What Is the Best Approach for the Assessment of Left Atrial Size? Comparison of Various Unidimensional and Two-dimensional Parameters with Three-dimensional Echocardiographically Determined Left Atrial Volume

Increased left and right atrial volume indices are associated with decreased survival times post-cardiac arrest

BACKGROUND

Left and right atrial volume indices (LAVI and RAVI) are markers of cardiac remodeling. LAVI and RAVI are associated with worse outcomes in other cardiac conditions. This study aimed to determine the associations of these atrial volume indices with survival time post-cardiac arrest.

METHODS

This was a single center, retrospective study of patients with a sudden cardiac arrest event during index hospitalization from 2014-2018 based on pre-arrest parameters. The analysis was stratified based on whether a pulseless ventricular tachycardia/ventricular fibrillation (pVT/VF) event or a pulseless electrical activity (PEA)/asystole event occurred. Cox proportional hazards regression and model selection with best subsets approach evaluated the association of atrial volume parameters with survival times in the context of other covariates.

RESULTS

Of 305 patients studied (64 ± 14 years, 37% female), the mean LAVI was 34.0 ± 15.8 mL/m² (based on 162 reliable measurements), and mean RAVI was 25.0 ± 15.6 mL/m² (based on 163 measurements). Increased atrial volume indices were most strongly associated with survival in patients who had sustained pVT/VF (LAVI HR 0.47, 95% CI 0.25-0.90, p = 0.020; RAVI HR 0.57, 95% CI 0.30-1.05, p = 0.074). In multivariable best subsets Cox regression with LAVI, RAVI, and 13 other scaled covariates, LAVI < 34 ml/m² was by far the best single predictor of survival (p < 0.0001), and the next best predictor was the absence of pulmonary hypertension.

CONCLUSION

Among patients with cardiac arrest from ventricular arrhythmias, those with no more than mild left atrial enlargement pre-arrest by LAVI measurement had the best prognosis. Additional studies are indicated to validate the importance of this finding for clinical management decisions.

CONDENSED ABSTRACT

In patients with sudden cardiac arrest associated with ventricular arrhythmias, a left atrial volume index (LAVI) < 34 mL/m² prior to the arrest had the strongest association with survival among fifteen candidate predictors. Pulmonary hypertension was more common in patients with an elevated right atrial volume index (RAVI), and the absence of pulmonary hypertension was the next best pre-arrest parameter predictive of survival. Larger studies are indicated to validate the use of LAVI for clinical management decisions in this condition.

Identification of Circular RNA-MicroRNA-Messenger RNA Regulatory Network in Atrial Fibrillation by Integrated Analysis

BACKGROUND

Circular RNA (circRNA) is a noncoding RNA that forms a closed-loop structure, and its abnormal expression may cause disease. We aimed to find potential network for circRNA-related competitive endogenous RNA (ceRNA) in atrial fibrillation (AF).

METHODS

The circRNA, miRNA, and mRNA expression profiles in the heart tissue from AF patients were retrieved from the Gene Expression Omnibus database and analyzed comprehensively. Differentially expressed circRNAs (DEcircRNAs), differentially expressed miRNAs (DEmiRNAs), and differentially expressed mRNAs (DEmRNAs) were identified, followed by the establishment of DEcircRNA-DEmiRNA-DEmRNA regulatory network. Functional annotation analysis of host gene of DEcircRNAs and DEmRNAs in ceRNA regulatory network was performed. In vitro experiment and electronic validation were used to validate the expression of DEcircRNAs, DEmiRNAs, and DEmRNAs.

RESULTS

A total of 1611 DEcircRNAs, 51 DEmiRNAs, and 1250 DEmRNAs were identified in AF. The DEcircRNA-DEmiRNA-DEmRNA network contained 62 circRNAs, 14 miRNAs, and 728 mRNAs. Among which, two ceRNA regulatory pairs of hsa-circRNA-100053-hsa-miR-455-5p-TRPV1 and hsa-circRNA-005843-hsa-miR-188-5p-SPON1 were identified. In addition, six miRNA-mRNA regulatory pairs including hsa-miR-34c-5p-INMT, hsa-miR-1253-DDIT4L, hsa-miR-508-5p-SMOC2, hsa-miR-943-ACTA1, hsa-miR-338-3p-WIPI1, and hsa-miR-199a-3p-RAP1GAP2 were also obtained. MTOR was a significantly enriched signaling pathway of host gene of DEcircRNAs. In addition, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy, and hypertrophic cardiomyopathy were remarkably enriched signaling pathways of DEmRNAs in DEcircRNA-DEmiRNA-DEmRNA regulatory network. The expression validation of hsa-circRNA-402565, hsa-miR-34c-5p, hsa-miR-188-5p, SPON1, DDIT4L, SMOC2, and WIPI1 was consistent with the integrated analysis.

