Functional assessment of the left atrium by real-time three-dimensional echocardiography using a novel dedicated analysis tool: initial validation studies in comparison with computed tomography

Anthracycline Treatment and Left Atrial Function in Children: A Real-Time 3-Dimensional Echocardiographic Study

Anthracycline (AC) therapy is associated with left ventricular (LV) dysfunction. Left atrial (LA) size and function are used to assess LV diastolic function in heart failure in adults. Data on LA size and function following AC therapy in children is limited. We hypothesized that LA size and function will be abnormal in children following AC chemotherapy. This retrospective review included patients who received AC for pediatric cancers. Controls had normal echocardiograms performed for evaluation of chest pain, murmur, or syncope. Real-time three-dimensional echocardiography was performed to evaluate LA reservoir, conduit, and booster pump function parameters. In addition to LA volume data, LV shortening fraction, spectral and tissue Doppler variables assessing diastolic function as well as myocardial performance index was obtained. Groups with and without AC therapy were compared by student t-test and chi-square test. We evaluated 136 patients, 55 (40.4%) had received AC. There was no significant difference between the groups in LV shortening fraction, diastolic as well as global function indices. LA reservoir and conduit function parameters were significantly lower in AC group compared to controls. The booster function parameters showed variable results. It is intriguing that AC-treated children have smaller LA reservoir and abnormal booster function. We speculate that these findings may reflect early changes in LA compliance associated with AC exposure. Assessment of LA volumes and function as prognostic markers of AC-induced cardiotoxicity in children is warranted.

Echocardiographic Measurement of Left Atrial Strain - A Key Requirement in Clinical Practice

Unlike the left ventricle (LV), the left atrium (LA) has a thin-walled structure and has been regarded as a simple conduit chamber. However, the unique function of the LA to modulate LV filling has recently drawn much attention. Because LA structure and function are directly influenced by the LV filling pressure, LA assessment is an essential step in the diagnosis of diastolic dysfunction that can help predict new-onset atrial fibrillation, assess the risk of further embolic events, and identify high-risk patients for adverse cardiovascular events. Even in the recent era of multimodality imaging, 2-dimensional (2D) echocardiography is the most common imaging method and the central modality for evaluation of LA function. LA strain derived from 2D echocardiography can help assess LA function objectively and demonstrates the 3 distinct phasic motions of the LA cycle. Further, LA strain provides invaluable pathophysiologic information and helps to predict clinical prognosis in various cardiovascular diseases. In this review article, we focus on LA strain: basic concepts, advantages over conventional parameters, and some unresolved issues. Additionally, we present a brief history of the clinical evidence for LA strain. Through this review, we suggest echocardiography for LA strain assessment in clinical practice.

Variability of echocardiographic measures of left ventricular diastolic function. The HUNT study

OBJECTIVE

Investigate variability related to image acquisition and reading process for echocardiographic measures of left ventricular (LV) diastolic function, and its influence on classification of LV diastolic dysfunction (LVDD).

METHODS

Forty participants (19 women) mean age 62 (28-88) years underwent echocardiographic examinations twice by different echocardiographers and blinded analyses by four readers in a cross-sectional design. Measurements included quantification of two- (2D) and three-dimensional (3D) recordings of the left atrium (LA) (maximal) volume (LAV_max ) and spectral Doppler blood flow and tissue velocities for assessment of LV diastolic function. Variability and reproducibility measures were calculated using variance component analyses and Kappa statistics.

RESULTS

Image acquisition influenced variability more than image reading (mean 24% and 4% of variance, respectively), but variability from image reading was especially important for 2D LAV_max (16% of variance) compared to 4% for 3D LAV_max , which was reflected in better agreement for 3D measures. The variability of measures used in classification of LVDD had clinical significance, and agreement across the four raters in classification using current recommendations was only fair (Kappa 0.42), but the agreement improved when using 3D LAV_max (Kappa 0.58). Agreement and reliability measures were reported for all measures.

CONCLUSION

Performing a new image acquisition influenced variability more than a introducing a new image reader, but there were differences across the different measures. LAV_max by 3D is superior to 2D with respect to lower variability. The variability of diastolic measures influences the reliability of LVDD classification, and this should be taken into account in the everyday clinic.

A predictive model using left atrial function and B-type natriuretic peptide level in predicting the recurrence of early persistent atrial fibrillation after radiofrequency ablation

Aim

A predictive model using left atrial function indexes obtained by real‐time three‐dimensional echocardiography (RT‐3DE) and the blood B‐type natriuretic peptide (BNP) level was constructed, and its value in predicting recurrence in patients with early persistent atrial fibrillation (AF) after radiofrequency ablation was explored.

Methods

A total of 228 patients with early persistent AF who were scheduled to receive the first circular pulmonary vein ablation (CPVA) were enrolled. Clinical data of patients were collected: (1) The blood BNP level was measured before radiofrequency ablation; (2) RT‐3DE was used to obtain the left atrial (LA) time‐volume curve; (3) The clinical characteristics, BNP level and LA function parameters were compared, and logistic regression was used to construct a prediction model with combined parameters; (4) The receiver operating characteristic (ROC) curve was used to examine the diagnostic efficacy of the model.

