Approaching regional left atrial function by tissue Doppler velocity and strain imaging

Atrial Strain and Strain Rate in a General Population: Do These Measures Improve the Assessment of Elevated NT-proBNP Levels?

Background

Noninvasive assessment of elevated filling pressure in the left ventricle (LV) remains an unresolved problem. Of the many echocardiographic parameters used to evaluate diastolic pressure, the left atrial strain and strain rate (LA S/SR) have shown promise in clinical settings. However, only a few previous studies have evaluated LA S/SR in larger populations.

Methods

A total of 2033 participants from Norwegian (Tromsø 7) and Russian (Know Your Heart) population studies, equally distributed by age and sex, underwent echocardiography, including atrial and ventricular S/SR and NT-proBNP measurements. Of these, 1069 were identified as healthy (without hypertension (HT), atrial fibrillation (AF), or structural cardiac disease) and were used to define the age- and sex-adjusted normal ranges of LA S/SR. Furthermore, the total study population was divided into groups according to ejection fraction (EF) ≥50%, EF <50%, and AF. In each group, uni- and multiple regression and receiver operating characteristic curve analyses were performed to test LA and LV functional parameters as potential indicators of NT-proBNP levels above 250 ng/ml.

Results

The mean LA S/SR values in this study were higher than those in previous large studies, whereas the lower references were comparable. In normal hearts, atrial total strain (ATS) and mitral valve E deceleration time (MV DT) were independent factors indicating elevated NT-proBNP levels, whereas in hearts with reduced EFs, the independent indicators were peak atrial contraction strain (PACS) and LV stroke volume. The areas under the curve for these significant indicators to discriminate elevated NT-proBNP levels were 0.639 (95% confidence interval (CI): 0.577-0.701) for normal EF and 0.805 (CI: 0.675-0.935) for reduced EF.

Conclusion

The results confirm good intrastudy reproducibility, with mean values in the upper range of previous meta-analyses. In the future, automated border-detection algorithms may be able to generate highly reproducible normal values. Furthermore, the study showed atrial S/SR as an additional indicator of elevated NT-proBNP levels in the general population, demonstrating the incremental value of both ATS and PACS in addition to conventional and ventricular strain echocardiography. Thus, the LA S/SR may be regarded as an important addition to the multiparametric approach used for evaluating LV filling.

Pathophysiology and clinical relevance of atrial myopathy

Atrial myopathy is a condition that consists of electrical, structural, contractile, and autonomic remodeling of the atria and is the substrate for development of atrial fibrillation, the most common arrhythmia. Pathophysiologic mechanisms driving atrial myopathy are inflammation, oxidative stress, atrial stretch, and neurohormonal signals, e.g., angiotensin-II and aldosterone. These mechanisms initiate the structural and functional remodeling of the atrial myocardium. Novel therapeutic strategies are being developed that target the pathophysiologic mechanisms of atrial myopathy. In this review, we will discuss the pathophysiology of atrial myopathy, as well as diagnostic and therapeutic strategies.

Prognostic relevance of left atrial function and stiffness in heart failure with preserved ejection fraction patients with and without diabetes mellitus

Background

Although the left atrium (LA) plays a key role in the pathophysiology and disease progression of heart failure with preserved ejection fraction (HFpEF), the impact of type 2 diabetes mellitus (T2DM) on LA function and stiffness in HFpEF patients remains unclear. Furthermore, the prognostic value of different phases of LA function and stiffness is less well-established in HFpEF patients.

Methods

This study prospectively enrolled 164 HFpEF patients who were in sinus rhythm at the time of echocardiography, including 61 (37%) HFpEF patients with T2DM. LA reservoir, conduit, and pump function were assessed using two-dimensional volume indices and speckle tracking echocardiography. The LA stiffness was calculated as the ratio of early mitral inflow velocity-to-early annular tissue velocity (E/e’) and LA reservoir function. The primary end point was a combined outcome of heart failure hospitalization or death.

