Normal reference values of three-dimensional speckle-tracking echocardiography-derived left atrial strain parameters (results from the MAGYAR-Healthy Study)

High-Resolution Maps of Left Atrial Displacements and Strains Estimated With 3D Cine MRI Using Online Learning Neural Networks

The functional analysis of the left atrium (LA) is important for evaluating cardiac health and understanding diseases like atrial fibrillation. Cine MRI is ideally placed for the detailed 3D characterization of LA motion and deformation but is lacking appropriate acquisition and analysis tools. Here, we propose tools for the Analysis of Left Atrial Displacements and DeformatIons using online learning neural Networks (Aladdin) and present a technical feasibility study on how Aladdin can characterize 3D LA function globally and regionally. Aladdin includes an online segmentation and image registration network, and a strain calculation pipeline tailored to the LA. We create maps of LA Displacement Vector Field (DVF) magnitude and LA principal strain values from images of 10 healthy volunteers and 8 patients with cardiovascular disease (CVD), of which 2 had large left ventricular ejection fraction (LVEF) impairment. We additionally create an atlas of these biomarkers using the data from the healthy volunteers. Results showed that Aladdin can accurately track the LA wall across the cardiac cycle and characterize its motion and deformation. Global LA function markers assessed with Aladdin agree well with estimates from 2D Cine MRI. A more marked active contraction phase was observed in the healthy cohort, while the CVD $\text {LVEF}_{\downarrow } $ group showed overall reduced LA function. Aladdin is uniquely able to identify LA regions with abnormal deformation metrics that may indicate focal pathology. We expect Aladdin to have important clinical applications as it can non-invasively characterize atrial pathophysiology. All source code and data are available at: https://github.com/cgalaz01/aladdin_cmr_la.

Complex Associations Between Systolic Left Atrial and Left Ventricular Deformations in Healthy Adults-Detailed Analysis from the Three-Dimensional Speckle-Tracking Echocardiographic MAGYAR-Healthy Study

Introduction. Volumetric changes in the left atrium (LA) and left ventricle (LV) are strongly associated in healthy circumstances, as recent three-dimensional speckle-tracking echocardiographic (3DSTE) studies confirmed. However, the complex relationship of LA and LV deformation in systole has never been assessed in healthy individuals. The present study purposed to perform comparative simultaneous analysis of systolic LA and LV strains in healthy adults by 3DSTE. Methods. The study consisted of 165 healthy adults (mean age: 33.2 ± 12.3 years; 90 males). Complete two-dimensional Doppler echocardiography with 3DSTE was performed in all cases. Results. The increase in global LA radial strain (RS) and longitudinal strain (LS) showed no associations with LV strains. The largest global LA circumferential strain (CS) was associated with the largest basal LV-RS. Lowest basal and global LV-CS could be demonstrated in the presence of mean global LA-CS as compared to the presence of lower than mean global LA-CS. Global LA-RS showed an increase, with global LV-RS being largest when global LV-RS was the largest. Basal and global LA-RS were largest in the case of lowest global LV-CS. Basal LA-LS was largest in the case of mean global LV-CS. With the increase in global LV-LS, basal and global LA-LS showed an increase but only up to a point; in the case of larger than mean global LV-LS, no further increase was detected in basal and global LA-LS. Conclusions. Complex associations between simultaneously assessed LA and LV deformations represented by 3DSTE-derived strains could be demonstrated in healthy adults.

Detailed Insights into the Relationship Between Three-Dimensional Speckle-Tracking Echocardiography-Derived Systolic Left Atrial Global Strains and Left Ventricular Volumes in Healthy Adults from the MAGYAR-Healthy Study

Background and Objectives: The complex relationship between three-dimensional (3D) speckle-tracking echocardiography (3DSTE)-derived left ventricular (LV) and left atrial (LA) volumes and functional properties has been demonstrated in recent studies. A better understanding of LV volumetric dependence on systolic peak LA (reservoir) strains in healthy circumstances could complete this knowledge. Therefore, 3DSTE was used for the simultaneous evaluation of these parameters in healthy adults, aiming to examine their complex relationship. Materials and Methods: The present study consisted of 165 healthy individuals with a mean age of 33.1 ± 12.3 years and 90 men. A complete two-dimensional echocardiography with Doppler with 3DSTE was performed in all the cases. Results: The peak LA global radial (GRS), longitudinal (GLS), and 3D (G3DS) strains were increased in the subjects with a mean LV end-diastolic volume (EDV) as compared to those cases with a lower-than-mean LV-EDV. In the cases with a higher-than-mean LV-EDV, no further increase in these peak global LA strains could be detected. The peak LA global circumferential and area strains showed a tendentious (non-significant) increase with an increasing LV-EDV. The peak LA global strains showed similar non-significant associations with the LV end-systolic volume (except the peak LA-G3DS, which proved to be significant). Conclusions: In healthy adults, the 3DSTE-derived peak LA-GRS and LA-G3DS are increased with a larger LV-EDV up to a point, beyond which a further increase cannot be seen, suggesting a working Frank-Starling mechanism in this context similar to that for LA volumes. Similar associations are present for the peak LA-GLS as well.