Results

(1) 215 patients with early persistent AF completed CPVA and the follow‐up. After 3–6 months of follow‐up, the patients were divided into sinus rhythm group (160 cases) and recurrence group (55 cases); (2) The recurrence group showed higher minimum LA volume index, diastolic ejection index, and preoperative BNP (all p ≤ .001), while the sinus rhythm group exhibited higher expansion index (PI) and left atrial appendage peak emptying velocity (p ≤ .001); (3) In univariate analysis, BNP level had the best diagnostic performance in predicting the recurrence of AF(AUC = 0.703). We constructed a model based on LA function and BNP level to predict the recurrence of persistent AF after CPVA. This combined model was better than BNP alone in predicting the recurrence of persistent AF after CPVA (AUC: 0.814 vs. 0.703, z = 2.224, p = .026).

Conclusion

The combined model of LA function and blood BNP level has good predictive value for the recurrence of early persistent AF after CPVA.

Reference ranges ("normal values") for cardiovascular magnetic resonance (CMR) in adults and children: 2020 update

Cardiovascular magnetic resonance (CMR) enables assessment and quantification of morphological and functional parameters of the heart, including chamber size and function, diameters of the aorta and pulmonary arteries, flow and myocardial relaxation times. Knowledge of reference ranges ("normal values") for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. Compared to the previous version of this review published in 2015, we present updated and expanded reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques. Further, databases and references for deep learning methods are included.

Three-Dimensional Echocardiography in Evaluating LA Volumes and Functions in Diabetic Normotensive Patients without Symptomatic Cardiovascular Disease

Background

Cardiovascular complications are the most serious threat to diabetic patients. Associated metabolic and microvascular changes are the main cause of cardiac function affection, and the earliest cardiac change is diastolic dysfunction. Assessment of LA function changes is a key to determine early heart damage of diabetic patients.

Objectives

To evaluate the effect of diabetes mellitus on left atrial volumes and functions by using real-time 3-dimensional echocardiography in normotensive patients free from cardiovascular disease.

Methods

The study included 110 individuals, 50 controls and 60 patients with diabetes mellitus, 30 patients with type 1 diabetes mellitus and 30 patients with type 2 diabetes mellitus. 2-dimensional echocardiography was used to assess the LA maximum volume and LA phasic volumes, and LA maximum volume indexed to body surface area were measured by 3D echocardiography. LA functions (LA total stroke volume, LA active stroke volume, and LA active emptying fraction) were obtained from RT3D volumetric analysis.

Results

The results of the analysis revealed that type 2 diabetes mellitus showed enlarged V _max, V _min, and LAVi with an increased LA total stroke volume and decreased active emptying fraction, while type 1 diabetics showed only decreased in active emptying fraction. The LA maximum volume indexed to body surface area (LAVi) was significantly higher in type 2 diabetic patients as compared to normal controls which was 23.55 ± 3.37 ml/m² versus 20.30.

Conclusion

Patients with type 2 diabetes mellitus have an increased LA volume with impaired compliance and contractility, while patients with type 1 diabetes mellitus have only impaired contractility compared to nondiabetic subjects.

Impact of Arterial Hypertension on Left Atrial Size and Function

An increase in left atrial (LA) size in patients with arterial hypertension (AHT) has long been known to be associated with worse cardiovascular morbidity and mortality contributes to various complications, including atrial arrhythmias, stroke, and heart failure. The aim of our study was to evaluate the impact of arterial hypertension (AHT) on the LA size and function. This cross-sectional investigation included one hundred patients with essential hypertension without valvular or structural heart disease and atrial fibrillation. All recruits had a transthoracic echocardiography. LA volumes were measured by area-length method in transthoracic echocardiography at different cardiac cycle times. The indices of LA function were calculated: the reservoir function (total emptying fraction, total emptying volume, and expansion index), the conduit function (passive emptying fraction and passive emptying volume), and the pump function (active emptying fraction and active emptying volume). For all statistical tests, a p value ≤0.05 (represents the degree of significance) is considered statistically significant. In univariate analysis, LA was dilated in 9% of patients. The LA reservoir function and the pump function were increased, respectively, in 85% and 82% of patients. LA conduit function was impaired in 80% of patients. In bivariate analysis, the most powerful factors for this repercussion were diabetes (LA volume MAX dilated in nondiabetic patients (p = 0.037)), obesity (the reservoir function was impaired in obese patients (p = 0.015)), and antihypertensive drugs (the reservoir function was impaired in patients who take beta blockers (p = 0.023); the LA pump function was significantly impaired in patients treated with calcium antagonists (p = 0.012)). This study proved the impact of AHT on the LA size and function. Further investigations are necessary to evaluate the potential predictive value of LA remodeling in hypertensive patients like speckle tracking imaging.