CONCLUSION

We speculated that hsa-circRNA-100053-hsa-miR-455-5p-TRPV1 and hsa-circRNA-005843-hsa-miR-188-5p-SPON1 interaction pairs may be involved in AF.

Comparative assessment of left atrial volume in healthy cats by two-dimensional and three-dimensional echocardiography

Background

The left atrium (LA) is an important prognostic parameter in cardiac pathologies of cats. Its size is currently measured in one-dimensional methods, while human medicine considers two- and three-dimensional echocardiography as standard. The objectives of this study were to compare monoplane, biplane, triplane and real-time three dimensional echocardiography for volumetric measurement of the left atrium in healthy cats and establish a reference interval for further studies on cats with heart disease. Additionally, the influence of age, sex and weight on left atrial volume (LAV) was tested.

Results

One dimensional monoplane Simpson method of discs (SMOD) in the right parasternal four chamber view (r4) and the left apical 2 chamber view (l2) as well as biplane SMOD had no significant difference for left atrial maximum volume (LAMax). They can be used as equivalent in future studies and one common reference range was set up (1.96 ± 0.54 ml). Those three methods produced significantly higher volumes than triplane echocardiography (RTTPE) and real time three dimensional echocardiography (RT3DE) using TomTec® software. LA volumetry with RTTPE and RT3DE-TomTec™ was more feasible than expected, but low RT3DE image quality was the main reason for excluding patients. Neither age nor weight had an influence on LA volume in healthy cats. Male LAV results were only slightly, but in 2D and RTTPE significantly higher than those of female cats with a range of + 10.46% to + 19.58%.

Conclusions

Monoplane, biplane, triplane and real-time three dimensional echocardiography were feasible for LA volumetry in healthy cats and showed acceptable intra- and interobserver variability. One common LAMax reference range for monoplane r4, l2 and biplane SMOD was set up. Raw data can be used for LA volumes and does not need to be correlated with the cat’s weight or age. Male cats have only slightly but significantly larger atria than females in 2D and RTTPE. Therefore, under reservation, also sex related limit values were defined.

Prevention of sudden cardiac death in hypertrophic cardiomyopathy: Risk assessment using left atrial diameter predicted from left atrial volume

Background

Left atrial diameter (LAd) is included in the European Society for Cardiology's (ESC) risk model for assessment of sudden cardiac death (SCD) risk in hypertrophic cardiomyopathy (HCM), but the recommended measure of LA size is left atrial volume (LAv).

Hypothesis

We hypothesized that LAv could be used instead of LAd in the HCM risk‐SCD model. We aimed to determine the relation between LAd and LAv and to assess the impact of using LAv instead of LAd.

Methods

Echocardiographic measurements of anteroposterior LAd in the parasternal long‐axis window and LAv from Simpson's biplane method of disks were used. The 5‐year risk of SCD by measured LAd and by LAd predicted from LAv were estimated using the ESC risk‐SCD model.

Results

In 205 HCM patients (age 56 ± 14 years, 62% male), the relation between LAd and LAv was linear. Median 5‐year risk of SCD was 2.4% (interquartile range [IQR]: 1.6; 3.8) using measured LAd and 2.4% (IQR: 1.6; 3.7) using predicted LAd. The correlation between the SCD risk assessed by measured vs predicted LAd was excellent (r² = 0.96). Use of predicted LAd resulted in four patients (2%) being recategorized between the moderate and high‐risk categories.

Conclusions

The relation between LAd and LAv was linear with good agreement. On a population level, the correlation between the risk of SCD using measured LAd or LAd predicted from LAv was excellent. On a patient level, using LAd predicted from LAv resulted in the vast majority remaining in the same risk category; however, for a minority of patients, it changed the recommendation.

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.

Importance of the Left Atrium: More Than a Bystander?

Left atrial size and function parameters are associated with adverse outcomes in multiple disease states, including heart failure with reduced and preserved ejection fraction. Recent data suggest that phasic left atrial function and left atrial stain measurements also hold prognostic information. Three-dimensional echocardiography provides more accurate and reproducible quantification of left atrial volumes than 2-dimensional echocardiography when compared with cardiac magnetic resonance reference standards. Greater accessibility to these advanced imaging techniques allows for the integration of these parameters into routine clinical practice.

Left atrial volume index: Can it provide additional prognostic information in ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention?

INTRODUCTION

We sought to assess the prognostic impact of left atrial (LA) size on long-term outcomes of ST-segment elevation myocardial infarction (STEMI).

METHODS

We studied 200 consecutive patients admitted to a single center between January 2010 and December 2014 with non-fatal STEMI treated with primary percutaneous coronary intervention (pPCI) who underwent a comprehensive echocardiographic examination at discharge. LA volume was estimated by the area-length method. The left atrium was classified as normal, mildly, moderately or severely enlarged by LA volume index (LAVI). The endpoints were defined as all-cause mortality, a cardiac composite endpoint (all-cause mortality, reinfarction, unplanned revascularization and hospitalization for heart failure) and a cardiovascular composite endpoint (cardiac endpoint plus atrial fibrillation and ischemic stroke) during follow-up.