Long-Term Prognostic Power of Three-Dimensional Speckle-Tracking Echocardiography-Derived Peak Left Atrial Reservoir Global Longitudinal Strain in Healthy Adults-An Analysis from the MAGYAR-Healthy Study

Introduction: The contraction-relaxation pattern of the left atrial (LA) walls is opposite to that detected in the left ventricle, which includes thinning in radial, lengthening in longitudinal, and widening in circumferential directions in the systolic reservoir phase of LA function as measured by three-dimensional speckle-tracking echocardiography (3DSTE). Global longitudinal strain (GLS) is a quantitative feature of longitudinal wall contraction referring to the whole LA. The present study aims to clarify the expected prognostic impact of peak LA-GLS as assessed by 3DSTE in healthy participants during a long-term follow-up period. Methods: The study consisted of 142 healthy adults (with an average age of 32.1 ± 12.7 years; 72 of the participants were men), in whom complete two-dimensional Doppler echocardiography and 3DSTE were performed on a voluntary basis. Results: Thirteen adults suffered from a cardiovascular event, including two cardiac deaths during a mean follow-up of 8.35 ± 4.20 years. Peak LA-GLS ≥ 20.9%, as assessed by 3DSTE, was found to be a significant predictor for cardiovascular event-free survival by using ROC analysis (specificity 74%, sensitivity 62%, area under the curve 0.69, p = 0.025). Healthy individuals with peak LA-GLS < 20.9% had a lower LV-EF and a significantly higher ratio of cardiovascular events compared to cases with peak LA-GLS ≥ 20.9%. Subjects who experienced cardiovascular events had lower peak LA-GLS and the ratio of subjects with peak LA-GLS < 20.9% proved to be significantly increased compared to that of cases without cardiovascular events. Conclusions: 3DSTE-derived peak LA-GLS representing LA lengthening in the end-systolic reservoir phase of LA function predicts future cardiovascular events in healthy adults.

High volume-rate echocardiography for simultaneous imaging of electromechanical activation and cardiac strain of the whole heart in a single heartbeat in humans

BACKGROUND

Imaging both electrical and mechanical cardiac function can better characterize cardiac disease and improve patient care. Currently, there is no noninvasive technique that can simultaneously image both electrical and mechanical function of the whole heart at the point of care. Here, our aim is to demonstrate that high volume-rate echocardiography can simultaneously map cardiac electromechanical activation and end-systolic cardiac strain of the whole heart in a single heartbeat.

METHOD

A 32x32 ultrasound matrix array connected to four synchronized ultrasound scanners were used for transthoracic high volume-rate imaging (840 volumes/s) in sixteen young volunteers (28.1±4.2 y.o.). An electromechanical activation map of the whole heart and volumetric end-systolic atrial and ventricular strain images were obtained.

RESULTS

The whole heart activation sequence was found to be consistent across volunteers and in agreement with previously reported normal electrical activation sequences. The mean electromechanical activation time was 72.6±15.2 ms in the atria, 132.4±19.7 ms in the ventricles and 154.5±19.6 ms in the whole heart. Volumetric right and left atrial as well as right and left ventricular strains were also consistent across all volunteers, with a mean end-systolic global longitudinal strain of 26.8±6.5% in the atria and -16.6±3.4% in the ventricles.

CONCLUSIONS

This initial feasibility study demonstrates that noninvasive high-volume rate imaging of the heart in a single heartbeat is feasible and can provide electromechanical activation and systolic strains simultaneously in all four cardiac chambers. This technique can be further developed and used at the point of care to assist for screening, diagnosis, therapy guidance and follow-up of heart disease patients.

Subclinical Left Atrial Remodeling in Healthy Adults with Left Ventricular 'Rigid Body Rotation'-Detailed Analysis from the Three-Dimensional Speckle-Tracking Echocardiographic MAGYAR-Healthy Study

Background. While the basal region of the left ventricle (LV) rotates in a clockwise (cw) direction, the apical regions of the LV rotate in a counterclockwise (ccw) direction in healthy circumstances. Although LV rotational mechanics help optimize LV ejection, in some cases, LV twist is missing. This clinical situation, when the LV base and the apex rotate in the same cw or ccw direction, is called LV 'rigid body rotation' (LV-RBR). Three-dimensional speckle-tracking echocardiography (3DSTE) seems to be optimal for the simultaneous assessment of the LV and the left atrium (LA). Therefore, the present study aimed to determine the features of LA remodeling in healthy adults having 3DSTE-derived LV-RBR as compared to subjects with normally directed LV rotational mechanics. Methods. This study consisted of 165 healthy subjects (mean age: 33.1 ± 12.3 years, 75 males), from which 156 individuals showed normally directed LV rotational mechanics, while 9 cases had LV-RBR. Results. When LV-RBR subjects were compared to subjects with normally directed LV rotational mechanics, all LA volumes were increased with preserved LA stroke volumes and (non-significantly) reduced LA emptying fractions. When subgroups were compared with each other, it has been clarified that an enlargement of the LA with increased volumes was limited only to ccwLV-RBR cases. While reduced global peak LA longitudinal strain could be detected in LV-RBR subjects as compared to subjects with normally directed LV rotational mechanics, which was limited to cases with the ccw form of LV-RBR (15.1 ± 4.7% vs. 26.6 ± 9.0%, p < 0.05), the global peak LA radial strain was increased in subjects with cwLV-RBR (-23.4 ± 6.3% vs. -14.7 ± 8.0%, p < 0.05). Increased global LA radial strain at atrial contraction could be detected in LV-RBR subjects (-9.9 ± 7.1% vs. -5.2 ± 5.2%, p < 0.05), which was present in both ccw and cw LV-RBR cases. Conclusions. In healthy adults presenting LV-RBR, subclinical LA remodeling could be detected in both forms of LV-RBR, but more pronounced in those who present a counterclockwise-oriented form.

