Current status of 3-dimensional speckle tracking echocardiography: a review from our experiences

Changes in Left Ventricular Function Assessed by 3D Echocardiography During Severe Central Hypovolemia in Healthy Humans

PURPOSE

Central hypovolemia is considered to lead to a compensatory increase in cardiac contractility. From a physiological perspective, left ventricular (LV) twisting motion, which plays an important role in maintaining cardiac output, should be enhanced during central hypovolemia, but previous studies have shown inconsistent findings. Using 3D echocardiography, we tested the hypothesis that the LV twisting and untwisting motion would be enhanced during severe central hypovolemia.

METHODS

Thirteen healthy men (25 ± 5 years old) underwent the maximal lower body negative pressure (LBNP) protocol; graded increase in LBNP loads up to presyncope. We evaluated the basic hemodynamics and LV function with 3D and Doppler echocardiography at each stage of LBNP. Indices were compared among baseline, half maximal LBNP (LBNP1/2max), and one stage before the presyncope (LBNPpre-max) to consider individual differences in orthostatic tolerance.

RESULTS

In response to LBNP, ejection fraction (baseline: 62 ± 3, LBNP1/2max: 55 ± 5, LBNPpre-max: 43% ± 9%, mean ± SD, p < 0.01, ANOVA), global longitudinal strain (-20.5 ± 2.8, -17.6 ± 2.7, -13.6% ± 4.7%, p < 0.01), and global circumferential strain (-31.2 ± 3.7, -26.8 ± 3.3, -19.4% ± 5.3%, p < 0.01) were weakened. Twist (15.2 ± 5.1, 14.5 ± 5.4, 20.9° ± 7.7°, p = 0.012) and peak untwisting rate (-138 ± 42, -164 ± 50, -245°/cm ± 88°/cm, p < 0.01) were strengthened at the LBNPpre-max. e' (14.1 ± 2.0, 11.1 ± 1.5, 8.2° ± 2.2 cm/s, p < 0.01) decreased in response to LBNP, while E/e' (5.8 ± 0.8, 5.4 ± 1.0, 7.8 ± 2.3, p < 0.01) increased at LBNPpre-max.

CONCLUSION

The present findings indicate that LV twisting motion is enhanced during severe central hypovolemia. On the other hand, conventional echocardiographic indices appeared to deteriorate. Intriguingly, an index of LV filling (E/e') was paradoxically enhanced during severe central hypovolemia.

Cardiac involvement in systemic lupus erythematosus: Interest of 2D global longitudinal strain

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disease of undetermined etiology. Cardiac involvement is common in SLE and constitutes one of the main causes of mortality. More recently, new ultrasound imaging techniques, such as transthoracic ultrasound (TTE) with strain evaluation, have appeared and seem promising for the detection of cardiac involvement. The objective of our work was to study the frequency and characteristics of ultrasound abnormalities found in lupus patients and to study the benefit of ultrasound with global longitudinal strain (GLS) for early management.

METHODS

It was an observational study of patients followed for SLE at the internal medicine and cardiology department of the HMPIT for 6 months (May-November 2023). The definition of cardiac involvement was by ultrasound. All patients benefited from TTE coupled with 2D-strain. We divided the workforce into two groups: the first group (patients with heart disease) and the second group (patients without heart disease).

RESULTS

In a series of 40 lupus patients including 33 women and seven men, cardiac manifestations were reported in 60% of patients. In the first group, 29% had palpitations, 25% had chest pain, 67% had dyspnea, 37% had pericarditis, 8% had pulmonary arterial hypertension (PAH) and 12% had myocarditis. The comparative study showed that patients in the first group presented significantly more frequently with dyspnea (p = 0.02), chest pain (p = 0.03) and serositis (p = 0.01) compared to those in the second group. The mean left ventricular ejection fraction (LVEF) did not show a significant difference between the two groups. On the other hand, the average Global Longitudinal Strain (GLS) was significantly altered in the first group (p = 0.01). Furthermore, the frequency of pathological GLS was significantly higher in patients with lupus heart disease (p < 0.01).

CONCLUSION

Cardiac involvement during SLE is a frequent and most often asymptomatic complication. A systematic search for this impairment using a high-performance echocardiography examination, namely the 2D GLS, is essential for early treatment.

Biventricular Dysfunction and Ventricular Interdependence in Patients With Pulmonary Hypertension: A 3.0-T Cardiac MRI Feature Tracking Study

BACKGROUND

Pulmonary hypertension (PH) results in right ventricular (RV) dysfunction, subsequently leading to left ventricular (LV) impairment. The mechanism underlying ventricular interdependence is largely uninvestigated.

PURPOSE

To explore the biventricular dysfunction and the ventricular interdependence in PH patients.

STUDY TYPE

Retrospective.

POPULATION

One hundred and seven PH patients (mean pulmonary artery pressure >20 mmHg) and 72 age- and sex-matched controls with cardiac magnetic resonance imaging (MRI) studies.

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady-state free precession sequence.

ASSESSMENT

LV and RV ejection fractions (EF) and RV and LV radial, circumferential, and longitudinal strains were assessed using commercial software. Strains were compared between controls, PH patients with preserved RVEF (RVEF ≥40%, N = 48), and PH patients with reduced RVEF (RVEF <40%, N = 59).

STATISTICAL TESTS

Chi-squared tests or Fisher's exact test, t tests or Mann-Whitney U test, one-way ANOVA with Bonferroni's post hoc correction or Kruskal-Wallis test, Pearson or Spearman correlation, and multivariable linear regression analysis. A two-tailed P < 0.05 was deemed statistically significant.

RESULTS

RV strain decreased sequentially from controls, through PH with preserved RVEF, to PH with reduced RVEF. PH patients with reduced RVEF had significantly lower LV strain, especially septal strain, and LV peak diastolic strain rate compared with both controls and PH patients with preserved RVEF. Multivariable analyses showed that RVEF was independently correlated with LV strain; furthermore, independent of RVEF, RV strain was significantly correlated with LV strain (LVGRS: β = 0.416; LVGCS: β = -0.371; LVGLS: β = 0.283).

