed between RV and LV diastolic dysfunction as well as between RV and LV systolic dysfunction.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Tetralogy of Fallot: diagnosis to long-term follow-up

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect, affecting 3 in 10,000 live births. Surgical correction in early childhood is associated with good outcomes, but lifelong follow-up is necessary to identify the long-term sequelae that may occur. This article will cover the diagnosis of TOF in childhood, the objectives of surveillance through adulthood and the value of multi-modality imaging in identifying and guiding timely surgical and percutaneous interventions.

Relation of biventricular strain and dyssynchrony in repaired tetralogy of fallot measured by cardiac magnetic resonance to death and sustained ventricular tachycardia

Ventricular strain and dyssynchrony can be measured in patients with repaired tetralogy of Fallot (TOF), but their effect on clinical outcomes is poorly understood. The purpose of this study was to investigate if ventricular strain and dyssynchrony measured by cardiac magnetic resonance feature tracking are associated with death and sustained ventricular tachycardia. Patients with TOF who died or had ventricular tachycardia (TOF case, n = 16) were compared with age-matched patients with TOF with no adverse outcome (TOF control, n = 32). For each patient, midventricular short-axis and 4-chamber cine steady-state free precession images were analyzed using cardiac magnetic resonance feature-tracking software. Peak left ventricular (LV) and right ventricular (RV) global circumferential and longitudinal strain and indexes of dyssynchrony were compared between groups. Compared with the TOF control group, median strain values were significantly lower for the TOF case group for both the LV (circumferential: 17% vs 23%, p = 0.003; longitudinal: 13% vs 18%, p <0.001) and the RV (circumferential: 10% vs 16%, p = 0.001; longitudinal: 11% vs 18%, p <0.001). In a multivariate model including strain and dyssynchrony parameters, RV and LV longitudinal strain were strongly associated with the adverse outcome (p = 0.003 and 0.04, respectively; area under the curve = 0.92). No differences in ventricular dyssynchrony were identified between the groups. In conclusion, patients with TOF in this cohort who experienced adverse outcomes had lower values of all strain parameters than those who did not, and impaired longitudinal strain of both ventricles was strongly associated with adverse clinical outcomes.

Advanced echocardiographic imaging of the congenitally malformed heart

There have been significant advancements in the ability of echocardiography to provide both morphological and functional information in children with congenitally malformed hearts. This progress has come through the development of improved technology such as matrix array probes and software which allows for the off line analysis of images to a high standard. This article focuses on these developments and discusses some newer concepts in advanced echocardiography such is multi-planar reformatting [MPR] and tissue motion annular displacement [TMAD].

Our aim is to discuss important aspects related to the quality and reproducibility of data, to review the most recent published data regarding advanced echocardiography in the malformed heart and to guide the reader to appropriate text for overcoming the technical challenges of using these methods. Many of the technical aspects of image acquisition and post processing have been discussed in recent reviews by the authors and we would urge readers to study these texts to gain a greater understanding [1]. The quality of the two dimensional image is paramount in both strain analysis and three dimensional echocardiography. An awareness of how to improve image quality is vital to acquiring accurate and usable data.

Three dimensional echocardiography (3DE) is an attempt to visualise the dynamic morphology of the heart. Although published media is the basis for theoretical knowledge of how to practically acquire images, electronic media [eg.www.3dechocardiography.com] is the only way of visualising the advantages of this technology in real time.

It is important to be aware of the limitations of this technology and that much of the data gleaned from using these methods is at a research stage and not yet in regular clinical practice.

Normal ranges of right ventricular systolic and diastolic strain measures in children: a systematic review and meta-analysis

BACKGROUND

Establishment of the range of normal values and associated variations of two-dimensional (2D) speckle-tracking echocardiography (STE)-derived right ventricular (RV) strain is a prerequisite for its routine clinical application in children. The objectives of this study were to perform a meta-analysis of normal ranges of RV longitudinal strain measurements derived by 2D STE in children and to identify confounders that may contribute to differences in reported measures.

METHODS

A systematic review was conducted in PubMed, Embase, Scopus, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. Search hedges were created to cover the concepts of pediatrics, STE, and the right heart ventricle. Two investigators independently identified and included studies if they reported the 2D STE-derived RV strain measure RV peak global longitudinal strain, peak global longitudinal systolic strain rate, peak global longitudinal early diastolic strain rate, peak global longitudinal late diastolic strain rate, or segmental longitudinal strain at the apical, middle, and basal ventricular levels in healthy children. Quality and reporting of the studies were assessed. The weighted mean was estimated using random effects with 95% confidence intervals (CIs), heterogeneity was assessed using Cochran's Q statistic and the inconsistency index (I(2)), and publication bias was evaluated using funnel plots and Egger's test. Effects of demographic, clinical, equipment, and software variables were assessed in a metaregression.