Insights into the Associations Between Systolic Left Ventricular Rotational Mechanics and Left Atrial Peak Reservoir Strains in Healthy Adults from the MAGYAR-Healthy Study

INTRODUCTION

In systole, when the left ventricle (LV) twists, the left atrium (LA) behaves like a reservoir, having a special wall contractility pattern opposite to that of the LV wall. Accordingly, the objective of the present study was to investigate the associations between LV rotational mechanics and LA peak (reservoir) strains as assessed simultaneously by three-dimensional speckle-tracking echocardiography (3DSTE) under healthy conditions.

METHODS

In the present study, 157 healthy adults (mean age: 33.2 ± 12.7 years, 73 men) were involved. Complete two-dimensional Doppler echocardiography with 3DSTE-derived data acquisition were performed in all cases. The 3DSTE-derived LV rotational and LA strain parameters were determined at a later date.

RESULTS

Global LA peak reservoir circumferential (22.7 ± 6.4% vs. 27.6 ± 6.8%, p < 0.05) and area (57.8 ± 20.0% vs. 66.0 ± 22.7%, p < 0.05) strains proved to be reduced in the case of the highest vs. lowest basal LV rotation; other LA peak reservoir strains were not associated with increasing basal LV rotation. Global LA peak radial strain was highest in the case of the lowest vs. highest apical LV rotation (-19.2 ± 9.4% vs. -13.0 ± 8.2%, p < 0.05). Global LA peak reservoir 3D strain was lowest in the case of the highest vs. lowest apical LV rotation (-9.9 ± 6.8% vs. -5.0 ± 4.2%, p < 0.05). Only apical LV rotation proved to be significantly reduced in the case of the highest vs. lowest global LA peak reservoir 3D strain (8.12 ± 3.23° vs. 10.50 ± 3.44°, p < 0.05). Other global LA peak reservoir strains were not associated with basal and apical LV rotations.

CONCLUSIONS

In LV systole, LV rotational mechanics is associated with LA deformation represented by LA peak (reservoir) strains even in healthy circumstances. While basal LV rotation is associated with LA widening, apical LV rotation is associated with LA thinning, suggesting the close cooperation of the LV and LA in systole even in healthy adults.

Incremental diagnostic and prognostic utility of left atrial deformation in heart failure using speckle tracking echocardiography

Left atrium (LA) is a very important component of cardiovascular performance. The assessment of LA function has gathered the interest with expanding research supporting the utility as a biomarker for outcomes in heart failure (HF). Echocardiography is the main imaging modality which helps in a qualitative and quantitative assessment of the LA size and function. Recent advances in probe technology and software analysis have provided a better understanding of LA anatomy, physiology, pathology, and function. A variety of parameters have been defined as markers of LA function but there is no single parameter that best defines LA function. Speckle tracking echocardiography-derived analysis of LA deformation provides a window on all phases of LA function (reservoir, conduit, and booster pump). There is accumulative published data that supported the diagnostic and prognostic values of LA deformation integration during echo assessment of LA in HF. This review article summarized the clinical utility of LA deformation that may help in prediction, diagnosis, categorization, risk stratification, and guiding the proper selection of therapy in HF patients in daily practice.

Normal values for left atrial strain, volume, and function derived from 3D echocardiography: the Copenhagen City Heart Study

AIMS

3D echocardiographic (3DE) assessment of the left atrium (LA) is a new modality of potential clinical value. Age- and sex-based normative values are needed to benchmark these parameters for clinical use.

METHODS AND RESULTS

Of 4466 participants in the 5th Copenhagen City Heart Study, a prospective longitudinal cohort study on the general population, 2082 participants underwent 3DE of the LA. Healthy participants were included to establish normative values for LA strain, volume, and function by 3DE. The effects of age and sex were also evaluated. After excluding participants with comorbidities, 979 healthy participants (median age 44 years, 39.6% males) remained. The median and limits of normality (2.5th and 97.5th percentiles) for functional and volumetric measures were as follows: LA reservoir strain (LASr) 30.8% (18.4-44.2%), LA conduit strain (LAScd) 19.1% (6.8-32.0%), LA contractile strain 11.7% (4.3-22.2%), total LA emptying fraction (LAEF) 61.4% (47.8-71.0%), passive LAEF 37.7% (17.4-53.9%), active LAEF 37.4% (22.2-52.5%), LA minimum volume index (LAVimin) 10.2 (5.9-18.5) mL/m2, and LA maximum volume index (LAVimax) 26.8 (16.5-40.1) mL/m2. All parameters changed significantly with increasing age (P value for all <0.001). Significant sex-specific differences were observed for all parameters except active LAEF and LAVimax. Sex significantly modified the association between age and LASr (P for interaction < 0.001), LAScd (P for interaction < 0.001), LAVimin (P for interaction = 0.037), and total LAEF (P for interaction = 0.034) such that these parameters deteriorated faster with age in females than males.

