Two-dimensional speckle strain and dyssynchrony in single right ventricles versus normal right ventricles

Single ventricular strain measures correlate with peak oxygen consumption in children and adolescents with Fontan circulation

INTRODUCTION

Children with a single ventricle post-Fontan palliation are at increased risk of poor outcomes with peak oxygen consumption acting as a surrogate outcome marker. The purpose of this study is to evaluate the relationship between peak oxygen consumption and echocardiographic measures of ventricular function and deformation, including ventricular global longitudinal strain and dyssynchrony, in children and adolescents following Fontan palliation.

METHODS

Patients (age 8-21 years) with single ventricle post-Fontan palliation were prospectively recruited and participated in an echocardiogram, including views optimised for two-dimensional speckle tracking, and a cardiopulmonary exercise test on a cycle ergometer to maximal volitional fatigue.

RESULTS

Thirty-eight patients (mean age 13.7 ± 2.3 years) post-Fontan palliation had either a single left ventricular (n = 20), single right ventricular (n = 14), or biventricular (n = 4) morphology. Peak oxygen consumption (24.9 ± 5.6 ml/kg/minute) was correlated with global longitudinal strain (r = -0.435, p = 0.007), a strain discoordination time to peak index (r = -0.48, p = 0.003), and the presence of an electro-mechanical dyssynchrony strain pattern (p = 0.008). On multivariate regression modelling, these three variables were associated with peak oxygen consumption independently of age and sex. The single right ventricular group had evidence of possible diastolic dysfunction by E/e' compared to the single left ventricular and biventricular groups (p = 0.001).

CONCLUSIONS

Strain analysis measures are correlated with peak oxygen consumption in this cohort of children, adolescents, and young adults following Fontan palliation, suggesting that ventricular mechanics may influence the efficiency of the Fontan circulation.

Echocardiographic Strain to Predict Need for Transplant or Mortality in Fontan Patients with Hypoplastic Left Heart Syndrome

Despite recent advances, hypoplastic left heart syndrome (HLHS) patients subsequent to the Fontan still have significant morbidity and mortality. Some require heart transplant due to systemic ventricular dysfunction. Limited data exist on timing for transplant referral. This study aims to correlate systemic ventricular strain by echocardiography to transplant-free survival. HLHS patients who had Fontan palliation at our institution were included. Patients were divided into: 1) Required transplant or experienced mortality (composite end point); 2) Did not require transplant or survived. For those who experienced the composite endpoint, the last echocardiogram prior to the composite outcome was used, while for those who did not experience the composite endpoint the last echocardiogram obtained was used. Several qualitative and quantitative parameters were analyzed with focus on strain parameters. Ninety-five patients with HLHS Fontan palliation were identified. Sixty-six had adequate images and eight (12%) experienced transplant or mortality. These patients had greater myocardial performance index by flow Doppler (0.72 versus 0.53, p = 0.01), higher systolic/diastolic duration ratio (1.51 versus 1.13, p = 0.02), lower fractional area change (17.65 versus 33.99, p < 0.01), lower global longitudinal strain (GLS) (-8.63 versus - 17.99, p < 0.01), lower global longitudinal strain rate (GLSR) (- 0.51 versus - 0.93, p < 0.01), lower global circumferential strain (GCS) (-6.68 versus -18.25, p < 0.01), and lower (GCSR) global circumferential strain rate (-0.45 versus -1.01, p < 0.01). ROC analysis demonstrated predictive value for GLS - 7.6 (71% sensitive, 97% specific, AUC 81%), GLSR -0.58 (71% sensitive, 88% specific, AUC 82%), GCS - 10.0 (86% sensitive, 91% specific, AUC 82%), and GCSR -0.85 (100% sensitive, 71% specific, AUC 90%). GLS and GCS can help predict transplant-free survival in patients with hypoplastic left heart syndrome having undergone Fontan palliation. Higher strain values (closer to zero) may be a helpful tool in determining when transplant evaluation is warranted in these patients.

Global longitudinal strain analysis of the singe right ventricle: leveling the playing field

BACKGROUND

All available echocardiographic methods to assess single, systemic right ventricle (sRV) systolic function have limitations. Subjective grading is prone to bias and varies among readers. Quantitative methods that require significant manual input, such as fractional area change (FAC), are often not reproducible. The aim of this study is to determine whether global longitudinal strain (GLS) is more reproducible than FAC and subjective grading in sRV patients among individual readers and across different levels of experience.

METHODS

Clinically indicated echocardiograms for 40 patients with functional systemic right ventricles were assessed by 5 readers with varying reading experience: one sonographer, one cardiology fellow, and three attending cardiologists at different career stages. All readers were blinded to patient data and other reader responses. Each reader reviewed the same images for subjective grade (scale 1-8, normal to severely depressed), RV end-diastolic and end-systolic area measurements, and longitudinal strain analysis. A repeat analysis was performed under identical conditions after at least 2 weeks on all 40 patients. Inter- and intra-reader reproducibility was assessed with intraclass correlation coefficient (ICC). Correlations between responses were assessed with Spearman's correlation coefficient.

RESULTS

The subjective method had fair to good reproducibility (ICC 0.7, interquartile range (IQR) 0.60,0.72) while the FAC method was poor (ICC 0.46, IQR 0.39,0.51) between readers. Reproducibility for GLS was excellent (ICC 0.88, IQR 0.88,0.89). Intra-reader reproducibility was excellent by subjective grading (ICC 0.85, IQR 0.73,0.88), poor by FAC (ICC = 0.63, IQR 0.35,0.66) and excellent by GLS (ICC 0.93, IQR 0.88,0.96). Attending-level readers were more consistent with their subjective grading, while all readers were excellent with GLS.