RESULTS

In this STEMI population, 58% had normal LA size, 22.5% had mild LA enlargement, 10% had moderate LA enlargement and 9.5% had severe LA enlargement. During a median follow-up of 28 (IQR 21-38) months, 14 (7.0%) patients died, 53 (26.5%) had the cardiac and 58 (29%) the cardiovascular composite endpoints. There was a stepwise increase in the incidence of all-cause mortality (p=0.020) and both cardiac (p<0.001) and cardiovascular (p<0.001) endpoints with each increment of LAVI class. In multivariate analysis, severe LA enlargement by LAVI was an independent predictor of all-cause mortality (HR: 11.153; 95% CI: 1.924-64.642, p=0.007) and the cardiac (HR: 4.351; 95% CI: 1.919-9.862, p<0.001) and cardiovascular (HR: 4.351; 95% CI: 1.919-9.862, p<0.001) endpoints during follow-up.

CONCLUSIONS

This contemporary study confirms the prognostic effect of LA size at discharge, applying the most recent reference values in STEMI patients treated with pPCI.

Bi-Atrial Function before and after Percutaneous Closure of Atrial Septum in Patients with and without Paroxysmal Atrial Fibrillation: A 2-D and 3-D Speckle Tracking Echocardiographic Study

Our aim was to analyze atrial function with 2-D (2-D-STE) and 3-D (3-D-STE) speckle tracking echocardiography in patients with atrial septal devices and paroxysmal atrial fibrillation (PAF). One hundred sixteen patients and a subgroup of 22 patients who developed PAF after device insertion were studied. Left atrial and right atrial peak longitudinal strain and standard deviations of time to peak strain (TPS) were calculated using 2-D-STE. The left atrial/right atrial emptying fraction and expansion index were determined using 3-D-STE. By multivariate analysis, pre-closure 3-D right atrial expansion index, left atrial time to peak strain, and 3-D left atrial expansion index were independently associated with PAF. Compared with the other indices, receiver operating characteristic analysis revealed better diagnostic accuracy for the combination of pre-closure time to peak strain and 3-D expansion index in detecting PAF. Patients with atrial septal devices have pre-existing left and right atrial dilation and dysfunction as assessed by 2-D-STE and 3-D-STE that appear sensitive for the stratification of PAF risk in this population.

Assessment of electrocardiographic criteria of left atrial enlargement

Background Left atrial enlargement is considered to be a robust, strong, and widely acceptable indicator of cardiovascular outcomes. Echocardiography is the gold standard for measurement of left atrial size, but electrocardiography can be simple, cost-effective, and noninvasive in clinical practice. This study was undertaken to assess the diagnostic accuracy of an established electrocardiographic criterion for left atrial enlargement, taking 2-dimensional echocardiography as the gold-standard technique. Methods A cross-sectional study was conducted on 146 consecutively selected patients with the complaints of dyspnea and palpitation and with a murmur detected on clinical examination, from September 10, 2016 to February 10, 2017. Electrocardiography and echocardiography were performed in all patients. Patients with a negative P wave terminal force in lead V₁ > 40 ms·mm on electrocardiography or left atrial dimension > 40 mm on echocardiography were classified as having left atrial enlargement. Sensitivity and specificity were calculated to assess the diagnostic accuracy. Results Taking 2-dimensional echocardiography as the gold-standard technique, electrocardiography correctly diagnosed 68 patients as positive for left atrial enlargement and 12 as negative. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of electrocardiography for left atrial enlargement were 54.4%, 57.1%, 88.3%, 17.4%, and 54.8%, respectively. Conclusion The electrocardiogram appears to be a reasonable indicator of left atrial enlargement. In case of nonavailability of echocardiography, electrocardiography can be used for diagnosis of left atrial enlargement.

Left atrial function in patients with light chain amyloidosis: A transthoracic 3D speckle tracking imaging study

BACKGROUND

Systemic light chain amyloidosis (AL) is characterized by the extracellular deposition of amyloid fibrils. Transthoracic echocardiography is the modality of choice to assess cardiac function in patients with AL. Whereas left ventricular (LV) function has been well studied in this patient population, data regarding the value of left atrial (LA) function in AL patients are lacking. In this study, we aim to examine the impact of LA volumes and function on survival in AL patients as assessed by real-time 3D echocardiography.

METHODS

A total of 77 patients (67±10 years, 60% men) with confirmed AL and 39 healthy controls were included. All standard 2D echocardiographic and 3D-LA parameters were obtained.