CONCLUSION

We present age- and sex-specific reference material including limits of normality for LA strain, volume, and function by 3DE.

Correlations between vegetative autonomic function and specific left atrial functions in healthy adults: Insights from the three-dimensional speckle-tracking echocardiographic MAGYAR-Healthy Study

INTRODUCTION

The functioning of the left atrium (LA) is partly controlled by the neural system. It was purposed to evaluate correlations between the result of Ewing's 5 standard cardiovascular reflex tests (SCRTs) characterizing autonomic function and LA volumetric and functional features as assessed by three-dimensional speckle-tracking echocardiography (3DSTE) in healthy individuals.

MATERIALS AND METHODS

The current study comprised 18 healthy volunteers being in sinus rhythm (mean age: 35 ± 12 years, 10 men). Measurement of blood pressure, ECG, 5 SCRTs, two-dimensional Doppler echocardiography and 3DSTE were performed. These parameters were in normal ranges in all cases.

RESULTS

From LA volumetric parameters, only systolic total atrial emptying fraction (r = 0.559, p = 0.037) and early diastolic passive atrial emptying fraction (r = 0.539, p = 0.047) correlated with systolic blood pressure response to standing representing sympathetic autonomic function. From LA strains, peak mean segmental LA radial strain (RS) (r = -0.532, p = 0.050), global and mean segmental LA circumferential strain (CS) (r = 0.662, p = 0.010 and r = 0.635, p = 0.015, respectively) representing systolic LA function correlated with Valsalva ratio representing parasympathetic autonomic function. Global LA-RS (r = -0.713, p = 0.040) and LA-CS (r = 0.657, p = 0.011) and mean segmental LA-CS (r = 0.723, p = 0.003) at atrial contraction representing end-diastolic atrial contraction showed correlations with Valsalva ratio, as well. Peak global and mean segmental LA-CS (r = 0.532, p = 0.050 and r = 0.530, p = 0.050) and the same strains at atrial contraction (r = 0.704, p = 0.005 and r = 0.690, p = 0.006) representing systolic function and end-diastolic atrial contraction correlated with systolic blood pressure response to standing representing both parasympathetic and sympathetic autonomic functions.

CONCLUSIONS

Significant correlations between features of vegetative autonomic function represented by Ewing's 5 SCRTs and specific LA functions represented by 3DSTE-derived LA volume-based functional properties and strains could be demonstrated in healthy adults.

Echocardiographic evaluation of the right atrial size and function: Relevance for clinical practice

Right atrial (RA) structural and functional evaluations have recently emerged as powerful biomarkers for adverse events in various cardiovascular conditions. Quantitative analysis of the right atrium, usually performed with volume changes or speckle-tracking echocardiography (STE), has markedly changed our understanding of RA function and remodeling. Knowledge of reference echocardiographic values and measurement methods of RA volumes and myocardial function is a prerequisite to introduce RA quantitation in the clinical routine. This review describes the methodology, benefits and pitfalls of measuring RA size and function by echocardiography based on the current understanding of right atrial anatomy and physiological function and provides the current knowledge of right atrial function in related cardiac diseases.

Normal reference values of tricuspid annular dimensions and functional properties in healthy adults using three-dimensional speckle-tracking echocardiography (insights from the MAGYAR-Healthy Study)

Background

Three-dimensional speckle-tracking echocardiography (3DSTE) is a relatively new non-invasive imaging modality with ability for simultaneous chamber quantifications and determination of valvular dimensions. The aim of the present retrospective cohort study was to determine normal reference values of 3DSTE-derived tricuspid annular (TA) dimensions and functional properties and to evaluate their age- and gender dependency.

Methods

The present study comprised 156 healthy adult subjects, from which 28 cases were excluded due to inferior image quality, therefore the remaining group consisted of 128 cases with the mean age of 35.4±12.5 years (72 males). The subject population was further divided into the following categories: 18-29 years (n=57; mean age: 25.2±2.8 years, 51 males), 30-39 years (n=29; mean age: 34.1±2.5 years, 31 males), 40-49 years (n=17; mean age: 44.1±3.2 years, 11 males) and ≥50 years of age (n=25, mean age: 59.2±6.4 years, 14 males).

Results

End-diastolic TA diameter (2.2±0.3 vs. 2.5±0.3 cm, P<0.05), area (7.1±1.3 vs. 8.1±1.7 cm², P<0.05) and perimeter (10.3±0.9 vs. 11.0±1.2 cm, P<0.05) were lower in females than in males in the 18-29 year-old group and TA area (6.1±0.8 vs. 8.0±1.2 cm², P<0.05) and TA perimeter (9.7±0.8 vs. 11.0±0.9 cm, P<0.05) were lower in females than in males in the 40-49 year-old group. End-systolic TA diameter were lower in females than in males in the 18-29 year-old group (1.8±0.2 vs. 1.9±0.3 cm, P<0.05) and TA area (4.7±0.3 vs. 6.3±1.2 cm², P<0.05) and TA perimeter (8.6±0.4 vs. 9.5±0.9 cm, P<0.05) were lower in females than in males in the 40-49 year-old group. TA fractional area change was found to be reduced in the 40-49 year-old group as compared to the 30-39 year-old group (21.7%±8.7% vs. 29.2%±10.0%, P<0.05).