DATA CONCLUSION

Subclinical impairment of RV function was found in PH with preserved RVEF. LV strain was impaired when RV was dysfunctional, which was associated with worsening RV strain. Therefore, while focusing on improving RV function, LV dysfunction in PH patients should also be monitored and treated early in order to slow the progression of the disease.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 3.

Neonatal Enterovirus-Associated Myocarditis in Dizygotic Twins: Myocardial Longitudinal Strain Pattern Analysis

Enteroviruses (EVs) are the most common causes of viral myocarditis in neonates. Neonatal enterovirus myocarditis manifestations range from nonspecific febrile illness to congestive heart failure and cardiogenic shock with high risk of in-hospital mortality and long-term cardiac sequelae. Early recognition is essential to undertake appropriate therapy and predict outcomes. Echocardiography and echo-derived left ventricular strain measures seem promising for these purposes. We herein report two cases of neonatal enterovirus-associated myocarditis in dichorionic diamniotic twins, with different presentation, clinical course, and intensity of treatments.

Screening for Peripheral Vascular Stiffness in Lipedema Patients by Automatic Electrocardiogram-Based Oscillometric Detection

Body mass index (BMI) is seen as a predictor of cardiovascular disease (CVD) in lipedema patients. A valid predictor of CVD is increased aortic stiffness (IAS), and previous research described IAS in lipedema. However, it is not known if this applies to all patients. In this cross-sectional single-center cohort study, peripheral pulse wave velocity (PWV) as a non-invasive indicator of aortic stiffness was measured in 41 patients with lipedema, irrespective of stage and without pre-existing cardiovascular conditions or a history of smoking and a maximum body mass index (BMI) of 35 kg/m2. Automatically electrocardiogram-triggered oscillometric sensor technology by the Gesenius-Keller method was used. Regardless of the stage of lipedema disease, there was no significant difference in PWV compared to published standard values adjusted to age and blood pressure. BMI alone is not a predictor of cardiovascular risk in lipedema patients. Measuring other anthropometric factors, such as the waist-hip ratio or waist-height ratio, should be included, and the existing cardiovascular risk factors, comorbidities, and adipose tissue distribution for accurate risk stratification should be taken into account. Automated sensor technology recording the PWV represents a valid and reliable method for health monitoring and early detection of cardiovascular risks.

Use of speckle tracking echocardiography in evaluating cardiac dysfunction in patients with acromegaly: an update

In recent years, cardiovascular disease has garnered increasing attention as the second leading cause of death in individuals with acromegaly, following malignancy. Identifying cardiac dysfunction early in acromegaly patients for timely intervention has become a focal point of clinical research. Speckle tracking echocardiography, a well-established ultrasound technique, surpasses conventional Doppler ultrasound in its sensitivity to assess both local and global cardiac mechanics. It can accurately detect subclinical and clinical myocardial dysfunction, including myocardial ischemia, ventricular hypertrophy, and valvular changes. Over the past five years, the use of speckle tracking echocardiography in acromegaly patients has emerged as a novel approach. Throughout the cardiac cycle, speckle tracking echocardiography offers a sensitive evaluation of the global and regional myocardial condition by quantifying the motion of myocardial fibres in distinct segments. It achieves this independently of variations in ultrasound angle and distance, effectively simulating the deformation of individual ventricles across different spatial planes. This approach provides a more accurate description of changes in cardiac strain parameters. Importantly, even in the subclinical stage when ejection fraction remains normal, the strain parameters assessed by speckle tracking echocardiography hold a good predictive value for the risk of cardiovascular death and hospitalization in acromegaly patients with concomitant cardiovascular disease. This information aids in determining the optimal timing for interventional therapy, offering important insights for cardiac risk stratification and prognosis. In the present study, we comprehensively reviewed the research progress of speckle tracking echocardiography in evaluating of cardiac dysfunction in acromegaly patients, to pave the way for early diagnosis of acromegaly cardiomyopathy.

Prediction of Deterioration of Left Ventricular Function Using 3-Dimensional Speckle-Tracking Echocardiography in Patients With Left Bundle-Branch Block

Background Previous studies have demonstrated that 2-dimensional (2D) global longitudinal strain (GLS) is associated with cardiovascular outcomes in patients with left bundle-branch block. However, the predictive value of 3-dimensional (3D) speckle-tracking echocardiography has not yet been investigated in these patients. Methods and Results The authors retrospectively identified 290 patients with left bundle-branch block who underwent echocardiography more than twice. Using speckle-tracking echocardiography, 2D-GLS, 3D-GLS, 3D-global circumferential strain, 3D global radial strain, and 3D global area strain were acquired. The association between 2D and 3D strains and the follow-up left ventricular (LV) ejection fraction (LVEF) was analyzed. The study population was divided into 2 sets: a group with preserved LVEF (baseline LVEF ≥40%) and a group with reduced LVEF (baseline LVEF <40%). After a median follow-up of 29.1 months (interquartile range, 13.1-53.0 months), 14.9% of patients progressed to LV dysfunction in the group with preserved LVEF, and 51.0% of patients showed improved LV function in the group with reduced LVEF. Multivariable analysis of 2D and 3D strains revealed that higher 2D-GLS (odds ratio [OR], 0.65 [95% CI, 0.54-0.78], P<0.001) was highly associated with maintaining LVEF in patients with preserved LVEF. However, a lower 3D-global circumferential strain (OR, 0.61 [95% CI, 0.47-0.78], P<0.001) showed a strong association with persistently reduced LVEF in patients with reduced LVEF. Conclusions Although 2D-GLS showed a powerful predictive value for the deterioration of LV function in the preserved LVEF group, 3D strain, especially 3D-global circumferential strain, can be helpful to predict consistent LV dysfunction in patients with left bundle-branch block who have reduced LVEF.