Results

Left atrium reservoir function [measured by peak LA strain (LAS-peak)] and LA pump function (measured by LAS-active) remained significantly lower in the HFpEF patients with T2DM compared with those without T2DM, even after adjustment for potential confounders. In addition, the LA stiffness of HFpEF patients with T2DM was higher than those without T2DM. After a median follow-up of 13.7 months, 46 patients (28.1%) reached the composite end point. LAS-peak (hazard ratios: 0.88; 95% confidence interval: 0.81–0.95; P = 0.001) was significantly associated with the risk of heart failure hospitalization or death after adjusting for demographic and clinical characteristics, LV global longitudinal strain, E/e’, and LA volume index. In contrast, other LA function and stiffness parameters did not independently predict the risk of adverse events. Kaplan-Meier analysis showed that HFpEF patients with T2DM and low LAS-peak (<27.2%) had a significantly increased risk of heart failure-related hospitalization or death (log-rank P < 0.001).

Conclusion

Left atrium reservoir and pump function are impaired, whereas LA stiffness is increased in HFpEF patients with T2DM compared with those without T2DM. LAS-peak is a powerful predictor of adverse clinical outcomes and may be crucial for risk stratification in HFpEF patients with and without T2DM.

Assessment of Left Atrial Structure and Function by Echocardiography in Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia with significant morbidity and mortality. Exacerbated by the aging population, the prevalence of AF is gradually increasing. Accurate evaluation of structure and function of left atrium (LA) has important prognostic significance in patients with AF. Echocardiography is the imaging technique of first choice to assess LA structure and function due to its better availability, accessibility and safety over cardiac computed tomography and cardiac magnetic resonance. Therefore, the aim of this review is to summarize the recent research progress of evaluating LA size by three-dimensional echocardiography and LA function by speckle tracking echocardiography (STE) in predicting the occurrence and recurrence of AF and determining the risk of stroke in AF. In addition, we summarized the role of traditional echocardiography in detecting AF patients that are at high risk of heart failure or cardiovascular death.

Magnetic-Resonance-Imaging-Based Left Atrial Strain and Left Atrial Strain Rate as Diagnostic Parameters in Cardiac Amyloidosis

Aims: The present study aims to evaluate magnetic-resonance-imaging (MRI)-assessed left atrial strain (LAS) and left atrial strain rate (LASR) as potential parameters for the diagnosis of cardiac amyloidosis (CA), the distinction of clinical subtypes and differentiation from other cardiomyopathies. Methods and results: LAS and LASR were assessed by MRI feature tracking in patients with biopsy-proven CA. LAS and LASR of patients with CA were compared to healthy subjects and patients with hypertrophic cardiomyopathy. LAS and LASR were also analyzed concerning differences between patients with transthyretin (ATTR) and light chain amyloidosis (AL). A total of 44 patients with biopsy-proven CA, 19 patients with hypertrophic cardiomyopathy and 24 healthy subjects were included. In 22 CA patients (50%), histological examination identified ATTR as CA subtype and AL in the remaining patients. No significant difference was observed for reservoir, conduit or booster LAS in patients with AL or ATTR. Reservoir LAS, conduit LAS and booster LAS were significantly reduced in patients with CA and HCM as compared to healthy subjects (p < 0.001). Reservoir LAS and booster LAS were significantly reduced in CA as compared to HCM patients (p < 0.001). A linear correlation was observed between LA global reservoir strain and LA-EF (p < 0.001, r = 0.5), conduit strain and global longitudinal LV strain (p < 0.001, r = 0.5), global booster strain rate and LA-EF (p < 0.001, r = 0.6) and between global booster strain rate and LA area at LVED (p < 0.0001, 0.5). Conclusions: LAS and LASR are severely impaired in patients with CA. The MRI-based assessment of LAS and LASR might allow non-invasive diagnosis and categorization of CA and its distinct differentiation from other hypertrophic phenotypes.