Conclusions

3DSTE is a novel method for non-invasive assessment of TA dimensions and functional properties. Results highlight the importance of age- and gender-specific reference values in case of TA diameter, area and perimeter and calculated functional features respecting the cardiac cycle.

Update on Atrial Shunt Therapy for Treatment of Heart Failure

Heart failure with preserved ejection fraction is associated with elevated left atrial pressure during exercise. Sodium-glucose cotransporter-2 inhibitors have demonstrated the evidence of benefit in heart failure with preserved ejection fraction, but even with this treatment, heart failure hospitalizations remain high, and improvements in quality of life scores are modest. Thus, there is growing interest in nonpharmacological methods of limiting the rise in left atrial pressure during exertion. Creation of an interatrial shunt (IAS) may unload the left heart during exercise. Multiple implant or nonimplant IAS procedures are under investigation. Implantation of the most studied device results in 3 to 5 mm Hg decreases in pulmonary capillary wedge pressure during exercise, no increase in incidence of stroke, stable increases in Qp/Qs (1.2-1.3), and mild right heart enlargement without change in function out to at least a year after treatment. The findings from the first large randomized controlled trial of an atrial shunt have recently been published. For the population as a whole, implantation of the atrial shunt device appeared to be safe but did not provide clinical benefit. However, prespecified and post-hoc analyses have demonstrated that men, patients with larger right atrial volumes, and those with pulmonary artery systolic pressure >70 mm Hg at 20 W exercise had worse outcomes with IAS therapy, whereas those with peak exercise pulmonary vascular resistance <1.74 Wood units and absence of a pacemaker represented a potential responder group. Here, we summarize the results of the published data and the current IAS therapies under investigation. We also highlight unanswered questions in this field of inquiry.

Effect of Bi-Atrial Size and Function in Patients With Paroxysmal or Permanent Atrial Fibrillation

Atrial fibrillation (AF) remains the most common arrhythmia in clinical practice. The choice between a rate-control and rhythm-control strategy depends on various factors, including the anatomical and functional substrate. This study investigates the anatomical and functional characteristics of both atria in patients with AF and explores the potential therapeutic implications. From an ongoing registry of patients with paroxysmal or permanent AF, those who underwent cardiac computed tomography (CCT) were included. Left atrial (LA) and right atrial (RA) sizes were measured on CCT, whereas bi-atrial function was quantified with speckle tracking strain echocardiography. The mean LA volume index was 41.6 ± 5.6 ml/m², and the mean RA volume index was 71.0 ± 21.6 ml/m². Mean LA reservoir strain was 24.3 ± 15.1%, compared with the mean RA reservoir strain of 21.6 ± 13.2%. Patients with smaller LA volumes had higher LA reservoir strain values than those with larger LA volumes (24.6% [interquartile range (IQR) 15.8 to 35.8] vs 16.5% [IQR 11.2 to 25.0], p <0.001). Patients with permanent AF had larger LA volumes (44.0 [IQR 33.7 to 55.2] ml/m² vs 36.9 [IQR 30.1 to 47.1] ml/m², p = 0.025) compared with paroxysmal AF. Patients with permanent AF had more impaired LA reservoir strain (15.5% [IQR 11.6 to 22.7] vs 26.9% [IQR 17.4 to 35.6], p <0.001) compared with paroxysmal AF. Similar trends were observed in the RA. In conclusion, atrial substrate characterization by CCT and speckle tracking strain echocardiography may have therapeutic implications, especially for choosing between a rate-control and rhythm-control strategy.

Normal ranges of left atrial volumes and ejection fraction by 3D echocardiography in adults: a systematic review and meta-analysis

Increased sizes and dysfunction of the left atrium have been related to adverse outcomes. 3D-echocardiography is more accurate than 2D-echocardiography in estimating LA volumes and ejection fraction. However, the use of 3DE for LA analysis is limited by the absence of established reference values. We performed a systematic review and meta-analysis to provide reference ranges of LA maximum and minimum volumes indexed for body surface area (LAVi max and LAVi min, respectively), and LA-EF assessed by 3DE in healthy adults. Data search was conducted from inception through September 15, 2021, using the following Medical Subject Heading terms: left atrial/atrium, three-dimensional/3D echocardiography. The study protocol was registered in the PROSPERO database (CRD42021252428). 15 studies including 4,226 healthy adults (51% males) and reporting 3DE values of LAVi max, LAVi min and LA-EF were selected. LAVi max, LAVi min and LA-EF mean and reference values were equal to 25.18 ml/m2 (95% CI 23.10, 27.26), 11.10 ml/m2 (10.01, 12.18) and 55.94% (51.92, 59.96), respectively. No influential studies were identified. Pooled estimates per age group- and sex were also estimated. By meta-regression analyses, we identified variability in LA volumes and LA-EF depending on participants' age, ethnicity and number of heart cycles at 3D multi-beat acquisition. At individual patient data analysis conducted on 374 subjects, a software effect on LA-EF was shown. This systematic review and meta-analysis provides reference values of LAVi max, LAVi min and LA-EF assessed by 3DE in healthy adults, encouraging 3DE evaluation of the LA evaluation in daily practice.