Clinical Utility of Three-Dimensional Speckle-Tracking Echocardiography in Heart Failure

Heart failure (HF) is an extremely major health problem with gradually increasing incidence in developed and developing countries. HF may lead to cardiac remodeling; thus, advanced imaging techniques are required to comprehensively evaluate cardiac mechanics. Recently, three-dimensional speckle-tracking echocardiography (3D-STE) has been developed as a novel imaging technology that is based on the three-dimensional speckle-tracking on the full volume three-dimensional datasets. Three-dimensional speckle-tracking echocardiography allows a more accurate evaluation of global and regional myocardial performance, assessment of cardiac mechanics, detection of subclinical cardiac dysfunction, and prediction of adverse clinical events in a variety of cardiovascular diseases. Therefore, this review summarizes the clinical usefulness of 3D-STE in patients with HF.

Normal reference values of left ventricular strain parameters in healthy adults: Real-life experience from the single-center three-dimensional speckle-tracking echocardiographic MAGYAR-Healthy Study

INTRODUCTION

A number of studies defined normal reference values of three-dimensional (3D) speckle-tracking echocardiography (3DSTE)-derived left ventricular (LV) strains. The present study aimed to quantify normal reference values of LV strains in healthy adult population in real clinical world settings in different age groups, and to determine age- and gender-dependence of these variables in a high volume single center.

METHODS

The present prospective study included 296 healthy adult subjects. Among them, 124 were excluded due to inferior image quality during the 6-year recruitment period (2011-2017). The remaining population was further divided into four subgroups based on age decades.

RESULTS

While global radial (RS) strain showed an increase-decrease-increase pattern with age, circumferential, longitudinal, and area strains (CS, LS, AS, respectively) were nonsignificantly lower in older ages. Only global LV-LS showed gender-dependency with higher values in females. Although moderately higher RS and 3DS and lower LS, and AS were observed in males, clear gender-dependency could not be detected in different age decades.

CONCLUSIONS

This study provides normal reference values of 3DSTE-derived global, segmental, mean segmental, and regional LV strains in healthy adult subjects based on real-life clinical experience. Age-, gender-, and functional nonuniformity of LV strains were also defined.

Normal reference values of three-dimensional speckle-tracking echocardiography-derived right atrial volumes and volume-based functional properties in healthy adults (Insights from the MAGYAR-Healthy Study)

INTRODUCTION

The right atrium (RA) roles include being a systolic reservoir, an early diastolic conduit, and a late-diastolic booster pump. The present study aimed to assess normal reference values of three-dimensional speckle-tracking echocardiography (3DSTE)-derived RA volumetric data and volume-based functional properties in healthy adult subjects.

METHODS

We included 260 healthy adult subjects in sinus rhythm with complete clinical and demographic dataset, but excluded 110 of them because of inferior image quality. The remaining population sample comprised 150 subjects (31.0 ± 11.6 years, 79 males). Complete two-dimensional Doppler echocardiography and 3DSTE have been performed in all subjects.

RESULTS

Systolic RA volumetric variables did not show changes over time, but after 50 years, a significant reduction could be demonstrated in RA stroke volume and emptying fraction. While early diastolic RA volume increased over time, RA stroke volume and emptying fraction decreased. While late-diastolic RA volume increased over age decades, similar increase could be detected in RA stroke volume but a reduction occurred in older ages. Late-diastolic RA emptying fraction showed an increasing (after the 40s)-decreasing (after the 50s) pattern.

CONCLUSIONS

Our study provides normal reference values of 3DSTE-derived RA volumes and volume-based functional properties and their age- and gender dependency in healthy adult subjects.

The right atrium in acromegaly-a three-dimensional speckle-tracking echocardiographic analysis from the MAGYAR-Path Study

BACKGROUND

Acromegaly is a chronic, rare hormonal disease associated with major cardiovascular co-morbidities. The disease, in the majority of the cases, is caused by a benign human growth hormone (hGH) secreting adenoma. Cardiovascular involvement is especially common in acromegalic patients from the most common hypertension to cardiomyopathy. Left ventricular hypertrophy and myocardial fibrosis are considered common findings in acromegalic cardiomyopathy, which might result in severe heart failure at end-stages. It was set out to quantify right atrial (RA) morphology and function in a group of acromegalic patients using three-dimensional (3D) speckle-tracking echocardiography (3DSTE).

METHODS

The study comprised 30 patients from which 8 patients were excluded due to inadequate image quality. Mean age of the remaining acromegaly patients were 53.7±14.5 years (7 males). In the control group 44 healthy adults were enrolled (mean age: 50.7±12.6 years, 15 males). In each case, complete two-dimensional Doppler echocardiography was performed followed by 3DSTE.

RESULTS

All three RA volumetric parameters (Vmax, Vmin, VpreA) were significantly higher in case of acromegaly compared to the healthy controls. Strain analysis revealed that RA function may be enhanced in acromegalic patients, which is more notable in case of active acromegaly. Numerous independent strain parameters had significant correlations with different hormonal variables in the active acromegaly group. These correlations were not present in the inactive acromegaly subgroup.

CONCLUSIONS

Acromegaly has a profound effect on RA function and with proper treatment these changes partly seem to be reversible.

Current Understanding of the Biomechanics of Ventricular Tissues in Heart Failure

Heart failure is the leading cause of death worldwide, and the most common cause of heart failure is ventricular dysfunction. It is well known that the ventricles are anisotropic and viscoelastic tissues and their mechanical properties change in diseased states. The tissue mechanical behavior is an important determinant of the function of ventricles. The aim of this paper is to review the current understanding of the biomechanics of ventricular tissues as well as the clinical significance. We present the common methods of the mechanical measurement of ventricles, the known ventricular mechanical properties including the viscoelasticity of the tissue, the existing computational models, and the clinical relevance of the ventricular mechanical properties. Lastly, we suggest some future research directions to elucidate the roles of the ventricular biomechanics in the ventricular dysfunction to inspire new therapies for heart failure patients.