CONCLUSION

GLS is more reproducible than conventional methods at assessing sRV systolic function between readers with different levels of experience. For most readers it was more consistent than their own subjective grade of RV function. Laboratories staffed by multiple readers are likely to be more consistent in grading systemic RV systolic function using GLS.

Investigating the Accuracy of Quantitative Echocardiographic-Modified Task Force Criteria for Arrhythmogenic Ventricular Cardiomyopathy in Adolescent Male Elite Athletes

Athlete preparticipation screening focuses on preventing sudden cardiac death (SCD) by detecting diseases such as arrhythmogenic ventricular cardiomyopathy (AVC), which affects primarily the right ventricular myocardium. Diagnosis may be obscured by physiological remodeling of the athlete heart. Healthy athletes may meet the 2010 Task Force Criteria right ventricular outflow tract (RVOT) dimension cut-offs, questioning the suitability of the modified Task Force Criteria (mTFC) in adolescent athletes. In this study, 67 male adolescent footballers undergoing preparticipation screening were reviewed. All athletes underwent a screening for resting ECG and echocardiogram according to the English FA protocol, as well as cardiopulmonary exercise testing, stress ECG, and exercise echocardiography. Athletes' right ventricular outflow tract (RVOT) that met the major AVC diagnostic criteria for dilatation were identified. Of 67 evaluated athletes, 7 had RVOT dilatation that met the major criteria, all in the long axis parasternal view measurement. All had normal right ventricular systolic function, including normal free-wall longitudinal strain (ranging from - 21.5 to - 32.7%). Left ventricular ejection fraction ranged from 52 to 67%, without evidence of structural changes. Resting ECGs and cardiopulmonary exercise tests were normal in all individuals. In a series of healthy athletes meeting the major AVC diagnostic criteria for RVOT dilatation, none had any other pathological changes on a detailed screening including ECG, exercise testing, and echocardiography. This report highlights that current AVC echocardiographic diagnosis criteria have limitations in this population.

Inter-observer and Inter-vendor Variability in Strain Measurements in Patients with Single Right Ventricular Anatomy

Myocardial strain offers new insights into ventricular performance, There are software packages from several different companies used to ascertain this, and little data is available in patients with single right ventricle (sRV) physiology. We aimed to compare the analysis of two strain software applications using a cohort of patients with sRV for both inter-vendor and inter-observer variability. Echocardiograms from 85 patients with sRV (122 separate studies) were prospectively evaluated. All had Glenn and/or Fontan palliation. Longitudinal 4-chamber (4LS), inflow/outflow (IO), circumferential, and radial strain were assessed using Velocity Vector Imaging (VVI, Seimens, Munich) and Automated Functional Imaging (AFI, General Electric, Boston) software. In a subset of 45 patients (61 separate studies), strain measurements were obtained by two sonographers so a paired "inter-observer" analysis could be performed. A moderate correlation between measurements made by the two systems was observed. Circumferential strain assessment had the highest R value (0.77) with all others having R values < 0.6. Both software packages showed modest inter-observer reproducibility for longitudinal and circumferential strain. VVI intraclass correlation coefficients (ICC) for 4LS and average circumferential strain (ACS) were 0.6 and 0.58, compared to 0.68 and 0.59 for AFI. Other than radial strain and VVI IO inferior strain, mean strain differences between AFI and VVI were ≤ 1%. Inter-observer variability is modest, however, mean differences are minimal suggesting reasonable clinical reliability. Inter-vendor variability is greater and not as clinically reliable. In patients with sRV, serial assessments with strain should be performed using the same software.

Longitudinal Assessment of Right Ventricular Function in Hypoplastic Left Heart Syndrome

Overall survival of patients with hypoplastic left heart syndrome (HLHS) has shown continued improvement. Right ventricular (RV) dysfunction, in the long term, adversely affects prognosis in these patients. This study examines changes in echocardiographic markers of RV function in a longitudinal cohort. We retrospectively reviewed patients with HLHS managed at our institution from 7/1994 to 1/2016. Follow-up included surgical and clinical data, and echocardiographic measures. Measures of RV function preceding and following all three stages of single ventricular palliation were collected. Freedom from transplant-free survival was assessed by Kaplan-Meier analysis. Multivariable associations with time to death or transplant were explored using the Cox proportional hazards model. A total of 120 patients with HLHS were identified. Norwood operation was performed in all patients. The probability of survival for the cohort was 71 ± 4.4%, 69 ± 4.5% and 66 ± 4.7% at 1, 2 and 5 years respectively after stage I Norwood operation. RV fractional area change (FAC), compared to post-Norwood was decreased at all subsequent stages with the greatest change noted post-superior cavo-pulmonary shunt from 40.7 ± 9.3% to 31.1 ± 8.3% (p < 0.001). Similarly, tricuspid valve annular systolic excursion (TAPSE) Z-score declined from -2.9 ± 1.3 to -9.7 ± 1.3 (p < 0.001) with a decrement at every stage of evaluation. In comparison to patients with post-Norwood RV FAC >35% and TAPSE Z-score > -5, patients with RV FAC  ≤ 35% and TAPSE Z-score  ≤ -5 had a significantly lower transplant-free survival (p < 0.0001). In patients with HLHS undergoing staged palliation, decrement in RV function manifests longitudinally. Post-Norwood RV FAC and TAPSE Z-score appear to be early markers of poor outcome in this population.