Real-time three-dimensional echocardiography predicts cardiotoxicity induced by postoperative chemotherapy in breast cancer patients

BACKGROUND

The anthracycline chemotherapeutic drugs are cardiotoxic. Studies have found some indicators related to cardiotoxicity. However, there is currently no accurate indicator that can predict cardiac toxicity early.

AIM

To explore the diagnostic value of real-time three-dimensional echocardiography (RT3DE) in predicting cardiac toxicity in breast cancer patients undergoing chemotherapy.

METHODS

Female breast cancer patients who underwent radical mastectomy and postoperative chemotherapy at the Affiliated Hanzhou First People’s Hospital, Zhejiang University School of Medicine were recruited. All patients were routinely administered with chemotherapy for four cycles (T1-T4) after surgery. Two-dimensional (2D) echocardiography, RT3DE, and serological examinations were performed after each cycle of chemotherapy. Patients were divided into a toxic group and a non-toxic group based on whether patients had Δ left ventricular ejection fraction > 10% after one year of chemotherapy. Repeated measurement analysis of variance was used to compare the changes in 2D echocardiographic indicators, serological indicators, and RT3DE indicators before and after chemotherapy. Multivariate logistic regression was used to identify independent predictive indicators for cardiac toxicity in postoperative chemotherapy patients. Receiver operating characteristics (ROC) curve analysis was performed to analyze the diagnostic value of potential indicators in the diagnosis of cardiotoxicity.

RESULTS

A total of 107 female breast cancer patients were included in the study. T4 maximum peak velocity in early diastole (E peak)/mitral annulus lateral tissue Doppler (e' peak) (E/e'), serological indicators [T4 cardiac troponin I (cTnI) and T4 pro-brain natriuretic peptide (Pro-BNP)], T3 minimum left atrial volume (LAV), T4 LAVmin, T3 LAV before the start of the P wave (LAVprep), and T4 LAVprep in the toxicity group were significantly higher than those in the non-toxic group. Multivariate logistic regression found that T4 cTnI, T4 Pro-BNP, T3 LAVmin, T4 LAVmin, T3 LAVprep, and T4 LAVprep had potential predictive value for cardiac toxicity (P < 0.05). ROC results showed that T4 LAVmin had the highest accuracy for diagnosing cardiac toxicity [area under the curve (AUC) = 0.947; sensitivity = 78.57%; specificity = 94.62%], followed by T4 LAVprep (AUC = 0.899; sensitivity = 100%; specificity = 66.67%). The accuracies of LAVprep and LAVprep in predicting cardiac toxicity were higher than those of T3 LAVmin and T3 LAVprep.

CONCLUSION

RT3DE of left atrial volume can be used to predict the cardiotoxicity caused by chemotherapy, and it is expected to guide the clinical adjustment of dose and schedule in time.

Atrial Myopathy

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The authors discuss the concept of atrial myopathy; its relationship to aging, electrophysiological remodeling, and autonomic remodeling; the interplay between atrial myopathy, AF, and stroke; and suggest how to identify patients with atrial myopathy and how to incorporate atrial myopathy into decisions about anticoagulation.

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Atrial myopathy seen in animal models of AF and in patients with AF is the result of a combination of factors that lead to electrical and structural remodeling in the atrium. Although AF may lead to the initiation and/or progression of this myopathy, the presence of AF is by no means essential to the development or the maintenance of the atrial myopathic state.

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Methods to identify atrial myopathy include atrial electrograms, tissue biopsy, cardiac imaging, and certain serum biomarkers. A promising modality is 4-dimensional flow cardiac magnetic resonance. The concept of atrial myopathy may help guide oral anticoagulant therapy in selected groups of patients with AF, particularly those with low to intermediate risk of strokes and those who have undergone successful AF ablation. This review highlights the need for prospective randomized trials to test these hypotheses.

This paper discusses the evolving concept of atrial myopathy by presenting how it develops and how it affects the properties of the atria. It also reviews the complex relationships among atrial myopathy, atrial fibrillation (AF), and stroke. Finally, it discusses how to apply the concept of atrial myopathy in the clinical setting—to identify patients with atrial myopathy and to be more selective in anticoagulation in a subset of patients with AF. An apparent lack of a temporal relationship between episodes of paroxysmal AF and stroke in patients with cardiac implantable electronic devices has led investigators to search for additional factors that are responsible for AF-related strokes. Multiple animal models and human studies have revealed a close interplay of atrial myopathy, AF, and stroke via various mechanisms (e.g., aging, inflammation, oxidative stress, and stretch), which, in turn, lead to fibrosis, electrical and autonomic remodeling, and a pro-thrombotic state. The complex interplay among these mechanisms creates a vicious cycle of ever-worsening atrial myopathy and a higher risk of more sustained AF and strokes. By highlighting the importance of atrial myopathy and the risk of strokes independent of AF, this paper reviews the methods to identify patients with atrial myopathy and proposes a way to incorporate the concept of atrial myopathy to guide anticoagulation in patients with AF.