3D angle-independent Doppler and speckle tracking for the myocardium and blood flow

A technology based on velocity ratio indices is described for application in the myocardium. Angle-independent Doppler indices, such as the pulsatility index, which employ velocity ratios, can be measured even if the ultrasound beam vector at the moving target and the motion vector are not in a known plane. The unknown plane situation is often encountered when an ultrasound beam interrogates sites in the myocardium. The velocities employed in an index calculation must be close to the same or opposite directions. The Doppler velocity ratio indices are independent of angle in 3D space as are ratio indices based on 1D strain and 1D speckle tracking. Angle-independent results with spectral Doppler methods are discussed. Possible future imaging techniques based on velocity ratios are presented. By using indices that involve ratios, several other sources of error cancel in addition to that of angular dependence for example errors due to less than optimum gain settings and beam distortion. This makes the indices reliable as research or clinical tools. Ratio techniques can be readily implemented with current commercial blood flow pulsed wave duplex Doppler equipment or with pulsed wave tissue Doppler equipment. In 70 patients where the quality of the real-time B-mode looked suitable for the Doppler velocity ratio technique, there was only one case where clear spectra could not be obtained for both the LV wall and the septum. A reproducibility study of spectra from the septum of the heart shows a 12% difference in velocity ratios in the repeat measurements.

Relation of blood pressure variability to left ventricular function and arterial stiffness in hypertensive patients

INTRODUCTION

Variability of blood pressure (BP) has been reported to be related to worse cardiovascular outcomes. We examined the impact of daytime systolic BP variability on left ventricular (LV) function and arterial stiffness in hypertensive patients.

METHODS

Ambulatory BP monitoring (ABPM) and echocardiography were performed in 116 hypertensive patients. We assessed BP variability as standard deviations of daytime systolic BP on 24-hour ABPM. Conventional echocardiographic parameters, area strain and three-dimensional diastolic index (3D-DI) using 3D speckle tracking were measured. Arterial stiffness was evaluated by acquiring pulse wave velocity (PWV) and augmentation index.

RESULTS

Patients with higher BP variability showed significantly increased left ventricular mass index (LVMI) and late mitral inflow velocity, as well as decreased E/A (early mitral inflow velocity/late mitral inflow velocity) ratio, area strain and 3D-DI than those with lower BP variability (LVMI: p = 0.02; A velocity: p < 0.001; E/A ratio: p < 0.001; area strain: p = 0.02; 3D-DI: p = 0.04). In addition, increased BP variability was associated with higher PWV and augmentation index (p < 0.001). Even among patients whose BP was well controlled, BP variability was related to LV mass, diastolic dysfunction and arterial stiffness.

CONCLUSION

Increased BP variability was associated with LV mass and dysfunction, as well as arterial stiffness, suggesting that BP variability may be an important determinant of target organ damage in hypertensive patients.

Identification of significant coronary artery disease in patients with non-ST segment elevation acute coronary syndrome by myocardial strain analyses using three dimensional speckle tracking echocardiography

BACKGROUND

Speckle-tracking imaging is a novel method for assessing left ventricular function and ischemic changes. This study aimed to predict the presence of significant coronary artery stenosis in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) by 3D strain analysis using speckle tracking echocardiography (3DSTE) at rest.

METHODS

This cross-sectional study included a total 60 patients with NSTE-ACS who underwent 3DSTE immediately prior to coronary angiography. Subsequently, patients undergone coronary angiogram (CAG) and divided into two groups; group- I: significant stenosis (n = 36), group-II: non-significant stenosis (n = 24).

RESULTS

Global peak systolic longitudinal strain (GPSLS), circumferential strain (CS), area strain (AS), and radial strain (RS) were obtained successfully in 60 patients. All strain parameters were significantly reduced in patient group of significant stenosis. Receiver operating characteristic (ROC) curve analysis demonstrated that GPSLS could effectively detect patients with significant stenosis (area under ROC curve = 0.840, 95% CI = 0.735-0.945). GPSLS with a cutoff value of -13.50% showed good sensitivity and specificity for predicting significant stenosis (sensitivity 88.9% and specificity 70.8%).

CONCLUSION

Global peak systolic longitudinal strain using 3D speckle tracking echocardiography at rest was significantly lower in patients with significant stenosis and might be useful for identifying patients with a significant stenosis with good degree of sensitivity and specificity.

Left ventricular twist is impaired in acromegaly: Insights from the three-dimensional speckle tracking echocardiographic MAGYAR-Path Study

INTRODUCTION

Acromegaly is a rare, chronic, disfiguring, and debilitating disease caused, in 90% of cases, by a benign monoclonal growth hormone-secreting pituitary adenoma. The present study aimed to assess left ventricular (LV) rotational and twist mechanics in acromegalic patients and to compare their results to age- and gender-matched healthy controls.

METHODS

The present study comprised 24 acromegalic patients, from which 4 were excluded due to insufficient image quality (mean age: 57.8 ± 13.7 years, 7 men). The control group consisted of 18 age- and gender-matched healthy individuals (mean age: 54.8 ± 6.9 years, 8 men).

RESULTS

In 4 out of 20 acromegalic patients, LV showed near absence of twist, as the so-called LV "rigid body rotation" (RBR). Between all acromegalic patients without LV-RBR and controls, both LV basal (-3.76 ± 1.73 vs. -6.17 ± 2.66°, P = .004) and apical rotation (6.12 ± 4.03 vs. 10.81 ± 3.65°, P = .001) and LV twist (9.88 ± 4.74 vs. 16.98 ± 3.88°, P < .001) differed significantly. Between active and nonactive acromegaly subgroups, only the time-to-peak LV twist (377 ± 78 vs. 229 ± 97 ms, P = .005) showed significant difference.

CONCLUSIONS

Acromegaly is associated with impaired LV rotation and twist as assessed by 3-dimensional speckle tracking echocardiography. LV-RBR is a frequent phenomenon in acromegaly.