Ventricular function and dyssynchrony in children with a functional single right ventricle using real time three-dimensional echocardiography after fontan operation

BACKGROUND

This study aimed to evaluate the feasibility and clinical value of real time three-dimensional echocardiography (RT-3DE) for assessing ventricular systolic dysfunction and dyssynchrony in children with an functional single right ventricle (FSRV) having undergone the Fontan procedure.

METHODS

Twenty-five children with an FSRV and 25 healthy children were enrolled in our study. RV volume analysis was performed compared with magnetic resonance imaging (MRI) as the reference standard in FSRV patients. The patients were divided into wide and narrow QRS interval groups. Global and regional functions of the RV in three compartments (inflow, body, and outflow) were compared between FSRV and control subjects, including RV systolic dyssynchrony indices of maximal difference of time to minimal volume (Tmsv-Dif), standard deviation of time to minimal volume (Tmsv-SD), maximal difference of time to minimal volume corrected by R-R interval (Tmsv-Dif%), and standard deviation of time to minimal volume corrected by R-R interval (Tmsv-SD%).

RESULTS

RT-3DE measurements were significantly lower than MRI measurements for RV-EDV, RV-ESV, RV-SV, and RVEF (p < 0.01).Compared with controls, patients with an FRSV had significantly higher dyssynchrony indices and significantly lower global EF in both narrow QRS interval and wide QRS interval groups. Tmsv-SD% was shown to be most strongly correlated with MRI-RVEF (r = -.570, p = 0.003).

CONCLUSIONS

RT-3DE tended to underestimate RV ventricular volume in children with FSRV. Children with an FSRV and either a wide or narrow QRS interval had reduced ventricular function and higher dyssynchrony than normal subjects. Worsening RV dyssynchrony is associated with overall decline in function after the Fontan operation.

Single ventricle systolic function and cardiopulmonary exercise performance in adult patients with Fontan circulation

OBJECTIVE

We employed echocardiographic tissue characterization for the assessment of single ventricle systolic function and examined its relationship with cardiopulmonary exercise testing (CPET) performance in the Fontan circulation.

METHODS

40 consecutive adult Fontan patients (16 female, 24 male; mean age 26.3 ± 5.9) were enrolled in our prospective cross-sectional study. All patients underwent echocardiographic assessment including tissue characterization and CPET within 3 days from each other.

RESULTS

LAPSE (lateral annular plane systolic excursion) was higher in patients with a dominant left ventricle compared to a dominant right ventricle (12.3 + -2.6 vs 9.8 + -1.1 mm, p = .008) and in patients with AP (right atrium-pulmonary artery) connection than with lateral tunnel or extracardiac conduits (13.9 ± 1.7 vs 11.3 ± 2.6 and 10.9 ± 2.2 mm, p = .014 and p = .014, respectively). Maximal oxygen pulse (O₂ pulse max) was significantly higher in patients with a dominant left or common ventricle compared to patients with a dominant right ventricle (10.3 and 12.0 vs 6.6 ml/beat, p = .002 and p = .032, respectively). There was a positive correlation between O₂ pulse max and LAPSE (r = 0.442, p = .009), atrioventricular valve annulus systolic velocity (S') (r = 0.606, p < .0001), lateral wall basal segment systolic velocity (bas vel s) (r = 0.469, p = .009) and lateral wall mid segment systolic velocity (mid vel s) (r = 0.452, p = .012). In the multivariable regression model, S' (r = 0.606, p < .0001) remained predictive of O₂ pulse max.

CONCLUSIONS

LAPSE and S' are suitable parameters for the assessment of systolic function in Fontan patients. Subclinical systolic dysfunction of longitudinal fibers is associated with worse CPET performance. O₂ pulse max seems to be the best parameter reflecting Fontan patients' physical performance.

Velocity vector imaging for the assessment of segmental ventricular function in children with a single right ventricle after cavopulmonary anastomosis

OBJECTIVE

Ventricular function assessment is very important for the treatment and prognostic classification of children with a single right ventricle (SRV) after cavopulmonary anastomosis (CPA). However, unusual ventricular shapes can result in inaccurate measurements. The aim of this study was to evaluate velocity vector imaging (VVI) for assessing segmental ventricular function in children with SRV after CPA.

METHODS

Twenty-one children with SRV after CPA and 21 age- and sex-matched children with normal biventricular anatomy and function were included. The longitudinal velocity, displacement, strain and strain rate were measured in the two groups in six segments by VVI. The velocity, displacement, strain and strain rate of the SRVs were compared with max(dp/dt) measured during simultaneous cardiac catheterization in the SRV subjects.

RESULTS

The control group consisted of 13 males and 8 females (69% males) with a mean age of 6.7 ± 3.5 years and mean weight of 20.5 ± 6.5 kg, and the study group consisted of 13 males and 8 females with a mean age 6.7 ± 3.7 years and mean weight of 20.6 ± 6.8 kg. Age, weight and sex distribution were similar between the groups (all, p > .05). Strain and strain rate values in all six segments were significantly lower in the study group than in the control group (all, p < .05). The max(dp/dt) of the SRV was 522.84 ± 158.32 mmHg/s, and the strain rate of the basal segment at the rudimentary chamber correlated best with max(dp/dt) (r = 0.74, p < .01).