Assessment of left atrial volume in dogs: comparisons of two-dimensional and real-time three-dimensional echocardiography with ECG-gated multidetector computed tomography angiography

INTRODUCTION

We hypothesized that real-time three-dimensional echocardiography (RT-3DE) was superior to two-dimensional echocardiography for the estimation of left atrial volume (LAV), using electrocardiographic (ECG)-gated multidetector computed tomography angiography (MDCTA) as a volumetric gold standard. The aim was to compare maximum LAV (LAV_max) and minimum LAV (LAV_min) measured by biplane area-length method (ALM), biplane method of disk (MOD) and RT-3DE with 64-slice ECG-gated MDCTA in dogs ANIMALS: The study included twenty dogs, anaesthetized for various diagnostic purposes and without evidence of cardiovascular disease.

METHODS

Left atrial volume was estimated by ALM, MOD and RT-3DE following ECG-gated MDCTA. The results were compared with LAV from MDCTA and correlations were performed. The limits of agreement (LoA) between methods were evaluated using Bland-Altman analysis and intraclass correlations. Coefficients of variation were calculated.

RESULTS

Area-length method (r = 0.79 and 0.72), MOD (r = 0.81 and 0.70) and RT-3DE (r = 0.94 and 0.82) correlated with MDCTA for LAV_max and LAV_min, respectively (all p < 0.05). Biases for LAV_max (-0.96 mL, 95% LoA: -5.6 to 3.7) and LAV_min (-0.67 mL, 95% LoA: -5.4 - 4.1) were minimal with RT-3DE, reflecting a slight underestimation. Conversely, MOD (LAV_maxbias = 3.19 mL, 95% LoA: -5.7 - 12.1; LAV_minbias = 1.96 mL, 95% LoA: -4.6 - 8.5) and ALM (LAV_maxbias = 4.05, 95% LoA: -5.7 - 13.8; LAV_minbias = 2.80 mL, 95% LoA: -3.9 - 9.5) suggested LAV overestimation. Intraobserver and interobserver variability were adequate.

CONCLUSIONS

Real-time three-dimensional echocardiography is a non-invasive, accurate and feasible method with superior accuracy to two-dimensional methods.

Two dimensional and real-time three dimensional ultrasound measurements of left ventricular diastolic function after marathon running: results from a substudy of the BeMaGIC trial

Strenuous exercise results in transient but minor alterations in left ventricular diastolic function (LVDF). The aim of this study is to describe and interpret the kinetics of the well-established 2D parameters of diastolic function and the novel and very sensitive 3D parameters before/after a marathon race. LVDF was evaluated by transthoracic echocardiography (TEE) in 212 healthy male [aged 42 (36-49) years)] marathon runners (all Be-MaGIC-study) in the week prior to (V1), immediately after (V2), 24 h after (V3) and 72 h after (V4) a marathon race. Real time three-dimensional echocardiography (RT3DE) included maximal and minimal left atrium (LA) volume, total LA ejection fraction (Total-EF), total LA stroke volume (Total-SV), true ejection fraction (True-EF) and atrial stroke volume (ASV). After adjustment for possible confounders (heart rate and systolic blood pressure), 2D Parameters of left ventricular inflow (E/A-ratio) decreased from pre- to immediately post-race (- 0.3 ± 0.06, p < 0.001) and returned to baseline within 24 h. [Formula: see text]-ratio remained unchanged directly post-race, but was significantly increased during follow-up of 24 and 72 h. 3D LA V_min was increased immediately postrace and in the 24 h follow-up, LA V_max was increased immediately post-race and in the follow-up of 24 and 72 h. During follow-up of 72 h, but not immediately postrace, TrueEF and ASV were significantly increased. Both techniques revealed acute and prolonged alterations of diastolic LV function. Considering all parameters, the recovery of diastolic LV after a marathon seems to take longer than previously assumed.Trial registration ClinicalTrials.gov ID: NCT00933218.

Left Atrium Wall-mapping Application for Wall Thickness Visualisation

The measurement method for the LA wall thickness (WT) using cardiac computed tomography (CT) is observer dependent and cannot provide a rapid and comprehensive visualisation of the global LA WT. We aim to develop a LA wall-mapping application to display the global LA WT on a coplanar plane. The accuracy, intra-observer, and inter-observer reproducibility of the application were validated using digital/physical phantoms, and CT images of eight patients. This application on CT-based LA WT measures were further validated by testing six pig cardiac specimens. To evaluate its accuracy, the expanded maps of the physical phantom and pig LA were generated from the CT images and compared with the expanded map of the digital phantom and LA wall of pig heart. No significant differences (p > 0.05) were found between physical phantom and digital phantom as well as pig heart specimen and CT images using our application. Moreover, the analysis was based on the LA physical phantom or images of clinical patients; the results consistently demonstrated high intra-observer reproducibility (ICC > 0.9) and inter-observer reproducibility (ICC > 0.8) and showed good correlation between measures of pig heart specimen and CT data (r = 0.96, p < 0.001). The application can process and analyse the LA architecture for further visualisation and quantification.