Breakthroughs in modern cancer therapy and elusive cardiotoxicity: Critical research-practice gaps, challenges, and insights

To date, five cancer treatment modalities have been defined. The three traditional modalities of cancer treatment are surgery, radiotherapy, and conventional chemotherapy, and the two modern modalities include molecularly targeted therapy (the fourth modality) and immunotherapy (the fifth modality). The cardiotoxicity associated with conventional chemotherapy and radiotherapy is well known. Similar adverse cardiac events are resurging with the fourth modality. Aside from the conventional and newer targeted agents, even the most newly developed, immune-based therapeutic modalities of anticancer treatment (the fifth modality), e.g., immune checkpoint inhibitors and chimeric antigen receptor (CAR) T-cell therapy, have unfortunately led to potentially lethal cardiotoxicity in patients. Cardiac complications represent unresolved and potentially life-threatening conditions in cancer survivors, while effective clinical management remains quite challenging. As a consequence, morbidity and mortality related to cardiac complications now threaten to offset some favorable benefits of modern cancer treatments in cancer-related survival, regardless of the oncologic prognosis. This review focuses on identifying critical research-practice gaps, addressing real-world challenges and pinpointing real-time insights in general terms under the context of clinical cardiotoxicity induced by the fourth and fifth modalities of cancer treatment. The information ranges from basic science to clinical management in the field of cardio-oncology and crosses the interface between oncology and onco-pharmacology. The complexity of the ongoing clinical problem is addressed at different levels. A better understanding of these research-practice gaps may advance research initiatives on the development of mechanism-based diagnoses and treatments for the effective clinical management of cardiotoxicity.

Biomechanical Properties and Mechanobiology of Cardiac ECM

The heart is comprised of cardiac cells and extracellular matrix (ECM) which function together to pump blood throughout the body, provide organs with nutrients and oxygen, and remove metabolic wastes. Cardiac ECM provides a scaffold to cardiac cells and contributes to the mechanical properties and function of the cardiac tissue. Recently, more evidence suggests that cardiac ECM plays an active role in cardiac remodeling in response to mechanical loads. To that end, we provide an overview of the structure and function of the heart and the currently available in vivo and ex vivo mechanical measurements of cardiac tissues. We also review the biomechanical properties of cardiac tissues including the myocardium and heart valves, with a discussion on the differences between the right ventricle and left ventricle. Lastly, we go into the mechanical factors involved in cardiac remodeling and review the mechanobiology of cardiac tissues, i.e., the biomechanical responses at the cellular and tissue level, with an emphasis on the impact on the cardiac ECM. The regulation of cardiac ECM on cell function, which is a new and open area of research, is also briefly discussed. Future investigation into the ECM deposition and the interaction of cardiac cells and ECM components for mechanotransduction can assist to understand cardiac remodeling and inspire new therapies for cardiac diseases.

Left atrial deformation: Useful index for early detection of cardiac damage in chronic mitral regurgitation

In chronic mitral regurgitation (MR) left atrium is one of the first cardiac structures that is involved in remodeling and ultrastructural changes for a progressive volume overload. Severe left atrial (LA) dilation on echocardiography and new onset of atrial fibrillation in asymptomatic patients with preserved Left Ventricular (LV) function, appeared as a Class IIb recommendation for consideration for surgical mitral valve repair in the actual guidelines. However, before atrial dilatation and dysfunction, several ultrastructural changes appear in the atrial muscle tissue that are difficult to identify with the standard echocardiography. Speckle tracking echocardiography (STE) can analyze LA function: it has been showed that it can indirectly identify structural tissue modifications from excessive atrial effort in the early stages of MR up to the full depression of atrial function in the late stages where there are advanced ultrastructural alterations. This review aims to summarize current knowledge on the role of atrial strain identifying early structural alterations of the atrial tissue in the rising stages of MR considering that Left Atrial Peak Longitudinal Strain (PALS) considered useful parameter for a more extensive evaluation of MR patients.

Quantification of mechanical dyssynchrony in growth restricted fetuses and normal controls using speckle tracking echocardiography (STE)

PURPOSE

To evaluate longitudinal mechanical dyssynchrony in normally grown fetuses by speckle tracking echocardiography (STE) and to compare longitudinal mechanical dyssynchrony in fetal growth restriction (FGR) with normal controls.

MATERIALS AND METHODS

A prospective study was performed on 30 FGR and 62 normally grown fetuses, including 30 controls matched by gestational age, using STE and a transversal four-chamber view. Data analysis was carried out with a high frame rate of about 175 frames/s. Dyssynchrony was analyzed offline with QLab 9 (Philips Medical Systems, Andover, MA, USA) as time differences between peaks in strain of both ventricles and the septum. Inter- and intraventricular and intraseptal dyssynchrony were obtained and inter- and intraobserver reliability was analyzed.

RESULTS

Longitudinal mechanical dyssynchrony was feasible in all cases, with high inter- and intraobserver reliability. Levels of inter- and intraventricular dyssynchrony were higher in the FGR than in the control group.

CONCLUSION

Speckle tracking echocardiography (STE) is a reliable technique for cardiac function assessment in the fetal heart. Interventricular dyssynchrony could be a potential parameter for early detection of subclinical myocardial dysfunction before other parameters demand intervention. The future clinical role of longitudinal mechanical dyssynchrony needs to be verified in larger studies and with a technique customized for prenatal echocardiography.

Global longitudinal strain corrected by RR interval is a superior predictor of all-cause mortality in patients with systolic heart failure and atrial fibrillation

AIMS

Quantification of systolic function in patients with atrial fibrillation (AF) is challenging. A novel approach, based on RR interval correction, to counteract the varying heart cycle lengths in AF has recently been proposed. Whether this method is superior in patients with systolic heart failure (HFrEF) with AF remains unknown. This study investigates the prognostic value of RR interval-corrected peak global longitudinal strain {GLSc = GLS/[RR^(1/2)]} in relation to all-cause mortality in HFrEF patients displaying AF during echocardiographic examination.