RESULTS

Fourteen patients (18%) were in Mayo Clinic (MC) stage I, 30 (39%) in stage II, and 33 (43%) in stage III at initial evaluation. There was no significant difference among the MC stages groups in terms of age, gender, or cardiovascular risk factors. As compared to patients in MC II and MC I, those in MC III had significantly larger indexed 3D-LA volumes (MCIII: 46±15mL/m², MC II: 38±12mL/m², and MC I: 23±9mL/m², p<0.0001), lower 3D-LA total emptying fraction (3D-tLAEF) (21±13% vs. 31±15% vs. 43±7%, respectively, p<0.0001), and worse 3D peak atrial longitudinal strain (3D-PALS) (11±9% vs. 18±13% vs. 20±7%, respectively, p=0.007). Two-year survival was significantly lower in patients with 3D-tLAEF <+34% (p=0.003) and in those with 3D-PALS <+14% (p=0.034). Both parameters provided incremental prognostic value over maximal LA volume in multivariate analysis.

CONCLUSION

Functional LA parameters are progressively altered in AL patients according to the MC stage. A decrease in 3D-PALS is associated with worse outcome, independently of LA volume.

Echocardiographic predictors of atrial fibrillation after mitral valve replacement

Objectives

Detection of the echocardiographic predictors of post-operative atrial fibrillation in patients with rheumatic mitral valve disease undergoing mitral valve replacement.

Methods

The study included 50 patients with rheumatic mitral valve disease undergoing mitral valve replacement. Preoperative assessment included standard two-dimensional echocardiography to assess LA diameter, volume, and emptying fraction, LV volume and ejection fraction. TDI derived velocity, strain of the left atrium and speckle tracking to assess left ventricular function then postoperative follow up for 1 month for occurrence of atrial fibrillation.

Results

The incidence of postoperative AF was 44%; these patients were significantly older (P = 0.001) and show higher prevalence of DM (P = 0.001) and HTN (P = 0.001). Also, LA diameters (antero-posterior, transverse and longitudinal) and LA volumes (maximal and minimal) were increased (P < 0.001), but no difference in LA emptying fraction (P > 0.05). Systolic LA strain and left ventricular global longitudinal strain were significantly reduced in those patients (P value <0.001). Echocardiographic predictors of AF were LA systolic strain (P value <0.001) and LV global longitudinal strain (P value = 0.003). Cutoff value for systolic LA strain ≤23 had sensitivity 90.91% and specificity 93.33% in predicting POAF. While, left ventricular global longitudinal strain ≤−14.9% had sensitivity 63.6% and specificity 100.0% in predicting AF.

Conclusion

LA systolic strain and LV global longitudinal strain were significant predictors of POAF. Echocardiographic parameters can identify patients at greater risk of developing POAF who can benefit from preventive measure and guide the selection of prosthesis.

The significance of the left atrial volume index in prediction of atrial fibrillation recurrence after electrical cardioversion

Introduction: Electrical cardioversion (ECV) is a safe method for the treatment of atrial fibrillation. It seems that left atrial volume index (LAVI) could be a good marker in predicting the success of ECV. The purpose of this study is to assess of the significance of LAVI measurement before ECV in predicting the recurrence of the AF.

Methods: Fifty-one patients with AF, selected for ECV were studied in the cardiology department of Tabriz University of medical sciences. The clinical and demographic data of all the patients were obtained. Echocardiography was performed before and also three months after ECV. Patients were separated into two groups: those who maintained SR and those with relapse of AF diagnosed by clinical manifestations and electrocardiography (ECG).

Results: Sinus rhythm (SR) was maintained in 76.5 percent of the patients following the three months after ECV. The age, sex and the body mass index (BMI) were not significantly different between SR and AF groups. Two groups showed no significant differences considering pre-ECV medical history including medications and systemic diseases. The initial LAVI of SR group was 42.21±12.4 mL/m² and AF group was 96.08±52.21 mL/m², the initial LAVI was significantly different between two groups (P = 0.000). The LAVI of SR group decreased significantly (5.69±0.74 mL/m²) after three months, LAVI decreased from 42.21 ± 12.4 ml/m² to 37.51 ± 10.52 mL/m². (P = 0.000). The cut-off point of LAVI value in predicting the maintenance of SR was 55 mL/m².

Conclusion: The present study indicates that LAVI is a powerful forecaster of the recurrence of AF after ECV. The LAVI measurement could be a useful method in the selection of the patients with AF for ECV.

Update on hypertrophic cardiomyopathy and a guide to the guidelines

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disorder, affecting 1 in 500 individuals worldwide. Existing epidemiological studies might have underestimated the prevalence of HCM, however, owing to limited inclusion of individuals with early, incomplete phenotypic expression. Clinical manifestations of HCM include diastolic dysfunction, left ventricular outflow tract obstruction, ischaemia, atrial fibrillation, abnormal vascular responses and, in 5% of patients, progression to a 'burnt-out' phase characterized by systolic impairment. Disease-related mortality is most often attributable to sudden cardiac death, heart failure, and embolic stroke. The majority of individuals with HCM, however, have normal or near-normal life expectancy, owing in part to contemporary management strategies including family screening, risk stratification, thromboembolic prophylaxis, and implantation of cardioverter-defibrillators. The clinical guidelines for HCM issued by the ACC Foundation/AHA and the ESC facilitate evaluation and management of the disease. In this Review, we aim to assist clinicians in navigating the guidelines by highlighting important updates, current gaps in knowledge, differences in the recommendations, and challenges in implementing them, including aids and pitfalls in clinical and pathological evaluation. We also discuss the advances in genetics, imaging, and molecular research that will underpin future developments in diagnosis and therapy for HCM.