A systematic review and meta-analysis of the normal reference value of the longitudinal left atrial strain by three dimensional speckle tracking echocardiography

The normal reference value of the global longitudinal left atrial strain during the reservoir phase (LASr) by 3D speckle-tracking echocardiography (3DSTE) is needed to define the abnormal and normal spectra and to compare and interpret the obtained values. The present study is a meta-analysis of 3DSTE-derived normal reference value of the longitudinal LASr and an attempt to determine probable contributing factors in the variations of reported ranges. The databases of PubMed, Scopus, and Embase were searched for the following keywordS: "Left atrial/left atrium" and "strain/speckle/deformation" and "three-dimensional/3-dimensional/three dimensional/3 dimensional/three dimension/3 dimension/three-dimension/3-dimension/3D/3-D". The studies selected included those on adult healthy subjects without cardiovascular risk factors. A random-effect model was used to calculate the global 3DSTE-derived longitudinal LASr, and meta-regression was applied to determine inter-study heterogeneity. Our search yielded 316 adult subjects from 5 studies. The mean value of the global 3DSTE-derived longitudinal LASr was 27.5% (95% CI, 25.2-29.8%). There was significant heterogeneity between the studies. The meta-regression analysis revealed the publication year, the heart rate, and systolic and diastolic blood pressure as the sources of heterogeneity. The current meta-analysis determined a normal reference value of the global 3DSTE-derived longitudinal LASr of 27.5% (95% CI, 25.2-29.8%). The heterogeneity between studies may be explained by the publication year, the heart rate, and systolic and diastolic blood pressure.

Cardiac Imaging for the Assessment of Left Atrial Mechanics Across Heart Failure Stages

The left atrium (LA) is emerging as a key element in the pathophysiology of several cardiac diseases due to having an active role in contrasting heart failure (HF) progression. Its morphological and functional remodeling occurs progressively according to pressure or volume overload generated by the underlying disease, and its ability of adaptation contributes to avoid pulmonary circulation congestion and to postpone HF symptoms. Moreover, early signs of LA dysfunction can anticipate and predict the clinical course of HF diseases before the symptom onset which, particularly, also applies to patients with increased risk of HF with still normal cardiac structure (stage A HF). The study of LA mechanics (chamber morphology and function) is moving from a research interest to a clinical application thanks to a great clinical, prognostic, and pathophysiological significance. This process is promoted by the technological progress of cardiac imaging which increases the availability of easy-to-use tools for clinicians and HF specialists. Two-dimensional (2D) speckle tracking echocardiography and feature tracking cardiac magnetic resonance are becoming essential for daily practice. In this context, a deep understanding of LA mechanics, its prognostic significance, and the available approaches are essential to improve clinical practice. The present review will focus on LA mechanics, discussing atrial physiology and pathophysiology of main cardiac diseases across the HF stages with specific attention to the prognostic significance. Imaging techniques for LA mechanics assessment will be discussed with an overlook on the dynamic (under stress) evaluation of the chamber.

[Significance of the echocardiographic evaluation of left atrial myocardial strain for early diagnosis of heart failure with preserved ejection fraction]

This systematic review is based on 19 studies from Elsevier, PubMed, Embase, and Scopus databases, which were found by the following keywords: LA strain (left atrial strain), STE (speckle tracking echocardiography), HF (heart failure), and HFpEF (heart failure with preserved ejection fraction). The review focuses on results and conclusions of studies on using the 2D echocardiographic evaluation of left atrial (LA) myocardial strain for early diagnosis of HFpEF in routine clinical practice. Analysis of the studies included into this review showed a significant decline of all LA functions in patients with HFpEF. Also, multiple studies have reported associations between decreased indexes of LA strain and old age, atrial fibrillation, left ventricular hypertrophy, left and right ventricular systolic dysfunction, and LV diastolic dysfunction. Thus, the review indicates significant possibilities of using indexes of LA strain in evaluation of early stages of both systolic and diastolic myocardial dysfunction. Notably, LA functional systolic and diastolic indexes are not sufficiently studied despite their growing significance for diagnosis and prognosis of patients with HFpEF. For this reason, in addition to existing models for risk stratification in this disease, including clinical characteristics and/or echocardiographic data, future studies should focus on these parameters.