RESULTS

The search identified 226 children from 10 studies. The reported normal mean values of peak global longitudinal strain among the studies varied from -20.80% to -34.10% (mean, -29.03%; 95% CI, -31.52% to -26.54%), peak global longitudinal systolic strain rate varied from -1.30 to -2.40 sec(-1) (mean, -1.88 sec(-1); 95% CI, -2.10 to -1.59 sec(-1)), peak global longitudinal early diastolic strain rate ranged from 1.7 to 2.69 sec(-1) (mean, 2.34 sec(-1); 95% CI, 2.00 to 2.67 sec(-1)), and peak global longitudinal late diastolic strain rate ranged from 1.00 to 1.30 sec(-1) (mean, 1.18 sec(-1); 95% CI, 1.04 to 1.33 sec(-1)). A significant base-to-apex segmental strain gradient (P < .05) was observed in the RV free wall. There was significant between-study heterogeneity and inconsistency (I(2) > 88% and P < .01 for each strain measure), which was not explained by age, gender, body surface area, heart rate, frame rate, tissue-tracking methodology, 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 = .59).

CONCLUSIONS

This study is the first to define normal values of 2D STE-derived RV strain in children on the basis of a meta-analysis. The normal mean value in children for RV global strain is -29.03% (95% CI, -31.52% to -26.54%). The normal mean value for RV global systolic strain rate is -1.88 sec(-1) (95% CI, -2.10 to -1.59 sec(-1)). RV segmental strain has a stable base-to-apex gradient that highlights the dominance of deep longitudinal layers of the right ventricle that are aligned base to apex. Variations among different normal ranges did not appear to be dependent on differences in demographic, clinical, or equipment parameters in this meta-analysis. All of the eligible studies used equipment and software from one manufacturer (GE Healthcare).

Feasibility and reproducibility of systolic right ventricular strain measurement by speckle-tracking echocardiography in premature infants

BACKGROUND

Right ventricular (RV) systolic function is an important prognostic determinant of cardiopulmonary pathologies in premature infants. Measurements of dominant RV longitudinal deformation are likely to provide a sensitive measure of RV function. An approach for image acquisition and postacquisition processing is needed for reliable and reproducible measurements of myocardial deformation by two-dimensional (2D) speckle-tracking echocardiography. The aims of this study were to determine the feasibility and reproducibility of 2D speckle-tracking echocardiographic measurement of RV peak global longitudinal strain (pGLS) and peak global longitudinal strain rate in premature infants and to establish methods for acquiring and analyzing strain.

METHODS

The study was designed in two phases: (1) a training phase to develop methods of image acquisition and postprocessing in a cohort of 30 premature infants (born at 28 ± 1 weeks) and (2) a study phase to prospectively test in a separate cohort of 50 premature infants (born at 27 ± 1 weeks) if the methods improved the feasibility and reproducibility of RV pGLS and peak global longitudinal strain rate measurements to a clinically significant level, assessed using Bland-Altman analysis (bias, limits of agreement, coefficient of variation, and intraclass correlation coefficient).

RESULTS

Strain imaging was feasible from 84% of the acquisitions using the methods developed for optimal speckle brightness and frame rate for RV-focused image acquisition. There was high intraobserver (bias, 3%; 95% limits of agreement, -1.6 to +1.6; coefficient of variation, 2.7%; intraclass correlation coefficient, 0.97; P = .02) and interobserver (bias, 7%; 95% limits of agreement, -4.8 to +4.73; coefficient of variation, 3.9%; intraclass correlation coefficient, 0.93; P < .05) reproducibility, with excellent linear correlation between the two pGLS measurements (r = 0.97 [P < .01] and r = 0.93 [P < .05], respectively).

CONCLUSIONS

This study demonstrates high clinical feasibility and reproducibility of RV pGLS and RV peak global longitudinal strain rate measurements by 2D speckle-tracking echocardiography in premature infants and offers methods for image acquisition and data analysis for systolic strain imaging that can provide a reliable assessment of global RV function.

Pulmonary Regurgitation after Tetralogy of Fallot Repair: A Diagnostic and Therapeutic Challenge

BACKGROUND

Pulmonary regurgitation is the key hemodynamically significant lesion in repaired tetralogy of Fallot contributing to progressive right ventricular (RV) dilatation and biventricular dysfunction. The timing for pulmonary valve replacement remains a controversial topic, and the decision to intervene depends on assessment of RV size and RV function.

OBJECTIVES

This review aims to discuss the echocardiographic techniques that can be used to assess patients with pulmonary regurgitation after the repair of tetralogy of Fallot defect. While cardiac magnetic resonance (CMR) imaging is the clinical reference method, there is an important role of echocardiography in identifying patients with significant pulmonary regurgitation and assessing the RV size and function. The different echocardiographic techniques that can be used in this context are discussed. Newer techniques for assessing RV size and function include three-dimensional (3D) echocardiography, tissue Doppler and strain imaging. 3D RV volumetric reconstruction based on two-dimensional imaging is a promising new technique that could potentially replace CMR for RV volumetric assessment.

CONCLUSIONS

Developments in echocardiographic techniques provide new insights into the impact of pulmonary regurgitation on RV structure and function. Echocardiography and CMR are complementary modalities and further research is required to define the optimal use of both techniques for this indication.