Association of chronic kidney disease with impaired left atrial reservoir function: A community-based cohort study

Background Chronic kidney disease (CKD) is an independent risk factor for atrial fibrillation, although the pathophysiological mechanisms remain unclear. This study investigated the relationship between CKD and left atrial (LA) volume and function in a sample of the general population without overt cardiac disease. Design and methods We examined 358 participants from the Cardiovascular Abnormalities and Brain Lesions study. The LA minimum volume index (LAVI_min), LA maximum volume index (LAVI_max), and LA emptying fraction (LAEF) were assessed by real-time three-dimensional echocardiography. Based on their estimated glomerular filtration rate (eGFR), the participants were divided into a CKD group (eGFR <60 ml/min/1.73 m²) and a non-CKD group (eGFR ≥60 ml/min/1.73 m²). Results Of the 358 participants, 69 (19%) were classified as having CKD and 289 (81%) as non-CKD. Participants with CKD were older, had a greater prevalence of hypertension and use of antihypertensive drugs, a larger left ventricular (LV) mass index, and a higher prevalence of diastolic dysfunction than those without CKD (all p < 0.05). There was no significant difference in LAVI_max between the CKD and non-CKD groups (23.4 ± 7.1 vs. 22.8 ± 5.8 ml/m², p = 0.47), whereas significant differences were observed for LAVI_min (13.6 ± 5.5 vs. 12.0 ± 4.6 ml/m², p = 0.01) and LAEF (42.7 ± 11.4 vs. 47.8 ± 11.5%, p = 0.001). Multivariate regression analysis revealed that the eGFR was significantly associated with LAEF independent of age, LV mass index, and diastolic dysfunction (all p < 0.05). Conclusions Participants with CKD in an unselected community-based cohort had significantly impaired LA reservoir function. Assessment of LA function may add important information in the prognostic assessment of patients with CKD even in the absence of overt cardiac disease.

Left ventricular diastolic function is strongly correlated with active emptying of the left atrium: a novel analysis using three-dimensional echocardiography

Background

Increased left atrial (LA) dimensions are known to be a risk factor in predicting cardiovascular events and mortality and to be one key diagnostic tool to assess diastolic dysfunction. Currently, LA measurements are usually conducted using 2D-echocardiography, although there are well-known limitations. Real-time 3D-echocardiography is able to overcome these limitations, furthermore being a valid measurement tool compared to reference standards (e.g. cardiac magnetic resonance imaging).

We investigated LA function and volume and their association to left ventricular (LV) diastolic function, using newly designed and validated software for 3D-echocardiographic analysis. This software is the first to allow for a sophisticated analysis of both passive and active LA emptying.

Methods

We analyzed 2D- and 3D-echocardiographic measurements of LA volume and function in 56 subjects and compared the results between patients with normal LV diastolic function (NDF) (n = 30, 52 ± 15 years, BMI 24.7 ± 2.6 kg/m²) and patients in which diastolic dysfunction (DDF) was suspected (n = 26, 65 ± 9 years, BMI 26.7 ± 3.7 kg/m²).

Results

Volumes during LA active emptying were significantly smaller in DDF compared to NDF (active atrial stroke volume (ASV): 3.0 (0.1–4.5) vs. 5.5 (2.7–7.8) ml, p = 0.005; True-EF: 7.3(0.1–11.5) vs. 16.2 (8.1–25.4) %, p = 0.002). Furthermore, ASV showed a stronger association to E/e’_mean than all other measured LA volumes (β = − 0.35, p = 0.008). Neither total stroke LA volume, nor maximum or minimum LA volume differed significantly between the groups.

Conclusions

Diastolic LV dysfunction results in a reduction in active LA emptying, which is more strongly associated with LV filling pressure than other previously investigated LA parameters.

Determinants of Left Atrial Volume in Patients with Atrial Fibrillation

Introduction

Left atrial (LA) enlargement is an important risk factor for incident stroke and a key determinant for the success of rhythm control strategies in patients with atrial fibrillation (AF). However, factors associated with LA volume in AF patients remain poorly understood.

Methods

Patients with paroxysmal or persistent AF were enrolled in this study. Real time 3-D echocardiography was performed in all participants and analyzed offline in a standardized manner. We performed stepwise backward linear regression analyses using a broad set of clinical parameters to determine independent correlates for 3-D LA volume.

Results

We included 210 patients (70.9% male, mean age 61±11years). Paroxysmal and persistent AF were present in 95 (45%) and 115 (55%) patients, respectively. Overall, 115 (55%) had hypertension, 11 (5%) had diabetes, and 18 (9%) had ischemic heart disease. Mean indexed LA volume was 36±12ml/m². In multivariable models, significant associations were found for female sex (β coefficient -10.51 (95% confidence interval (CI) -17.85;-3.16), p = 0.0053), undergoing cardioversion (β 11.95 (CI 5.15; 18.74), p = 0.0006), diabetes (β 14.23 (CI 2.36; 26.10), p = 0.019), body surface area (BSA) (β 34.21 (CI 19.30; 49.12), p<0.0001), glomerular filtration rate (β -0.21 (CI -0.36; -0.06), p = 0.0064) and plasma levels of NT-pro brain natriuretic peptide (NT-proBNP) (β 6.79 (CI 4.05; 9.52), p<0.0001), but not age (p = 0.59) or hypertension (p = 0.42). Our final model explained 52% of the LA volume variability.