Contemporary narrative review on left atrial strain mechanics in echocardiography: cardiomyopathy, valvular heart disease and beyond

Left atrial (LA) strain mechanics refer to the measurement of LA myocardial deformation expressed as a percentage, and have been gathering interest over the last decade with expanding research supporting their utility in multiple cardiovascular disorders. Measured through advanced dynamic imaging techniques which include tissue Doppler imaging (TDI) and two-dimensional (2D) speckle tracking echocardiography (STE), LA strain mechanics are affected by left ventricular diastolic dysfunction prior to the onset of functional and structural changes in the left ventricle (LV). There is a need for practising cardiologists to become more familiar with the clinical utility of LA strain mechanics. In this article, we begin by reviewing the physiologic function of the LA, using this as a basis for understanding LA strain mechanics. The focus of this review article is to provide a contemporary update on the utility of LA strain mechanics in a range of cardiovascular disorders, including atrial fibrillation (AF), hypertrophic cardiomyopathy (HCM), valvular pathologies, coronary artery disease (CAD) as well as systemic diseases, such as hypertension (HTN), obesity and diabetes mellitus (DM). This article also highlights the current limitations in more widespread clinical applications of LA strain mechanics, as well as outlining the future perspectives on the clinical applications of LA strain mechanics.

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.

Reliability of left atrial strain reference values: A 3D echocardiographic study

Background

Standard apical four-chamber and two-chamber views often maximize the long-axis of the left ventricle, resulting in artifactitious foreshortening of the left atrium (LA), which may overestimate LA longitudinal reservoir strain (LALS). We compared LALS values between 2D echocardiography (2DE) and 3D echocardiography (3DE) in healthy subjects to determine whether 2DE speckle tracking analysis overestimates the reference value of LALS.

Methods and results

In this study, 4 types of cohorts were included: 1. 105 normal subjects (retrospectively), 2. 53 patients with cardiovascular diseases (retrospectively), 3. 15 patients who received cardiac magnetic resonance (prospectively), and 4. 20 normal subjects (prospectively). LALS and LA length were measured using both 2DE and 3DE in 105 healthy subjects (median age: 42 years). Biplane LALS was measured in apical four- and two-chamber views using 2DE speckle tracking software, and 3DE LALS was measured using new 3DE LA strain software. To determine sensitivity, we also performed the same analysis in 53 patients with cardiovascular disease. The mean value of biplane LALS was 39.6%. LA length at both end-diastole (r = -0.43) and end-systole (r = -0.54) was negatively correlated with biplane LALS. Multivariate regression analysis revealed that both end-diastolic and end-systolic LA length had significant negative relationships with biplane LALS after adjusting for anthropometric and echocardiographic image quality parameters. 3DE LALS (23.7±7.6%) gave significantly lower values than 2DE LALS (39.5±12.0%, p<0.001) with a weak correlation (r = 0.33). LA length measured by 2DE was significantly shorter than that measured by 3DE. The same trend was observed in diseased patients.

Conclusions

Our results revealed that in 2DE, the LA cavity consistently appears longitudinally foreshortened in apical views, potentially overestimating LALS. 3DE may overcome this limitation.

Current clinical applications of speckle tracking echocardiography for assessment of left atrial function

Two-dimensional speckle tracking echocardiography (2D-STE) enables assessment of left atrial (LA) function with better reproducibility and less load dependence than those with conventional methods. Data regarding LA functions determined by 2D-STE in patients with various cardiovascular diseases have recently been accumulating. LA strain has emerged as a novel parameter with the potential of improving the diagnostic accuracy of left ventricular diastolic dysfunction and the prognostic value in patients with heart failure and stroke. Furthermore, LA dysfunction determined by 2D STE can provide incremental prognostic information to conventional echocardiographic parameters in patients with cardiovascular diseases. Hence, 2D-STE appears to be a promising technique for diagnosis and therapeutic decision-making. Data regarding LA functions determined by three-dimensional speckle tracking echocardiography (3D-STE) have also been accumulating. Here, I review recent studies, especially those published after 2016, on clinical applications of LA function assessed by 2D-STE and 3D-STE and summarize the remaining problems to be solved for improving the clinical utility of these techniques.

Normal reference values of three-dimensional speckle-tracking echocardiography-derived mitral annular dimensions and functional properties in healthy adults: Insights from the MAGYAR-Healthy Study

INTRODUCTION

There is a limited number of echocardiographic studies determining mitral annular (MA) dimensions in healthy subjects. The present study aimed to establish normal reference values of three-dimensional speckle-tracking echocardiography-derived MA dimensions and functional properties in healthy adults in relation with age and gender.

METHODS

The present study comprised 298 healthy adult subjects. From this population, 94 subjects were excluded due to inadequate image quality. Therefore the remaining group consisted of 204 subjects with the mean age of 33.88 ± 12.97 years (107 males). The population sample was further divided into age categories: 18-29 years (n = 105; mean age: 24.11 ± 2.98 years, 51 males), 30-39 years (n = 44; mean age: 33.80 ± 2.39 years, 31 males), 40-49 years (n = 19; mean age: 43.47 ± 3.18 years, 11 males) and ≥50 years of age (n = 36, mean age: 57.42 ± 6.11 years, 14 males).

RESULTS

End-diastolic MA dimensions did not change significantly during the decades. End-systolic MA diameter, area, and perimeter were larger over the age of 50 years than in the 18-29 year-old group. MA fractional area change was found smaller over the age of 50 years than in 18-29-year-old group. While end-diastolic MA variables did not show gender-differences, end-systolic MA area and perimeter were lower in females in the 18-29-year-old group.