Quantitative evaluation of left atrial volume and function by one-dimensional, two-dimensional, and three-dimensional echocardiography in a population of normal dogs

OBJECTIVES

The primary goal of this study was to compare left atrial (LA) volume and functional indices in a population of normal dogs using transthoracic one-dimensional M-mode, two-dimensional (2D), and three-dimensional (3D) echocardiography.

ANIMALS

Forty clinically normal dogs of various breeds were stratified into four groups based on weight.

METHODS

Left atrial volume (LAV) was estimated by converting single linear measurements derived from M-mode and 2D images into volumes via the cube and sphere formulas. 2D echocardiography was employed to estimate LAV using linear measures and rectangular and ellipsoid formulas, as well as area-length and the monoplane method of disks. LAV was estimated using the biplane area-length method on 4- and 2-chamber 2D images. LAV was directly measured using 3D volume data obtained over four consecutive cardiac cycles. LAV estimates were compared amongst methods, correlated to body size, and evaluated for reproducibility. Functional indices derived from these various echocardiographic methods were compared to identify any systematic differences based on imaging modality. LA functional indices included LA ejection fraction (LAEF), total LA emptying volume, passive LA emptying volume/fraction, active LA emptying volume/fraction, and LA expansion index.

RESULTS

The M-mode derived estimates of LAV were significantly smaller than all 2D- and 3D-derived LAV (p<0.0001). The left-sided 3D LAV had the highest correlation with body weight (r² = 0.8806) for all phases of the LA cycle with acceptable interobserver variability (CV 11%).

CONCLUSIONS

3D echocardiography is a feasible, non-invasive method to measure LAV in a population of normal dogs.

A simple, fast and reproducible echocardiographic approach to grade left ventricular diastolic function

The American Society of Echocardiography and European Association of Echocardiography (ASE/EAE) have published an algorithm for the grading of diastolic function. However, the ability to use this algorithm effectively in daily clinical practice has not been investigated. We hypothesized that in some patients it may be difficult to grade diastolic dysfunction with this scheme, since there may be discrepancies in the assessed parameters. The aim of the current study was to test the feasibility of the ASE/EAE algorithm and to compare this with a new Thoraxcenter (TXC) algorithm. The ASE/EAE and TXC algorithms were applied to 200 patients. The ASE/EAE algorithm starts with assessment of diastolic myocardial wall velocities and left atrial (LA) volumes with subsequent assessment of E/A ratio, E-wave deceleration time and pulmonary venous flow. The TXC algorithm reverses these steps, uses LA dimension instead of volume and does not include a Valsalva manoeuvre and pulmonary venous flow. Due to inconsistencies between diastolic myocardial wall velocities and LA volumes and a not covered E/A ratio in the range of 1.5–2 it was not possible to classify 48 % of patients with the ASE/EAE algorithm, as opposed to only 10 % by the TXC algorithm. LA volume was always needed in the ASE/EAE algorithm. In only 64 % of patients LA size was necessary by the TXC algorithm. When LA volume would have been used instead of LA dimension, grading of LV diastolic function would have been different in only 2 % of patients without apparent improvement. Assessment of LA dimension was considerably faster than LA volume. The TXC algorithm to grade LV diastolic dysfunction was compared to the ASE/EAE algorithm simpler, faster, better reproducible and yields a higher diagnostic outcome.

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.

Assessment of Left Atrial Function in Patients with Celiac Disease

BACKGROUND

There is some evidence suggesting increased risk of atrial fibrillation (AF) in patients with celiac disease (CD). Impaired left atrial function plays a significant role in the development of AF. This study aimed at assessing the electrical and mechanical functions of the left atrium in patients with CD.

METHODS

A total of 71 patients with biopsy-proven, antibody-positive CD and 52 age-matched healthy controls were included in this prospective study. P-wave dispersion (PWD) was measured to assess the electrical functions of the left atrium through the use of surface electrocardiography. A tissue Doppler echocardiography was performed to determine the atrial conduction and electromechanical delay (EMD) time. To evaluate the mechanical functions of the left atrium, maximum, minimum, and presystolic atrial volumes were estimated to calculate the contractile, conduit, and reservoir functions.