Conclusions

In patients with AF, the most important correlates with LA volume are sex, BSA, diabetes, renal function and NT-proBNP, but not age or hypertension. These results may help to refine rhythm control strategies in AF patients.

Left-Atrial Segmentation From 3-D Ultrasound Using B-Spline Explicit Active Surfaces With Scale Uncoupling

Segmentation of the left atrium (LA) of the heart allows quantification of LA volume dynamics which can give insight into cardiac function. However, very little attention has been given to LA segmentation from three-dimensional (3-D) ultrasound (US), most efforts being focused on the segmentation of the left ventricle (LV). The B-spline explicit active surfaces (BEAS) framework has been shown to be a very robust and efficient methodology to perform LV segmentation. In this study, we propose an extension of the BEAS framework, introducing B-splines with uncoupled scaling. This formulation improves the shape support for less regular and more variable structures, by giving independent control over smoothness and number of control points. Semiautomatic segmentation of the LA endocardium using this framework was tested in a setup requiring little user input, on 20 volumetric sequences of echocardiographic data from healthy subjects. The segmentation results were evaluated against manual reference delineations of the LA. Relevant LA morphological and functional parameters were derived from the segmented surfaces, in order to assess the performance of the proposed method on its clinical usage. The results showed that the modified BEAS framework is capable of accurate semiautomatic LA segmentation in 3-D transthoracic US, providing reliable quantification of the LA morphology and function.

Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

The rapid technological developments of the past decade and the changes in echocardiographic practice brought about by these developments have resulted in the need for updated recommendations to the previously published guidelines for cardiac chamber quantification, which was the goal of the joint writing group assembled by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. This document provides updated normal values for all four cardiac chambers, including three-dimensional echocardiography and myocardial deformation, when possible, on the basis of considerably larger numbers of normal subjects, compiled from multiple databases. In addition, this document attempts to eliminate several minor discrepancies that existed between previously published guidelines.

Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

The rapid technological developments of the past decade and the changes in echocardiographic practice brought about by these developments have resulted in the need for updated recommendations to the previously published guidelines for cardiac chamber quantification, which was the goal of the joint writing group assembled by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. This document provides updated normal values for all four cardiac chambers, including three-dimensional echocardiography and myocardial deformation, when possible, on the basis of considerably larger numbers of normal subjects, compiled from multiple databases. In addition, this document attempts to eliminate several minor discrepancies that existed between previously published guidelines.

Automated quantification of left atrial size using three-beat averaging real-time three dimensional Echocardiography in patients with atrial fibrillation

Background

Left atrial (LA) sizing in patients with atrial fibrillation (AF) is crucial for follow-up and outcome. Recently, the automated quantification of LA using the novel three-beat averaging real-time three dimensional echocardiography (3BA-RT3DE) is introduced. The aim of this study was to assess the feasibility and accuracy of 3BA-RT3DE in patients with atrial fibrillation (AF).

Methods

Thirty-one patients with AF (62.8 ± 11.7 years, 67.7 % male) were prospectively recruited to have two dimensional echocardiography (2DE) and 3BA-RT3DE (SC 2000, ACUSON, USA). The maximal left atrial (LA) volume was measured by the conventional prolate-ellipse (PE) and area-length (AL) method using three-beat averaging 2D transthoracic echocardiography and automated software analysis (eSie volume analysis, Siemens Medical Solution, Mountain view, USA); measurements were compared with those obtained by computed tomography (CT).

Results

Maximal LA volume by 3BA-RT3DE was feasible for all patients. LA volume was 68.4 ± 28.2 by PE-2DE, 89.2 ± 33.1 by AL-2DE, 100.6 ± 31.8 by 3BA-RT3DE, and 131.2 ± 42.2 mL by CT. LA volume from PE-2DE (R² = 0.48, p < 0.001, ICC = 0.64, p < 0.001), AL-2DE (R² = 0.47, p < 0.001, ICC = 0.67, p < 0.001), and 3BA-RT3DE (R² = 0.50, p = 0.001, ICC = 0.65, p < 0.001) showed significant correlations with CT. However, 3BA-RT3DE demonstrated a small degree of underestimation (30.5 mL) of LA volume compared to 2DE-based measurements. Good-quality images from 3BA-RT3DE (n = 16) showed a significantly tighter correlation with images from CT scanning (R² = 0.60, p = 0.0004, ICC = 0.76, p < 0.001) compared to those of fair quality.