METHODS AND RESULTS

Echocardiograms from 151 patients with HFrEF and AF during examination were analysed offline. Peak global longitudinal strain (GLS) was averaged from 18 myocardial segments obtained from three apical views. GLS was indexed with the square root of the RR interval {GLSc = GLS/[RR^(1/2)]}. Endpoint was all-cause mortality. During a median follow-up of 2.7 years, 40 patients (26.5%) died. Neither uncorrected GLS (P = 0.056) nor left ventricular ejection fraction (P = 0.053) was significantly associated with all-cause mortality. After RR^(1/2) indexation, GLSc became a significant predictor of all-cause mortality (hazard ratio 1.16, 95% confidence interval 1.02-1.22, P = 0.014, per %/s^(1/2) decrease). GLSc remained an independent predictor of mortality after multivariable adjustment (age, sex, mean heart rate, mean arterial blood pressure, left atrial volume index, and E/e') (hazard ratio 1.17, 95% confidence interval 1.05-1.31, P = 0.005 per %/s^(1/2) decrease).

CONCLUSIONS

Decreasing {GLSc = GLS/[RR^(1/2)]}, but not uncorrected GLS nor left ventricular ejection fraction, was significantly associated with increased risk of all-cause mortality in HFrEF patients with AF and remained an independent predictor after multivariable adjustment.

Current Clinical Applications of Three-Dimensional Echocardiography: When the Technique Makes the Difference

Advances in ultrasound, computer, and electronics technology have permitted three-dimensional echocardiography (3DE) to become a clinically viable imaging modality, with significant impact on patient diagnosis, management, and outcome. Thanks to the inception of a fully sampled matrix transducer for transthoracic and transesophageal probes, 3DE now offers much faster and easier data acquisition, immediate display of anatomy, and the possibility of online quantitative analysis of cardiac chambers and heart valves. The clinical use of transthoracic 3DE has been primarily focused, albeit not exclusively, on the assessment of cardiac chamber volumes and function. Transesophageal 3DE has been applied mostly for assessing heart valve anatomy and function. The advantages of using 3DE to measure cardiac chamber volumes derive from the lack of geometric assumptions about their shape and the avoidance of the apical view foreshortening, which are the main shortcomings of volume calculations from two-dimensional echocardiographic views. Moreover, 3DE offers a unique realistic en face display of heart valves, congenital defects, and surrounding structures allowing a better appreciation of the dynamic functional anatomy of cardiac abnormalities in vivo. Offline quantitation of 3DE data sets has made significant contributions to our mechanistic understanding of normal and diseased heart valves, as well as of their alterations induced by surgical or interventional procedures. As reparative cardiac surgery and transcatheter procedures become more and more popular for treating structural heart disease, transesophageal 3DE has expanded its role as the premier technique for procedure planning, intra-procedural guidance, as well as for checking device function and potential complications after the procedure.

Comparison of two-dimensional and three-dimensional echocardiographic strain in children with CHD

BACKGROUND

In CHD, three-dimensional strain analysis may overcome limitations of Doppler and two-dimensional strain of the left ventricle. The aims of this study were to evaluate feasibility and reproducibility of three-dimensional longitudinal, circumferential, and radial systolic strain by three-dimensional speckle-tracking echocardiography compared with two-dimensional echocardiography.

METHODS

Patients with CHD, biventricular circulation with a systemic left ventricle, and who had two- and three-dimensional imaging performed on the same day from 2010 to 2014 were included. Quantitative two- and three-dimensional strain analyses were performed (two-dimensional cardiac performance analysis version 1.2 and four-dimensional left ventricular analysis version 3.1). Intra- and inter-observer variabilities were calculated on 25 studies.

RESULTS

A total of 30 patients, including 19 (61%) males, with a median age of 3.6 years (0.1-22 years) were included. The mean fractional shortening was 34.6±5.3%, and the mean ejection fraction was 62.0±6.4%. Measurement of two- and three-dimensional strain was feasible in >95% of segments. Good correlation was observed between longitudinal and circumferential strain (r=0.92, p⩽0.001 and r=0.87, p⩽0.001), but not radial strain (r=0.29, p=0.2). Intra- and inter-observer agreements were better for three-dimensional compared with two-dimensional strain, and better for both two- and three-dimensional longitudinal and circumferential strains compared with radial strain.

CONCLUSION

Left ventricular three-dimensional strain analysis is feasible in children with CHD. The reproducibility of longitudinal and circumferential strain by three-dimensional analyses is better. Further longitudinal studies are warranted for the potential clinical application of this new technology.

The impact of preload on 3-dimensional deformation parameters: principal strain, twist and torsion

Background

Strain analysis is feasible using three-dimensional (3D) echocardiography. This approach provides various parameters based on speckle tracking analysis from one full-volume image of the left ventricle; however, evidence for its volume independence is still lacking.

Methods

Fifty-eight subjects who were examined by transthoracic echocardiography immediately before and after hemodialysis (HD) were enrolled. Real-time full-volume 3D echocardiographic images were acquired and analyzed using dedicated software. Two-dimensional (2D) longitudinal strain (LS) was also measured for comparison with 3D strain values.

Results

Longitudinal (pre-HD: −24.57 ± 2.51, post-HD: −21.42 ± 2.15, P < 0.001); circumferential (pre-HD: −33.35 ± 3.50, post-HD: −30.90 ± 3.22, P < 0.001); and radial strain (pre-HD: 46.47 ± 4.27, post-HD: 42.90 ± 3.61, P < 0.001) values were significantly decreased after HD. The values of 3D principal strain (PS), a unique parameter of 3D images, were affected by acute preload changes (pre-HD: −38.10 ± 3.71, post-HD: −35.33 ± 3.22, P < 0.001). Twist and torsion values were decreased after HD (pre-HD: 17.69 ± 7.80, post-HD: 13.34 ± 6.92, P < 0.001; and pre-HD: 2.04 ± 0.86, post-HD:1.59 ± 0.80, respectively, P < 0.001). The 2D LS values correlated with the 3D LS and PS values.