CONCLUSIONS

Segmental ventricular dysfunction was present in children with SRV after CPA, and it could be assessed using VVI.

Immediate Postnatal Ventricular Performance Is Associated with Mortality in Hypoplastic Left Heart Syndrome

Right ventricular (RV) function as assessed by deformation has been evaluated prenatally and after palliation in hypoplastic left heart syndrome (HLHS). However, limited data exist about the immediate postnatal cardiac adaptation and RV function in HLHS. We compared echocardiographic measures of cardiac performance in HLHS versus controls in their first week of life. As a secondary objective, we evaluated if markers at the first echocardiogram were associated with mid- and long-term outcomes. Clinical and echocardiographic data of patients with HLHS between 2013 and 2016 were reviewed. The study population was matched with controls whose echocardiograms were obtained due to murmur or rule out coarctation. Speckle-tracking echocardiography was used to assess deformation. Thirty-four patients with HLHS and 28 controls were analyzed. Age at echocardiogram was similar between HLHS and controls. The RV of HLHS was compared to both RV and left ventricle (LV) of controls. HLHS deformation parameters [RV peak global longitudinal strain (GLS), global longitudinal strain rate (GLSR)] and tricuspid annular plane systolic excursion (TAPSE) were decreased compared to RV of controls. The LV-fractional area change, peak GLS, GLSR, circumferential strain, and strain rate of controls were higher than the RV of HLHS. Calculated cardiac output (CO) was higher in the HLHS group (592 vs. 183 mL/kg/min, p = 0.0001) but similar to the combined LV and RV output of controls. Later mortality or cardiac transplantation was associated with the RV CO and RV stroke distance at initial echocardiogram. Cox proportional hazard regression determined that restriction at atrial septum, decreased initial RV stroke distance and decreased TAPSE had a higher risk of death or cardiac transplantation. TAPSE and RV stroke distance by velocity time integral had adequate inter-reader variability by Bland-Altman plot and Pearson's correlation. Our study found that the HLHS RV deformation is decreased in the early postnatal period when compared to both LV and RV of controls, but deformation was not associated with mid- and long-term outcomes. Later mortality or cardiac transplantation was associated with decreased initial stroke distance and cardiac output. Early evaluation of patients with HLHS should include an assessment of stroke distance and future research should evaluate its implication in management strategies.

Longitudinal Deformation of the Right Ventricle in Hypoplastic Left Heart Syndrome: A Comparative Study of 2D-Feature Tracking Magnetic Resonance Imaging and 2D-Speckle Tracking Echocardiography

In hypoplastic left heart syndrome (HLHS), long-term outcome is closely related to right ventricular function. Echocardiography and magnetic resonance imaging (MRI) are routinely used for functional assessment. MRI 2D-tissue feature tracking (2D-FT) allows quantification of myocardial deformation but has not yet been applied to HLHS patients. We sought to investigate the feasibility of this technique and to compare the results to 2D-speckle tracking echocardiography (2D-STE). In routine MRI 2D anatomical four chamber view, cine images were recorded in 55 HLHS patients (median age 4.9 years [1.6, 17.0]). Regional and global peak systolic longitudinal strain (LS) and strain rate (LSR) were determined using 2D-FT software. Echocardiographic four chamber view was analyzed with 2D-STE. Visualization of all myocardial segments with MRI was excellent, regional, and global LS and LSR could be assessed in all data sets. In 2D-STE, 28% of apical segments could not be analyzed due to poor image quality. Agreement of 2D-FT MRI and 2D-STE was acceptable for global LS, but poor for global LSR. In MRI, regional LS was lower in the septal segments, while LSR was not different between the segments. GLS and GLSR correlated with ejection fraction (GLS: r = - 0.45 and r < 0.001, GLSR: r = - 0.34 and p = 0.01). With new post-processing options, the assessment of regional and global LS and LSR is feasible in routine MRI of HLHS patients. For LS, results were comparable with 2D-STE. The agreement was poor for LSR, which might relate to differences in temporal resolution between the two imaging modalities.

Early Assessment of Right Ventricular Function in Systemic Lupus Erythematosus Patients using Strain and Strain Rate Imaging

Background

Right ventricular function is a crucial factor of the prognosis of systemic lupus erythematosus (SLE).

Objectives

To evaluate the right ventricular function in SLE patients with different degrees of pulmonary hypertension (PH) by strain and strain rate imaging.

Methods

A total of 102 SLE patients and 30 healthy volunteers were studied between October 2015 and May 2016. Patients were divided into three groups according to pulmonary artery systolic pressure (PASP) estimated by echocardiography: group control (A); PASP ≤ 30 mmHg (group B, n = 37); PASP 30-50 mmHg (mild PH; group C, n = 34); and PASP ≥ 50 mmHg (moderate-to-severe PH; group D, n = 31). Longitudinal peak systolic strain (ε) and strain rate (SR), including systolic strain rate (SRs), early diastolic strain rate (SRe) and late diastolic strain rate (SRa) were measured in the basal, middle and apical segments of the right ventricular free wall in participants by two-dimensional speckle tracking echocardiography (2D-STE) from the apical four-chamber view. A p < 0.05 was set for statistical significance.

Results

The parameters of ε, SRs, SRe, and SRa were significantly decreased in groups C and D compared with groups A and B. The ε of each segments was significantly lower in group D than in group C, while there were no differences in SRs, SRe and SRa between groups C and D.