Conclusion

Automated quantification of LA volume using 3BA-RT3DE is feasible and accurate in patients with AF. An image of good quality is essential for maximizing the value of this method in clinical practice.

The Role of Magnetic Resonance Imaging and Cardiac Computed Tomography in the Assessment of Left Atrial Anatomy, Size, and Function

In the last decade, there has been increasing evidence that comprehensive evaluation of the left atrium is of utmost importance. Numerous studies have clearly demonstrated the prognostic value of left atrial volume for long-term outcome. Furthermore, advances in catheter ablation procedures used for the treatment of drug-refractory atrial fibrillation require the need for detailed knowledge of left atrial and pulmonary venous morphology as well of atrial wall characteristics. This review article discusses the role of cardiac magnetic resonance and computed tomography in assessment of left atrial size, its normal and abnormal morphology, and function. Special interest is paid to the utility of these rapidly involving noninvasive imaging methods before and after atrial fibrillation ablation.

Single breath-hold 3D measurement of left atrial volume using compressed sensing cardiovascular magnetic resonance and a non-model-based reconstruction approach

BACKGROUND

Left atrial (LA) dilatation is associated with a large variety of cardiac diseases. Current cardiovascular magnetic resonance (CMR) strategies to measure LA volumes are based on multi-breath-hold multi-slice acquisitions, which are time-consuming and susceptible to misregistration.

AIM

To develop a time-efficient single breath-hold 3D CMR acquisition and reconstruction method to precisely measure LA volumes and function.

METHODS

A highly accelerated compressed-sensing multi-slice cine sequence (CS-cineCMR) was combined with a non-model-based 3D reconstruction method to measure LA volumes with high temporal and spatial resolution during a single breath-hold. This approach was validated in LA phantoms of different shapes and applied in 3 patients. In addition, the influence of slice orientations on accuracy was evaluated in the LA phantoms for the new approach in comparison with a conventional model-based biplane area-length reconstruction. As a reference in patients, a self-navigated high-resolution whole-heart 3D dataset (3D-HR-CMR) was acquired during mid-diastole to yield accurate LA volumes.

RESULTS

Phantom studies. LA volumes were accurately measured by CS-cineCMR with a mean difference of -4.73 ± 1.75 ml (-8.67 ± 3.54%, r2 = 0.94). For the new method the calculated volumes were not significantly different when different orientations of the CS-cineCMR slices were applied to cover the LA phantoms. Long-axis "aligned" vs "not aligned" with the phantom long-axis yielded similar differences vs the reference volume (-4.87 ± 1.73 ml vs. -4.45 ± 1.97 ml, p = 0.67) and short-axis "perpendicular" vs. "not-perpendicular" with the LA long-axis (-4.72 ± 1.66 ml vs. -4.75 ± 2.13 ml; p = 0.98). The conventional bi-plane area-length method was susceptible for slice orientations (p = 0.0085 for the interaction of "slice orientation" and "reconstruction technique", 2-way ANOVA for repeated measures). To use the 3D-HR-CMR as the reference for LA volumes in patients, it was validated in the LA phantoms (mean difference: -1.37 ± 1.35 ml, -2.38 ± 2.44%, r2 = 0.97). Patient study: The CS-cineCMR LA volumes of the mid-diastolic frame matched closely with the reference LA volume (measured by 3D-HR-CMR) with a difference of -2.66 ± 6.5 ml (3.0% underestimation; true LA volumes: 63 ml, 62 ml, and 395 ml). Finally, a high intra- and inter-observer agreement for maximal and minimal LA volume measurement is also shown.

CONCLUSIONS

The proposed method combines a highly accelerated single-breathhold compressed-sensing multi-slice CMR technique with a non-model-based 3D reconstruction to accurately and reproducibly measure LA volumes and function.

Normal values for cardiovascular magnetic resonance in adults and children

Morphological and functional parameters such as chamber size and function, aortic diameters and distensibility, flow and T1 and T2* relaxation time can be assessed and quantified by cardiovascular magnetic resonance (CMR). Knowledge of normal values for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. In this review, we present normal reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques and sequences.

Left atrial function as assessed by speckle-tracking echocardiography in hypertension

We investigated left atrial (LA) function in relation to hypertension using 2-dimensional speckle-tracking echocardiography (STE) in subjects with preserved left ventricular (LV) ejection fraction, while accounting for LA enlargement and LV mass and diastolic function.We performed standard 2-dimensional and Doppler echocardiography and LA volumetric measurements and STE strain imaging in hypertensive patients (systolic/diastolic blood pressure ≥140/90 mmHg, or use of antihypertensive drugs, n = 124) and age- and sex-matched normotensive subjects (n = 124). We measured the peak LA velocity, strain, and strain rate during systole and early and late diastole, respectively. We investigated the associations of interests in the presence or absence of LA enlargement (LA volume index ≥28 mL/m).Hypertensive and normotensive subjects had similar LV ejection fraction and LA diameter (P ≥ 0.22). However, hypertensive compared with normotensive subjects had enlarged LV and impaired diastolic function, and had increased LA volumetric measurements and decreased LA emptying fractions (P < 0.0001). Hypertensive patients also had impaired LA function, as measured by STE velocity, strain, and strain rate in general and in the absence of LA enlargement (P < 0.0001). The differences in LA STE strain rate during LV systole and LA contraction between hypertension and normotension in the absence of LA enlargement remained statistically significant (P < 0.001), after adjustment for age, sex, and LV mass index and E/E'.Hypertension is associated with impaired LA function, as assessed by STE strain imaging technique, even before LA enlargement develops and after LV remodeling is accounted for.