Conclusion

Various parameters representing left ventricular mechanics were easily acquired from 3D echocardiographic images; however, like conventional parameters, they were affected by acute preload changes. Therefore, strain values from 3D echocardiography should be interpreted with caution while considering the preload conditions of the patients.

Echocardiographic Techniques of Deformation Imaging in the Evaluation of Maternal Cardiovascular System in Patients with Complicated Pregnancies

Cardiovascular diseases (CVD) represent the leading cause of maternal mortality and morbidity. Knowledge of CVD in women is constantly evolving and data are emerging that female-specific risk factors as complications of pregnancy are conditions associated with an increased risk for the long-term development of CVD. Echocardiography is a safe and effective imaging technique indicated in symptomatic or asymptomatic pregnant women with congenital heart diseases who require close monitoring of cardiac function. Deformation imaging is an echocardiographic technique used to assess myocardial function by measuring the actual deformation of the myocardium through the cardiac cycle. Speckle-tracking echocardiography (STE) is a two-dimensional (2D) technique which has been found to be more accurate than tissue Doppler to assess both left ventricular (LV) and right ventricular (RV) myocardial function. The use of 2D STE however might present some technical issues due to the tomographic nature of the technique and the motion in the three-dimensional space of the myocardial speckles. This has promoted the use of 3D STE to track the motion of the speckles in the 3D space. This review will focus on the clinical value of the new echocardiographic techniques of deformation imaging used to assess the maternal cardiovascular system in complicated pregnancies.

Magnetic Resonance Imaging of Myocardial Strain After Acute ST-Segment-Elevation Myocardial Infarction: A Systematic Review

The purpose of this systematic review is to provide a clinically relevant, disease-based perspective on myocardial strain imaging in patients with acute myocardial infarction or stable ischemic heart disease. Cardiac magnetic resonance imaging uniquely integrates myocardial function with pathology. Therefore, this review focuses on strain imaging with cardiac magnetic resonance. We have specifically considered the relationships between left ventricular (LV) strain, infarct pathologies, and their associations with prognosis. A comprehensive literature review was conducted in accordance with the PRISMA guidelines. Publications were identified that (1) described the relationship between strain and infarct pathologies, (2) assessed the relationship between strain and subsequent LV outcomes, and (3) assessed the relationship between strain and health outcomes. In patients with acute myocardial infarction, circumferential strain predicts the recovery of LV systolic function in the longer term. The prognostic value of longitudinal strain is less certain. Strain differentiates between infarcted versus noninfarcted myocardium, even in patients with stable ischemic heart disease with preserved LV ejection fraction. Strain recovery is impaired in infarcted segments with intramyocardial hemorrhage or microvascular obstruction. There are practical limitations to measuring strain with cardiac magnetic resonance in the acute setting, and knowledge gaps, including the lack of data showing incremental value in clinical practice. Critically, studies of cardiac magnetic resonance strain imaging in patients with ischemic heart disease have been limited by sample size and design. Strain imaging has potential as a tool to assess for early or subclinical changes in LV function, and strain is now being included as a surrogate measure of outcome in therapeutic trials.

Clinical feasibility and validation of 3D principal strain analysis from cine MRI: comparison to 2D strain by MRI and 3D speckle tracking echocardiography

Two-dimensional (2D) strain analysis is constrained by geometry-dependent reference directions of deformation (i.e. radial, circumferential, and longitudinal) following the assumption of cylindrical chamber architecture. Three-dimensional (3D) principal strain analysis may overcome such limitations by referencing intrinsic (i.e. principal) directions of deformation. This study aimed to demonstrate clinical feasibility of 3D principal strain analysis from routine 2D cine MRI with validation to strain from 2D tagged cine analysis and 3D speckle tracking echocardiography. Thirty-one patients undergoing cardiac MRI were studied. 3D strain was measured from routine, multi-planar 2D cine SSFP images using custom software designed to apply 4D deformation fields to 3D cardiac models to derive principal strain. Comparisons of strain estimates versus those by 2D tagged cine, 2D non-tagged cine (feature tracking), and 3D speckle tracking echocardiography (STE) were performed. Mean age was 51 ± 14 (36% female). Mean LV ejection fraction was 66 ± 10% (range 37–80%). 3D principal strain analysis was feasible in all subjects and showed high inter- and intra-observer reproducibility (ICC range 0.83–0.97 and 0.83–0.98, respectively—p < 0.001 for all directions). Strong correlations of minimum and maximum principal strain were respectively observed versus the following: 3D STE estimates of longitudinal (r = 0.81 and r = −0.64), circumferential (r = 0.76 and r = −0.58) and radial (r = −0.80 and r = 0.63) strain (p < 0.001 for all); 2D tagged cine estimates of longitudinal (r = 0.81 and r = −0.81), circumferential (r = 0.87 and r = −0.85), and radial (r = −0.76 and r = 0.81) strain (p < 0.0001 for all); and 2D cine (feature tracking) estimates of longitudinal (r = 0.85 and −0.83), circumferential (r = 0.88 and r = −0.87), and radial strain (r = −0.79 and r = 0.84, p < 0.0001 for all). 3D principal strain analysis is feasible using routine, multi-planar 2D cine MRI and shows high reproducibility with strong correlations to 2D conventional strain analysis and 3D STE-based analysis. Given its independence from geometry-related directions of deformation this technique may offer unique benefit for the detection and prognostication of myocardial disease, and warrants expanded investigation.