RESULTS

In terms of transthoracic echocardiographic parameters, CD and control subjects were not significantly different. However, as compared to controls, patients with CD had significantly increased PWD (median 52 ms [interquartile range 46-58 ms] vs. 38 [36-40], P < 0.001). Also, significantly higher interatrial (49 ms [32-60] vs. 26 ms [22-28], P < 0.001), intra-left atrial (26 ms [17-44] vs. 14 ms [12-18], P < 0.001), and intra-right atrial (15 ms [8-22] vs. 10 ms [8-14], P < 0.001) EMD was found among CD subjects than controls. Despite an increase in the left atrial volume in patients with CD, conduit and reservoir functions were comparable.

CONCLUSIONS

Although atrial mechanical functions are preserved in patients with CD, a slower electrical conduction was found, suggesting an increased risk of AF in this group of patients.

Which method of left atrium size quantification is the most accurate to recognize thromboembolic risk in patients with non-valvular atrial fibrillation?

BACKGROUND

Left atrial (LA) size is a predictor of cardiovascular outcomes in patients in sinus rhythm, whereas conflicting results have been found in atrial fibrillation (AF). This study aims to: (1) Evaluate the accuracy of LA size to identify surrogate markers of an increased thromboembolic risk in patients with AF; (2) Assess the best method to evaluate LA size in this setting.

METHODS

Cross-sectional study enrolling 500 consecutive patients undergoing transthoracic and transesophageal echocardiography evaluation during a non-valvular AF episode. LA size was measured on transthoracic echocardiography using several methods: anteroposterior diameter, area in four-chamber view, and volumes by the ellipsoid, single- and biplane area-length formulas. Surrogate markers of stroke were evaluated by transesophageal echocardiography: LA appendage (LAA) thrombus, LAA low flow velocities, dense spontaneous echocardiographic contrast and LA abnormality.

RESULTS

Except for non-indexed anteroposterior diameter, increased LA size quantified by all the other methods showed a moderate to high discriminatory power to identify all the surrogate markers of stroke. A higher accuracy was observed for indexed LA area in four-chamber view (LAA thrombus: AUC = 0.708, CI95% 0.644- 0.772, p<0.001; LAA low flow velocities: AUC = 0.733, CI95% 0.674- 0.793, p<0.001; dense spontaneous echocardiographic contrast: AUC = 0.693, CI95% 0.638- 0.748, p<0.001; LA abnormality: AUC = 0.705, CI95% 0.654-0.755, p<0.001), indexed single-plane area-length volume (LAA thrombus: AUC = 0.701, CI95% 0.633-0.770, p<0.001; LAA low flow velocities: AUC = 0.726, CI95% 0.660-0.792, p<0.001; dense spontaneous echocardiographic contrast: AUC = 0.673, CI95% 0.611-0.736, p<0.001; LA abnormality: AUC = 0.687, CI95% 0.629-0.744, p<0.001), and indexed biplane area-length volume (LAA thrombus: AUC = 0.707, CI95% 0.626-0.788, p<0.001; LAA low flow velocities: AUC = 0.737, CI95% 0.664-0.810, p<0.001; dense spontaneous echocardiographic contrast: AUC = 0.651, CI95% 0.578-0.724, p<0.001; LA abnormality: AUC = 0.683, CI95% 0.617-0.749, p<0.001), without significant difference between them. Indexed LA area in four-chamber view and indexed area-length volumes also were independent predictors of surrogate markers of stroke.

CONCLUSIONS

Left atrium enlargement is associated with an increased prevalence of surrogate markers of stroke in patients with non-valvular AF. Indexed LA area in four-chamber view and indexed area-length volumes displayed the strongest association.

Comparison of left atrial function in healthy individuals versus patients with non-ST-segment elevation myocardial infarction using two-dimensional speckle tracking echocardiography

Abstract

Left atrial (LA) function has been associated with adverse outcomes in patients after acute myocardial infarction. The purpose of the current study was to evaluate LA function in patients with non-ST-segment elevation myocardial infarction (NSTEMI) by two-dimensional speckle tracking echocardiography (2D STE). Fifty-one patients with NSTEMI and 40 age-matched normal control individuals were enrolled in this study. Conventional echocardiographic parameters and global longitudinal strain rate (GLSR) were measured at left ventricular (LV) and LA segments. Compared with healthy subjects, patients with NSTEMI had significantly increased LA volumes but significantly decreased LA emptying fraction and GLSR. LA-GLSR had significant correlations with the 2D Doppler echocardiographic parameters of LA function. In particular, global LA peak negative strain rate during early ventricular diastole (LA-GLSRe) was significantly correlated with both LA 2D Doppler echocardiographic parameters and LV contractile function. This could be suggested as a better indicator to evaluate LA function as a preferred parameter of STE.