Evaluation of left atrial function by real-time 3-D echocardiography in patients with systemic lupus erythematosus

OBJECTIVE

Left atrial function plays a key role in maintaining an optimal cardiac output. Left ventricular diastolic dysfunction has been reported in systemic lupus erythematosus (SLE), but its effect on left atrial function has been largely overlooked. Our aim was to assess left atrial performance using real-time 3-D echocardiography (RT3DE) technology in patients with SLE.

METHODS

Our study included 102 patients with SLE without any cardiac symptoms, and 32 healthy controls. According to the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI), all subjects were classified into 3 groups: healthy controls, patients with an SDI = 0, and patients with an SDI ≥ 1.

RESULTS

Left atrial volume indexed to body surface area was dilated in subjects with SLE, whereas the left atrial passive emptying fraction (EF) was lower. Left atrial active EF was significantly higher in the SDI = 0 group than in controls (46.4 ± 9.1% vs 30.0 ± 10.3%, p < 0.05); however, it was significantly lower in the SDI ≥ 1 group than in the SDI = 0 group (41.2 ± 9.8% vs 46.4 ± 9.1%, p < 0.05). By multivariate linear analysis, the SDI was independently and positively associated with left atrial volume index and inversely associated with left atrial total function.

CONCLUSION

Our study demonstrated that left atrial mechanical function and volume are impaired in SLE, particularly in patients with an SDI ≥ 1 and disease activity. RT3DE may have better diagnostic value than traditional echo indexes in detecting subclinical cardiac dysfunction in patients with SLE.

The influence of type 2 diabetes on left atrial remodeling

The influence of type 2 diabetes mellitus on cardiac remodeling has been evaluated for decades; however, the majority of investigations were focused only on the left ventricle. The impact of diabetes on the left atrial (LA) function is less researched. LA enlargement has been shown as an independent predictor of cardiovascular morbidity and mortality in the general and diabetic population; however, LA dysfunction has been proven to be an independent predictor only in the general population. There are not much follow-up data about the influence of diabetes on LA function. New echocardiographic techniques, such as 2-dimensional speckle tracking imaging, provide more accurate, sensitive, and reliable information about LA function than traditional, volumetric methods. The aim of this review was to summarize the most recent reports about the influence of diabetes on LA function, as well as to discuss the possible mechanisms and potential clinical implications of the relationship between diabetes and LA remodeling.

Effects of sinus rhythm maintenance on left heart function after electrical cardioversion of atrial fibrillation: implications for tachycardia-induced cardiomyopathy

BACKGROUND

The role of tachycardia-induced cardiomyopathy vs tachycardia-related short diastolic filling period and reduced atrial contraction in decline of left ventricular ejection fraction (LVEF) in atrial fibrillation (AF) is uncertain. We aimed to characterize left heart changes over time in patients with AF who undergo electrical cardioversion (ECV).

METHODS

Consecutive AF patients who were to undergo ECV were enrolled. Patients with unstable or acute heart failure, severe valvular diseases, recent open-heart surgery, major disorders, or an unsuccessful ECV were excluded. Transthoracic echocardiography, including 3-dimensional left atrial and ventricular volume acquisitions, was performed 1-2 hours before and after ECV, and 4-6 weeks later.

RESULTS

In 73 patients (77% male, 66 ± 11 years), ECV resulted in an immediate increase in LVEF (from 43 [interquartile range (IQR), 33-50%] to 48 [IQR, 40-53%]; P < 0.0001). Four to 6 weeks after ECV, ejection fraction increased further in patients who remained in sinus rhythm (SR) (n = 55) to 55 (IQR, 44-62)%; P < 0.001. In patients with AF relapse, LVEF returned to values comparable to pre-ECV (n = 18) (44 [IQR, 32-51]%; P = 0.03). The atrial emptying fraction did not significantly change immediately after ECV (n = 69; from 20 [IQR, 13-25]% to 20 [IQR, 15-28]%; P = 0.14). Only patients who remained in SR showed an increase in atrial emptying fraction after 4-6 weeks (n = 51; to 37 [IQR, 26-48]%; P < 0.0001 vs post-ECV).

CONCLUSIONS

Immediate improvement in LVEF after ECV explains approximately 50% of total LVEF increase over time. However, in SR, LVEF, and atrial function continuously increase over 4-6 weeks after ECV. This might be attributable to recovery of tachycardia-induced cardiomyopathy.