Conclusions

Strain and strain rate imaging could early detect the right ventricular dysfunction in SLE patients with PH, and provide important value for clinical therapy and prognosis of these patients.

Frequent Activation Delay-Induced Mechanical Dyssynchrony and Dysfunction in the Systemic Right Ventricle

BACKGROUND

Patients with systemic right ventricles frequently experience progressive heart failure and conduction abnormalities leading to abnormal ventricular activation. Activation delay-induced mechanical dyssynchrony can contribute to ventricular failure and is identified by a classic strain pattern of paradoxical opposing wall motion that is an excellent predictor of response to cardiac resynchronization therapy in adults with left bundle branch block. The specific aims of this study were to compare right ventricular (RV) mechanics in an adult systemic right ventricle population versus control subjects, evaluate the feasibility of this RV strain pattern analysis, and determine the frequency of the classic pattern.

METHODS

Young adults (n = 25) with d-transposition of the great arteries, status post Mustard or Senning palliation (TGA-MS), were ambispectively enrolled and compared with healthy young adults (n = 30) who were prospectively enrolled. All subjects were imaged using novel three-apical view (18-segment) RV longitudinal speckle-tracking strain analysis (EchoPAC) and electrocardiographic data.

RESULTS

Patients with TGA-MS had diminished RV global peak systolic strain compared with control subjects (-12.0 ± 4.0% vs -23.3 ± 2.3%, P < .001). Most patients with TGA-MS had intrinsic or left ventricular paced right bundle branch block. A classic pattern was present in 11 of 25 subjects (44%), but this pattern would have been missed in four of 11 based only on the RV four-chamber (six-segment) model. Only three subjects underwent cardiac resynchronization therapy. Both subjects who had the classic pattern responded to cardiac resynchronization therapy, whereas the one nonresponder did not have the classic pattern.

CONCLUSION

Systemic right ventricles demonstrated decreased function and increased mechanical dyssynchrony. The classic pattern of activation delay-induced mechanical dyssynchrony was frequently seen in this TGA-MS population and associated with activation delays. This comprehensive RV approach demonstrated incremental value.

Early changes in right ventricular longitudinal function in chronic asymptomatic alcoholics revealed by two-dimensional speckle tracking echocardiography

BACKGROUND

Heart ventricular dysfunction has been characterized as reduced longitudinal function of the right ventricle (RV), and is associated with chronic alcohol abuse. This study investigated the use of two-dimensional speckle tracking echocardiography (2DSTE) to assess the longitudinal systolic and diastolic RV function of patients with alcoholic myocardial damage.

METHODS

We stratified 92 asymptomatic alcoholic men into three groups of increasing alcohol intake, Groups A-C. Thirty age-matched normal adult men served as the control group. Conventional echocardiography and tricuspid annulus peak systolic excursion (TAPSE) parameters were obtained. 2DSTE parameters were recorded from an apical 4-chamber view of the RV free wall. LV peak global longitudinal systolic strain was calculated from segmental averaging of the three apical long-axis views.

RESULTS

In Group C, the RV end diastolic diameter (RVEDD) was dramatically higher than that of Groups A, B and the control, while TAPSE was significantly lower in Group C compared with the other experimental groups. In Group B, the longitudinal early diastolic strain rate (SRe) and late diastolic strain rate (SRa) of the RV free wall, and LV longitudinal strain were significantly lower than that of Group A or the control. In Group C, all the 2DSTE parameters were significantly lower than that of the other groups. A significant negative linear correlation was noted between global RV systolic parameters systolic strain peak (S), peak systolic strain rate (SRs) and TAPSE (r1=-0.84, r2=-0.72, respectively, P <0.05).

CONCLUSIONS

Two-dimensional STE provided an effective and non-invasive method to assess the RV longitudinal function of patients with alcoholic myocardial damage. This methodology may be useful for diagnosing, directing treatment, and judging prognosis of alcoholic cardiac damage.

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.

Assessment of longitudinal systolic ventricular dysfunction and asynchrony using velocity vector imaging in children with a single right ventricle

Assessment of ventricular dysfunction and asynchrony is very important in predicting the outcome for children with a single right ventricle. However, the assessment is inaccurate and subjective because of the unusual ventricular shape. This study aimed to evaluate the feasibility and clinical value of velocity vector imaging for assessing longitudinal systolic ventricular dysfunction and intraventricular asynchrony in children with a single right ventricle. The study enrolled 36 children with a single right ventricle and 36 age-matched children with a normal heart. Peak systolic velocity, peak displacement, strain, strain rate, time to peak systolic velocity, and time to peak systolic strain were measured via velocity vector imaging using the Siemens Sequoia C512 echocardiography instrument. The maximum positive rate of ventricular pressure change (Max [dp/dt]) was obtained by cardiac catheterization for all the children with a single right ventricle. In the children with a single right ventricle, the maximal temporal differences and the standard deviations of the times to peak systolic velocity and peak systolic strain were higher (P < 0.01) than in the children with a normal heart. Moreover, the strain and strain rate values were significantly lower in all six segments (P < 0.05). The strain rate of the basal segment adjacent to the rudimentary chamber correlated best with Max (dp/dt) (r = 0.86; P < 0.01). Longitudinal systolic dysfunction and intraventricular asynchrony could be assessed accurately using velocity vector imaging in children with a single right ventricle.