Left atrial longitudinal strain parameters predict postoperative persistent atrial fibrillation following mitral valve surgery: a speckle tracking echocardiography study

Postoperative atrial fibrillation (POAF) is common after cardiac surgery and is associated with increased morbidity, mortality, and prolonged hospital stay. Speckle tracking echocardiography (STE) has been applied recently for evaluation of LA function. The purpose of this study was to examine whether left atrial longitudinal strain measured by STE is a predictor for the development of POAF following mitral valve surgery for severe mitral regurgitation. We studied 53 patients undergoing mitral valve surgery in sinus rhythm at the time of surgery. Echocardiography with evaluation of LA strain by STE was performed. Detection of POAF was based on documentation of AF episodes by continuous telemetry throughout hospitalization. Patients who did not develop POAF were taken as group 1 and those who had POAF constituted group 2. The echocardiographic and clinical predictors of POAF were investigated. POAF occurred in 28.3% of subjects. Mean age, LAVi and BNP were found higher in group 2 while peak atrial longitudinal strain (PALS) (13.9 ± 3.8% vs. 24.8 ± 7.3%; P < 0.001), peak atrial contraction strain (PACS) (7.6 ± 1.95% vs. 11.3 ± 3.5%; P < 0.001) were significantly lower. By multivariate logistic regression analysis, PALS and LAVi were independent predictor of POAF development. LA longitudinal strain was found to predict POAF in patients undergoing mitral valve surgery. It could be used to better identify patients at greater risk of developing POAF, and thus to guide in risk stratification and to take appropriate intensive prophylactic therapy.

Left atrium reverse remodeling in patients with mitral valve stenosis after percutaneous valvuloplasty: a 2- and 3-dimensional echocardiographic study

INTRODUCTION AND OBJECTIVES

The left atrium is clinically relevant in patients with mitral valve stenosis. The objective of this study was to analyze the effects of percutaneous balloon valvuloplasty on left atrium volumes and the left atrium emptying fraction in symptomatic mitral valve stenosis patients using 2-dimensional and real-time 3 -dimensional transthoracic echocardiography.

METHODS

We carried out a prospective study of 28 consecutive symptomatic mitral valve stenosis patients, aged 22-72 (39 [11.5]) years, 24/28 (85.6%) women, who underwent to percutaneous balloon valvuloplasty between March 2009 and May 2011. Patients underwent 2- and 3-dimensional transthoracic and transesophageal echocardiography (atrial fibrillation) and invasive mitral valve area measurement. Echocardiographic analysis was performed before, 72 h after and 12 months after percutaneous balloon valvuloplasty. The following parameters were analyzed: a) mitral valve area (2-dimensional planimetry, pressure half-time, 3-dimensional echocardiography, invasive hemodynamic measurement); b) indexed left atrium maximum and indexed minimum volumes, and c) left atrium emptying fraction.

RESULTS

The 3-dimensional parameters of the mitral valve stenosis patients before and 72 h and 12 months after percutaneous balloon valvuloplasty were as follows: a) mitral valve area: 0.9 (0.1) cm(2); 1.8 (0.2) cm(2) (P<.001); 1.7 (0.2) cm(2) (P<.001); b) left atrium maximum volumes: 49.9 (12) mL/m(2); 42 (11.4) mL/m(2) (P<.001); 40.3 (10.2) mL/m(2) (P<.001), and c) left atrium emptying fraction: 30.1 (9.4%); 40.6 (7.4%) (P<.001); 44.1 (8%) (P<.001), respectively.

CONCLUSIONS

In symptomatic mitral valve stenosis patients who underwent percutaneous balloon valvuloplasty analysis by 2- and 3-dimensional echocardiography, improvements in left atrium reverse remodeling and left atrium emptying fraction were observed 72 h and 12 months after the procedure.

Novel echocardiographic techniques to assess left atrial size, anatomy and function

Three-dimensional echocardiography (3DE) and speckle tracking echocardiography (STE) have recently applied as imaging techniques to accurately evaluate left atrial (LA) size, anatomy and function. 3DE and off-line quantification softwares, have allowed, in comparison to magnetic resonance imaging, the most time-efficient and accurate method of LA volume quantification. STE provides a non-Doppler, angle-independent and objective quantification of LA myocardial deformation. Data regarding feasibility, accuracy and clinical applications of LA analysis by 3DE and STE are rapidly gathering. This review describes the fundamental concepts of LA 3DE and STE, illustrates how to obtain respective measurements and discuss their recognized and emerging clinical applications.

Quantitative analysis of left atrial function in asymptomatic patients with b-thalassemia major using real-time three-dimensional echocardiography

Background

There is strong evidence that left atrial (LA) size is a prognostic marker in a variety of heart diseases. Recently, real-time three-dimensional echocardiography (RT3DE) has been reported as a useful tool for studying the phasic changes of the left atrial volumes. The aim of this study was to investigate the performance of the left atrium in beta-thalassemic patients with preserved left ventricular ejection fraction (EF) and no iron overload, using RT3DE.