CONCLUSIONS

End-systolic MA dimensions change over decades, resulting in a special pattern of MA functional properties with significant reduction over the age of 50 years.

References Values for Left Atrial Volumes, Emptying Fractions, Strains, and Strain Rates and Their Determinants by Age, Gender, and Ethnicity: The Multiethnic Study of Atherosclerosis (MESA)

RATIONALE AND OBJECTIVES

Left Atrial (LA) adverse remodeling is an important predictor of morbidity and mortality in several cardiovascular (CV) diseases. Our goals were to quantify and provide reference ranges for LA structure and function using feature tracking cine cardiac magnetic resonance.

MATERIALS AND METHODS

2526 participants of the Multiethnic Study of Atherosclerosis study who had feature tracking cine cardiac magnetic resonance derived LA data and were free of atrial fibrillation/flutter and prior CV events at year five follow-up examination (2010-2012) were included in this study. LA phasic indexed volumes: maximum (LAVi max), minimum (LAVi min), and preatrial contraction (LAVi preA); LA empty fractions: total, passive, and active (LAtEF, LApEF, and LAaEF); LA longitudinal strain: maximum and preatrial contraction (S max and S preA); and LA longitudinal strain rate: systolic (SR max) and early/late diastolic (SR e and SR a) were measured. Age, gender, and race/ethnicity-specific reference ranges were identified. Also, reference values in a select subgroup of healthy participants free of traditional CV risk factors at the time of exam date were reported.

RESULTS

The mean ± SD for LAVi max, LAVi min, LAVi preA, S max, SR e, and SR a were in the 45-65-year-old participants: (33.8 ± 10 mL/m²), (14.5 ± 6.4 mL/m²), (24.8 ± 8.2 mL/m²), (34.6 ± 13.8 %), (-1.4 ± 0.7 s^-1), (-2.1 ± 1 s^-1) and in the ≥ 65-year-old participants: (35 ± 11.5 mL/m2), (16.6 ± 8.3 mL/m2), (27.6 ± 9.9 mL/m2), (31.2 ± 14.3 %), (-1 ± 0.6 s^-1), (-2.1 ± 1 s^-1) respectively. Younger individuals had Powered by Editorial Manager and ProduXion Manager from Aries Systems Corporation smaller LA volumes and better LA function compared to their older counterparts. Similar findings were observed in Chinese-Americans as compared to Whites.

CONCLUSION

This study provides reference values of LA structure and function parameters from a healthy multiethnic community-based population aged 53-94 years evaluated by FTMRI.

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

INTRODUCTION

The present study was designed to define normal reference values of three-dimensional speckle-tracking echocardiography (3DSTE)-derived left atrial (LA) volumes, stroke volumes (SVs), and emptying fractions (EFs) with regard to the cardiac cycle.

METHODS

The present study involved 256 healthy adult subjects in sinus rhythm who underwent complete two-dimensional Doppler echocardiography and 3DSTE at the same time. However, due to inferior image quality, 87 subjects have been excluded. The remaining population sample comprised of 169 patients who gave informed consent to participate in the study.

RESULTS

While systolic maximum LA volume and early diastolic preatrial contraction LA volume did not change over age decades, late-diastolic minimum LA volume decreased and was lowest in subjects aged 40 to 49 years then increased after 50 years. Total atrial EF increased over age decades with a reduction after 50 years. Passive atrial EF showed a significant continuous increase over age decades. Active atrial EF did not change in younger ages and was the highest between ages 40 and 49 years with a significant impairment after 50 years.

CONCLUSIONS

This study shows the age- and gender-dependency of normal values of 3DSTE-derived LA volumes, stroke volumes, and emptying fractions with regard to the cardiac cycle in healthy adult subjects.

Normal reference values of right atrial strain parameters using three-dimensional speckle-tracking echocardiography (results from the MAGYAR-Healthy Study)

Classic echocardiographic methodologies offer limited opportunities in assessing right atrial (RA) morphology and function. Three-dimensional (3D) speckle-tracking echocardiography (3DSTE) is a novel imaging method with objective 3D capability in assessing volumetric and functional properties of heart chambers. Normal reference values of different 3DSTE-derived RA strains are not available, therefore the aim of this prospective study was to establish these parameters in healthy subjects. The present study comprised 295 healthy volunteers, from which 110 were excluded due to inadequate image quality. The final population consisted of 185 healthy subjects in the present study (mean age: 32.1 ± 12.2 years, 89 males). Complete two-dimensional echocardiography and 3DSTE have been performed in all cases. While radial strain (RS) does not change significantly over the years in males, in female subjects it increases with age most significantly between at the age of 40–49, and it starts to decline at the age of 50 in females. While females have higher circumferential (CS) and area (AS) strain values, CS and AS decrease with age in both gender. While LS remains almost unchanged in females until ages 40–49 years with a decline above the age of 50, it decreases over the decades in males. 3D strain (3DS) increases with age in both gender, but almost doubles in females in older ages. Specific pattern of strains at atrial contraction could also be demonstrated. 3DSTE-derived RA normal reference values with age-, gender-dependency and regional values are demonstrated in a healthy population.