Optimized multisite ventricular pacing in postoperative single-ventricle patients

Ventricular dyssynchrony is associated with morbidity and mortality after palliation of a single ventricle. The authors hypothesized that resynchronization with optimized temporary multisite pacing postoperatively would be safe, feasible, and effective. Pacing was assessed in the intensive care unit within the first 24 h after surgery. Two unipolar atrial pacing leads and four bipolar ventricular pacing leads were placed at standardized sites intraoperatively. Pacing was optimized to maximize mean arterial pressure. The protocol tested 11 combinations of the 4 different ventricular lead sites, 6 atrioventricular delays (50-150 ms), and 14 intraventricular delays. Optimal pacing settings were thus determined and ultimately compared in four configurations: bipolar, unipolar, single-site atrioventricular pacing, and intrinsic rhythm. Each patient was his or her own control, and all pacing comparisons were implemented in random sequence. Single-ventricle palliation was performed for 17 children ages 0-21 years. Pacing increased mean arterial pressure (MAP) versus intrinsic rhythm, with the following configurations: bipolar multisite pacing increased MAP by 2.2 % (67.7 ± 2.4 to 69.2 ± 2.4 mmHg; p = 0.013) and unipolar multisite pacing increased MAP by 2.8 % (67.7 ± 2.4 to 69.6 ± 2.7 mmHg; p = 0.002). Atrioventricular single-site pacing increased MAP by 2.1 % (67.7 ± 2.4 to 69.1 ± 2.5 mmHg: p = 0.02, insignificant difference under Bonferroni correction). The echocardiographic fractional area change in nine patients increased significantly only with unipolar pacing (32 ± 3.1 to 36 ± 4.2 %; p = 0.02). No study-related adverse events occurred. Multisite pacing optimization is safe and feasible in the early postoperative period after single-ventricle palliation, with improvements in mean arterial pressure and fractional area shortening. Further study to evaluate clinical benefits is required.

Two-dimensional global longitudinal strain rate is a preload independent index of systemic right ventricular contractility in hypoplastic left heart syndrome patients after Fontan operation

BACKGROUND

Assessment of systemic right ventricular (RV) function in patients with hypoplastic left heart syndrome is important during long-term follow-up after Fontan repair. Traditional echocardiographic parameters to evaluate systolic ventricular function are affected by loading conditions. The only generally accepted load-independent parameter of systolic function, end systolic elastance (Ees), requires invasive catheterization. Therefore, we sought to determine if parameters obtained by 2-dimensional speckle tracking (2DST) were affected by acute changes in preload and correlated with catheterization-derived indices of RV contractility in hypoplastic left heart syndrome patients after Fontan palliation.

METHODS AND RESULTS

Fifty-two patients with hypoplastic left heart syndrome (median age, 6.6; range 2.9-22.2 years) were prospectively enrolled to have echocardiography and conductance catheter studies performed simultaneously. We compared traditional echo, 2-dimensional speckle tracking and catheterization-derived parameters during different states of preload at baseline and during dobutamine infusion. Global longitudinal strain (S) showed a tendency to decrease with preload reduction, whereas global longitudinal strain rate (SR) did not change (S: -17.7 ± 3.4% versus -16.9 ± 3.8%, P=0.08; SR: -1.30 ± 0.29 versus -1.34 ± 0.34 s(-1), P=0.3). S did not change with dobutamine infusion (-17.7 ± 3.4% versus -18.4 ± 3.9%, P=0.24), whereas SR increased significantly (-1.30 ± 0.29 versus -2.26 ± 0.49 s(-1), P<0.001). RV Ees correlated with SR (rs= -0.47, P<0.001), but not with S (rs=0.07, P=0.5) or other echocardiographic parameters.

CONCLUSIONS

In contrast to S, SR was not affected by preload and correlated with Ees of the systemic RV. SR may be a useful noninvasive surrogate of RV contractility and suitable for follow-up of patients with hypoplastic left heart syndrome after Fontan palliation.

[Update on pediatric cardiology and congenital heart disease: imaging techniques, pulmonary arterial hypertension, hybrid treatment, and surgical treatment]

This article contains a review of the most significant contributions to pediatric cardiology and congenital heart disease reported in publications between September 2009 and August 2010. The review focuses on imaging techniques, new treatment for pulmonary arterial hypertension in pediatric patients, and therapy in general (e.g. hybrid treatment and surgical treatment). With regard to imaging techniques, the review highlights the increasing application of congenital heart disease diagnosis during fetal life, the introduction of new echocardiographic techniques (e.g. tissue Doppler imaging, two-dimensional speckle-tracking imaging and three-dimensional echocardiography) into routine clinical practice, and the growing use of cardiac CT and magnetic resonance imaging in diagnosis and the assessment of cardiac function, respectively. The role played by cardiac interventions continues to increase and cardiac surgery is becoming more advanced and has, in some cases, been combined with hybrid techniques. However, there are still a number of controversial issues in cardiac surgery that have not yet been resolved, such as whether or not fenestration should be used with Fontan surgery, the optimum type of correction for hypoplastic left heart syndrome, and the best conduit for pulmonary artery replacement.