Methods

Twenty-eight asymptomatic b-thalassemic patients (32.2 ± 4.3 years old, 17 men) who were on iron chelating therapy, as well as 20 age- and sex-matched healthy controls underwent transthoracic RT3DE. The patient group had normal echocardiographic systolic and diastolic indices, while there was no myocardial iron disposition according to MRI. Apical full volume data sets were obtained and LA volumes were measured at 3 time points of the cardiac cycle: (1) maximum volume (LAmax) at end-systole, just before mitral valve opening; (2) minimum volume (LAmin) at end-diastole, just before mitral valve closure; and (3) volume before atrial active contraction (LApreA) obtained from the last frame before mitral valve reopening or at time of the P wave on the surface electrocardiogram. From the derived values, left atrial active and passive emptying volumes, as well as the respective emptying fractions were calculated.

Results

Left ventricular EF (59.2 ± 2.5% patients vs. 60.1 ± 2.1% controls), E/A, E/E' were similar between the two groups. Differences in the LAmax, LAmin and LApreA between b-thalassemic patients and controls were non-significant, LAmax:(35.5 ± 13.4 vs 31.8 ± 9.8)cm³, LAmin:(16.0 ± 6.0 vs. 13.5 ±4.2)cm³, and LApreA:(25.4 ± 9.8 vs. 24.3 ± 7.2)cm³. However, left atrial active emptying fraction was reduced in the patient group as compared to the healthy population (34.3 ± 16.4% vs. 43.2 ± 11.4%, p < 0.05).

Conclusion

RT3DE may be a novel technique for the evaluation of LA function in asymptomatic patients with b-Thalassemia Major. Among three-dimensional volumes and indices, left atrial active emptying fraction may be an early index of LA dysfunction in the specific patient population.

Comparison between direct volumetric and speckle tracking methodologies for left ventricular and left atrial chamber quantification by three-dimensional echocardiography

In an era of rapidly expanding and evolving 3-dimensional echocardiographic (3DE) technology, 1 of the issues facing the 3DE quantification of chamber volumes and function is that different software vendors use different methodologies and algorithms. The aim of this study was to evaluate the comparability and reproducibility of 3DE direct volumetric and speckle-tracking methods for left ventricular (LV) and left atrial (LA) chamber quantification. A total of 120 subjects (mean age 53 ± 17 years, 65% men), including 88 unselected patients and 32 healthy volunteers, underwent 3DE acquisitions and analysis using direct volumetric and speckle-tracking methods successively. Measurements of LV and LA volumes and LV function were compared between the 2 3DE methods. Additionally, intraobserver and interobserver reproducibility was assessed in 40 randomly selected patients. Measurements of LV end-diastolic volume, end-systolic volume, and ejection fraction by 3DE direct volumetric and 3DE speckle-tracking methods were comparable, with good correlations (r = 0.98, r = 0.98, and r = 0.87, respectively), small biases, and narrow limits of agreement (-1 ± 8 ml, -1 ± 8 ml, and 0 ± 6%, respectively). For measurements of LA end-systolic volume and end-diastolic volume, similar correlations (r = 0.96 for both), small biases, and narrow limits of agreement (-2 ± 6 and -1 ± 5 ml, respectively) were found between the 2 methods. Intraobserver and interobserver reproducibility for LV and LA quantification were comparable for the 2 methods. In conclusion, 3DE direct volumetric and speckle-tracking methods give comparable and reproducible quantification of LV and LA volumes and function, making interchangeable application a viable option in daily clinical practice.

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

AIMS

A novel real-time three-dimensional echocardiography (RT3DE) analysis tool specifically designed for evaluation of the left atrium enables comprehensive evaluation of left atrial (LA) size, global, and regional function using a dynamic 16-segment model. The aim of this study was the initial validation of this method using computed tomography (CT) as the method of reference.

METHODS AND RESULTS

The study population consisted of 34 prospectively enrolled patients with clinical indication for pulmonary vein isolation. A dynamic polyhedron model of the left atrium was generated using RT3DE. LA maximum and minimum volumes (LA(max)/LA(min)) and emptying fraction (LAEF) were determined and compared with the results obtained by CT. High correlations between RT3DE and CT were found for LA(max) (r = 0.92, P < 0.001), LA(min) (r = 0.95, P < 0.001), and LAEF (r = 0.82, P < 0.001). LA(max) and LA(min) were lower by RT3DE than by CT (95.0 ± 44.7 vs. 119.8 ± 50.5 mL, P < 0.001 and 58.1 ± 41.3 vs. 83.3 ± 52.6 mL, P < 0.001, respectively), whereas LAEF was measured higher by RT3DE (42.8 ± 15.2 vs. 34.2 ± 15.4%, P < 0.001, respectively). RT3DE measurements closely correlated in terms of intra-observer (intra-class correlation r = 0.99, r = 0.99, r = 0.96, respectively) and inter-observer variability (r = 0.97, r = 0.98, r = 0.88, respectively).

CONCLUSIONS

LA volumes and EF as assessed by RT3DE correlate highly with CT measurements, albeit there is some bias between the imaging modalities. Most importantly, RT3DE measurements using the novel dedicated LA analysis tool are robust in terms of observer variability and thus suitable for follow-up analyses.