Assessing the Performance of Ultrafast Vector Flow Imaging in the Neonatal Heart via Multiphysics Modeling and In Vitro Experiments

Ultrafast vector flow imaging would benefit newborn patients with congenital heart disorders, but still requires thorough validation before translation to clinical practice. This paper investigates 2-D speckle tracking (ST) of intraventricular blood flow in neonates when transmitting diverging waves at ultrafast frame rate. Computational and in vitro studies enabled us to quantify the performance and identify artifacts related to the flow and the imaging sequence. First, synthetic ultrasound images of a neonate's left ventricular flow pattern were obtained with the ultrasound simulator Field II by propagating point scatterers according to 3-D intraventricular flow fields obtained with computational fluid dynamics (CFD). Noncompounded diverging waves (opening angle of 60°) were transmitted at a pulse repetition frequency of 9 kHz. ST of the B-mode data provided 2-D flow estimates at 180 Hz, which were compared with the CFD flow field. We demonstrated that the diastolic inflow jet showed a strong bias in the lateral velocity estimates at the edges of the jet, as confirmed by additional in vitro tests on a jet flow phantom. Furthermore, ST performance was highly dependent on the cardiac phase with low flows (<5 cm/s), high spatial flow gradients, and out-of-plane flow as deteriorating factors. Despite the observed artifacts, a good overall performance of 2-D ST was obtained with a median magnitude underestimation and angular deviation of, respectively, 28% and 13.5° during systole and 16% and 10.5° during diastole.

Echocardiographic Predictors for Left Ventricular Remodeling after Acute ST Elevation Myocardial Infarction with Low Risk Group: Speckle Tracking Analysis

BACKGROUND

We sought to assess echocardiographic predictors of left ventricular (LV) adverse remodeling after successfully reperfused acute ST elevation myocardial infarction (STEMI). LV remodeling is commonly found in STEMI patients and it may suggest adverse outcome in acute myocardial infarction. We sought to identify whether 2D strain and torsion be independent parameters for prediction of LV adverse remodeling.

METHODS

We investigated 208 patients with low-risk STEMI patients who had follow up echocardiography at 6 or more months. After clinical assessments, all patients received revascularization according to current guideline. LV remodeling was defined as > 20% increase in end-diastolic volume (EDV) at follow up.

RESULTS

During the follow-up (11.9 ± 5.3 months), 53 patients (25.5%) showed LV remodeling. In univariate analysis, EDV, end-systolic volume, deceleration time (DT), CK-MB, and global longitudinal strain (GLS) were associated with LV remodeling. In multivariate analysis, EDV [hazard ratio (HR): 0.922, 95% confidence interval (CI): 0.897-0.948, p< 0.001],

GLS (HR

0.842, 95% CI: 0.728-0.974, p = 0.020), DT (HR: 0.989, 95% CI: 0.980-0.998, p = 0.023) and CK-MB (HR: 1.003, 95% CI: 1.000-1.005, p = 0.033) independently predicted LV remodeling. However, global circumferential strain, net twist, and twist or untwist rate were not associated with remodeling.

CONCLUSION

Of various parameters of speckle strain, only GLS predicted adverse remodeling in STEMI patients.

Longitudinal strain bull's eye plot patterns in patients with cardiomyopathy and concentric left ventricular hypertrophy

Despite substantial advances in the imaging techniques and pathophysiological understanding over the last decades, identification of the underlying causes of left ventricular hypertrophy by means of echocardiographic examination remains a challenge in current clinical practice. The longitudinal strain bull’s eye plot derived from 2D speckle tracking imaging offers an intuitive visual overview of the global and regional left ventricular myocardial function in a single diagram. The bull’s eye mapping is clinically feasible and the plot patterns could provide clues to the etiology of cardiomyopathies. The present review summarizes the longitudinal strain, bull’s eye plot features in patients with various cardiomyopathies and concentric left ventricular hypertrophy and the bull’s eye plot features might serve as one of the cardiac workup steps on evaluating patients with left ventricular hypertrophy.

Feasibility of Automated Three-Dimensional Rotational Mechanics by Real-Time Volume Transthoracic Echocardiography: Preliminary Accuracy and Reproducibility Data Compared with Cardiovascular Magnetic Resonance

BACKGROUND

Three-dimensional (3D) speckle-tracking echocardiography (STE) for myocardial strain imaging may be superior to two-dimensional STE, especially with respect to rotational mechanics. Automated strain measurements from nonstitched 3D STE may improve work flow and clinical utility. The aim of this study was to test the feasibility of model-based 3D STE for the automated measurement of voxel circumferential strain (Ecc) and myocardial rotation.

METHODS

Thirty-five individuals (12 healthy volunteers, 12 patients with dilated cardiomyopathy, and 11 patients with hypertensive left ventricular [LV] hypertrophy) were prospectively studied. The latter two groups did not have significant coronary artery disease on coronary arteriography. Tagged cardiovascular magnetic resonance (CMR) and feature-tracking CMR were used as reference standards. Regional (apex and mid left ventricle) and slice (within a region) Ecc and rotation were measured by real-time volume transthoracic echocardiography (nonstitched) using an automated algorithm.

RESULTS

Compared with both CMR techniques, apical and mid-LV Ecc (concordance correlation coefficients [CCCs], 0.84-0.95 and 0.48-0.68) and rotation (CCCs, 0.70-0.95 and 0.42-0.68) showed excellent, good, and moderate agreement, respectively. At the LV base, rotation showed poor agreement with CMR methods (CCC, 0.04-0.21), consistent with previous descriptions, but calculated LV twist showed moderate to good correlation with CMR techniques (CCC, 0.61-0.84). However, the 95% CI for measurements between techniques was wide, emphasizing the challenges in comparing voxel deformation by 3D echocardiography with CMR, compounded by differences in approaches to measuring deformation, and matching regional and slice measurements between techniques. Reproducibility (n = 10, including test-retest variability) of automated 3D strain and rotation measurements was good to excellent (coefficient of variation < 10%) and was comparable with that of CMR methods (coefficient of variation < 10%) in the same patients.

CONCLUSIONS

The data from this study show that automated measurements of voxel rotational mechanics by real-time volume transthoracic echocardiography is feasible and comparable with tagged CMR and feature-tracking CMR strain measurements, albeit with wide limits of agreement, emphasizing the differences between the modalities. Furthermore, this automated 3D speckle-tracking echocardiographic approach shows excellent reproducibility, including test-retest variability, comparable with that of the CMR methods.