New developments in paediatric cardiac functional ultrasound imaging

Ultrasound imaging can be used to estimate the morphology as well as the motion and deformation of tissues. If the interrogated tissue is actively deforming, this deformation is directly related to its function and quantification of this deformation is normally referred as 'strain imaging'. Tissue can also be deformed by applying an internal or external force and the resulting, induced deformation is a function of the mechanical tissue characteristics. In combination with the load applied, these strain maps can be used to estimate or reconstruct the mechanical properties of tissue. This technique was named 'elastography' by Ophir et al. in 1991. Elastography can be used for atherosclerotic plaque characterisation, while the contractility of the heart or skeletal muscles can be assessed with strain imaging. Rather than using the conventional video format (DICOM) image information, radio frequency (RF)-based ultrasound methods enable estimation of the deformation at higher resolution and with higher precision than commercial methods using Doppler (tissue Doppler imaging) or video image data (2D speckle tracking methods). However, the improvement in accuracy is mainly achieved when measuring strain along the ultrasound beam direction, so it has to be considered a 1D technique. Recently, this method has been extended to multiple directions and precision further improved by using spatial compounding of data acquired at multiple beam steered angles. Using similar techniques, the blood velocity and flow can be determined. RF-based techniques are also beneficial for automated segmentation of the ventricular cavities. In this paper, new developments in different techniques of quantifying cardiac function by strain imaging, automated segmentation, and methods of performing blood flow imaging are reviewed and their application in paediatric cardiology is discussed.

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).

Right ventricular mechanics using a novel comprehensive three-view echocardiographic strain analysis in a normal population

BACKGROUND

Although quantitative right ventricular (RV) strain analysis may be useful in congenital and acquired heart disease populations with RV failure, a comprehensive, standardized approach is lacking. An 18-segment RV strain analysis obtained from three standardized RV apical echocardiographic images was used to determine the feasibility, normal values, and reproducibility of the method in normal adults.

METHODS

Forty healthy, prospectively enrolled volunteers with no cardiac histories and normal QRS durations underwent echocardiography optimized for strain analysis including three RV apical views. Two-dimensional speckle-tracking longitudinal strain analysis was performed using EchoPAC software. Eleven retrospectively identified subjects with RV disease were included as a pilot population. All had been imaged using the same protocol including the three RV apical views.

RESULTS

All control subjects had normal anatomic morphology and function by echocardiography. Feasibility of the RV strain analysis was good (adequate tracking in 696 of 720 segments [97%]). RV global peak systolic strain was -23 ± 2%. Peak strain was highest in the RV free wall and lowest in the septum. Dyssynchrony indices demonstrated no dyssynchrony using left ventricular criteria. Reproducibility of most strain measures was acceptable. This methodology identified important disease not seen in the four-chamber apical view alone in the pilot population of 11 patients with RV disease. Strain patterns and values were different from those in the control population, indicating that differences do exist from normal.

CONCLUSIONS

Eighteen-segment RV strain analysis is feasible, with strain measures falling into discrete ranges in this normal population. Those with RV disease illustrate the potential utility of this approach. These data indicate that this model can be used for more detailed studies evaluating abnormal RV populations, in which its full potential can be assessed.

Reference intervals for the echocardiographic measurements of the right heart in children and adolescents: a systematic review

Background

Transthoracic echocardiography is the primary imaging modality for the diagnosis of right ventricular (RV) involvement in congenital and acquired heart diseases. There is increasing recognition of the contribution of RV dysfunction in heart diseases affecting children and adolescents, but there is insufficient information on reference intervals for the echocardiographic measurements of the right heart in children and adolescents that represent all the continental populations of the world.

Objective

The aim of this systematic review was to collate, from published studies, normative data for echocardiographic evaluation of the right heart in children and adolescents, and to identify gaps in knowledge in this field especially with respect to sub-Saharan Africans.

Methods

We performed a systematic literature search to identify studies of reference intervals for right heart measurements as determined by transthoracic echocardiography in healthy children and adolescents of school-going age. Articles were retrieved from electronic databases with a combination of search terms from the earliest date available until May 2013.

Results

Reference data were available for a broad range of variables. Fifty one studies out of 3096 publications were included. The sample sizes of the reference populations ranged from 13 to 2036 with ages varying from 5 to 21 years. We identified areas lacking sufficient reference data. These included reference data for determining right atrial size, tricuspid valve area, RV dimensions and areas, the RV % fractional area change, pulmonary artery pressure gradients and the right-sided haemodynamics, including the inferior vena cava dimensions and collapsibility. There were no data for sub-Saharan African children and adolescents.

Conclusion

Reliable reference data are lacking for important echocardiographic measurements of the RV in children and adolescents, especially for sub-Saharan Africans.

Insights into the evolution of myocardial dysfunction in the functionally single right ventricle between staged palliations using speckle-tracking echocardiography

BACKGROUND

The long-term prognosis of hypoplastic left heart syndrome is limited by progressive right ventricular dysfunction. The aim of this study was to determine the trends in single right ventricular systolic function between staged palliative surgeries using speckle-tracking and conventional echocardiography.

METHODS

There were 76 patients with functionally single right ventricles at the (1) pre-Norwood (n = 26), (2) pre-bidirectional cavopulmonary anastomosis (BCPA; n = 19), (3) pre-Fontan (n = 16), and (4) post-Fontan (n = 15) stages, compared with 30 controls of similar ages. Speckle-tracking-derived longitudinal and circumferential strain and strain rate, postsystolic strain index, and mechanical dyssynchrony index were compared with conventional measures of ventricular function. Differences between stages were analyzed using analysis of variance (P < .05).

RESULTS

Strain rate was highest at the pre-Norwood stage and decreased at the other stages (longitudinal P < .0001, circumferential P = .0002), as opposed to controls, in whom strain rate was maintained. Longitudinal strain was significantly decreased at the pre-BCPA stage compared with the pre-Norwood stage (P = .004), but circumferential strain was maintained, resulting in a corresponding decrease in the ratio of longitudinal to circumferential strain, which failed to resemble that of controls. Longitudinal (P = .003) and circumferential (P = .002) postsystolic strain indices were greatest at the pre-BCPA stage.

CONCLUSIONS

A decline in contractility occurred at the pre-BCPA stage. Although there was evidence of adaptation of the single right ventricle, this failed to resemble the normal left ventricle and may be insufficient to handle the chronic volume load or insult from previous surgery. These findings suggest an intrinsic inability of the single right ventricular myocardium to fully adapt to chronic systemic pressures.

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.

Decreased right ventricular function in healthy pediatric cystic fibrosis patients versus non-cystic fibrosis patients

Right ventricular (RV) dysfunction may occur in patients with cystic fibrosis (CF). Tissue Doppler imaging (TDI) and strain and strain rate analysis are new echocardiographic tools that can quantitate RV function. This study aimed to compare the RV function between healthy CF patients and non-CF patients to determine whether differences exist. Healthy CF children and age-matched non-CF children were enrolled in the study. In this study, TDI analysis of the RV free wall was performed at the level of the tricuspid valve annulus. Two-dimensional speckle echocardiography was used to measure global strain and strain rates in a six-segment model of the RV. Independent t tests were used to compare the groups. The study enrolled 18 CF patients (age, 7.7 ± 2.0 years) and 15 non-CF patients (age, 6.4 ± 2.5 years). The age difference was not significant. The forced expiratory volume in the first second (FEV(1)) for the CF patients was 91 ± 15 %. The systolic annular velocity by TDI was significantly lower in the CF group. The RV strain values in the CF group were significantly lower in four of the six segments (RV free-wall base, RV free-wall mid, RV septal apex, and RV septal mid). The global strain value, the systolic strain rate, and the early diastolic strain rate were significantly lower in the CF group. Decreased systolic and diastolic RV properties were present in young healthy CF patients. Further studies with longitudinal follow-up evaluation are needed to determine the significance of these findings for the pediatric CF population.

QRS duration and mechanical dyssynchrony correlations with right ventricular function after fontan procedure

BACKGROUND

In studies of adult patients, increased QRS duration and mechanical dyssynchrony have been associated with decreased ventricular function. The aim of this study was to test the hypothesis that similar findings would be present in a population of patients with hypoplastic left heart syndrome (HLHS) after the Fontan procedure.

METHODS

A retrospective cross-sectional study was conducted. All patients with HLHS after the Fontan procedure were eligible. QRS duration was measured using 12-lead electrocardiography. Echocardiographic measurements of mechanical dyssynchrony included Doppler tissue imaging (DTI) QRS to onset of s' wave difference between the left ventricle and the right ventricle, time to peak strain, time to peak systolic strain rate (SRs), the standard deviation of time to peak strain rate (modified Yu strain), and the standard deviation of time to peak SRs (modified Yu SRs). Right ventricular (RV) functional measurements included DTI s' wave, DTI RV myocardial performance index, global strain, global SRs, and RV fractional area change. Pearson's correlations were performed between the variables.

RESULTS

Thirty-one echocardiographic studies were performed on 26 patients. The median age was 5.3 years (range, 2.5-15.4 years). QRS duration was correlated significantly with global SRs (r = 0.42). Time to peak SRs was correlated significantly with DTI s' wave (r = -0.48) and global SRs (r = 0.37). Modified Yu SRs was correlated significantly with global strain (r = 0.35) and RV fractional area change (r = -0.35).

CONCLUSIONS

Both QRS duration and mechanical dyssynchrony were correlated with RV function, albeit weakly. The clinical significance of these findings is intriguing, but only larger studies will determine if these measurements are reliable in guiding treatment options for this complex patient population.

Myocardial deformation in the fetal single ventricle

BACKGROUND

In postnatal life, patients with single ventricle (SV) with morphologic right ventricles have a worse prognosis than those with morphologic left ventricles. The aim of this study was to test the hypotheses that (1) the SV in fetuses with SV has decreased longitudinal strain compared with fetuses with normal cardiac anatomy, and (2) fetuses with SV right ventricular (RV) morphology have decreased strain compared with those with SV left ventricular (LV) morphology.

METHODS

Fetal echocardiograms with SV RV and SV LV morphology were retrospectively compiled. Postprocessing analysis of the dominant ventricle was done using syngo Velocity Vector Imaging version 2.0. Peak global longitudinal strain (GLS) and global longitudinal strain rate (GL SR) were generated. Both the right and left ventricles were analyzed in fetuses with normal cardiac anatomy for comparison.

RESULTS

Fifty-four fetuses with SV (18 with LV morphology and 36 with RV morphology) were included in the study and compared with 54 controls matched for gestational age. Global longitudinal strain and GL SR were compared between fetuses with SV and normal fetuses and among SV subsets. When all four categories were compared (normal left ventricle, normal right ventricle, SV left ventricle, and SV right ventricle), there was no difference in GLS (P = .49) or in GL SR (P = .32) between any of the categories.

CONCLUSIONS

Comparable GLS and GL SR values between fetal SV of LV or RV morphology, as well as normal fetal left and right ventricles, reflect in utero preservation of systolic function of the SV heart.