Multimodality Imaging in the Study of the Left Atrium

The left atrium (LA) plays a vital role in maintaining normal cardiac function. Many cardiac diseases involve the functioning of the LA directly or indirectly. For this reason, the study of the LA has become a priority for today's imaging techniques. Assessment of LA size, function and wall characteristics is routinely performed in cardiac imaging laboratories when a patient undergoes transthoracic echocardiography. However, in cases when the LA is the focus of disease management, such as in atrial fibrillation or left atrial appendage closure, the use of multimodality is critical. Knowledge of the usefulness of each cardiac imaging technique for the study of LA in these patients is crucial in order to choose the most appropriate treatment. While echocardiography is the most widely performed technique for its evaluation and the study of wall deformation analysis is increasingly becoming more reliable, multidetector computed tomography allows a detailed analysis of its anatomy to be carried out in 3D reconstructions that help in the approach to interventional treatments. In addition, the evaluation of the wall by cardiac magnetic resonance imaging or the generation of electroanatomical maps in the electrophysiology room have become essential tools in the treatment of multiple atrial pathologies. For this reason, the goal of this review article is to describe the basic anatomical and functional information of the LA as well as their study employing the main imaging techniques currently available, so that practitioners specializing in cardiac imaging techniques can use these tools in an accurate and clinically useful manner.

Left atrial morpho-functional remodeling in atrial fibrillation assessed by three dimensional speckle tracking echocardiography and its value in atrial fibrillation screening

BACKGROUND

Three dimensional speckle tracking echocardiography (3D STE) is a novel technique combining 3D echocardiography and speckle tracking analysis. 3D STE software dedicated to the left atrium (LA) was recently available. Our study aimed to assess (1) atrial fibrillation (AF) related LA morpho-functional remodeling using 3D STE and (2) value of LA function parameters in identifying paroxysmal AF (PAF).

METHODS

One hundred thirty-nine PAF, 109 persistent AF (Per-AF) and 59 non-AF subjects underwent 3D STE. LA phasic volumes and total LA emptying fraction (LAEF) were obtained and used to calculate passive (pLAEF) and active LA emptying fraction (aLAEF) based on atrial contraction. LA longitudinal and circumferential strain representing reservoir (LASr/LASrc), conduit (LAScd/LAScdc) and pump (LASct/LASctc) function were also assessed.

RESULTS

3D STE was found to have good reproducibility. Increase of LA volumes and decrease of parameters representing LA reservoir and pump function were independently associated with AF as well as AF burden. The correlations between LA emptying fraction and LA circumferential strain representing the same function were always stronger than those with LA longitudinal strain (p < 0.001). Minimal LA volume, LAEF, aLAEF, LASrc and LASctc can be used to accurately differentiate PAF from non-AF subjects (AUC > 0.8) with great sensitivity and specificity.

CONCLUSIONS

Assessing LA remodeling in AF using 3D STE was feasible. AF and AF burden were independently associated with LA enlargement and impairment of reservoir and pump function but not conduit function. LA function parameters can indicate underlying PAF and thus can guide AF screening strategy.

Echocardiographic and Electrocardiographic Determinants of Atrial Cardiomyopathy Identify Patients with Atrial Fibrillation at Risk for Left Atrial Thrombogenesis

Objective: Atrial cardiomyopathy (ACM) is associated with development of AF, left atrial (LA) thrombogenesis, and stroke. Diagnosis of ACM is feasible using both echocardiographic LA strain imaging and measurement of the amplified p-wave duration (APWD) in digital 12-lead-ECG. We sought to determine the thresholds of LA global longitudinal strain (LA-GLS) and APWD that identify patients with AF at risk for LA appendage (LAA) thrombogenesis. Methods: One hundred and twenty-eight patients with a history of AF were included. Left atrial appendage maximal flow velocity (LAA-Vel, in TEE), LA-GLS (TTE), and APWD (digital 12-lead-ECG) were measured in all patients. ROC analysis was performed for each method to determine the thresholds for LA-GLS and the APWD, enabling diagnosis of patients with LAA-thrombus. Results: Significant differences in LA-GLS were found during both rhythms (SR and AF) between the thrombus group and control group: LA-GLS in SR: 14.3 ± 7.4% vs. 24.6 ± 9.0%, p < 0.001 and in AF: 11.4 ± 4.2% vs. 16.1 ± 5.0%, p = 0.045. ROC analysis revealed a threshold of 17.45% for the entire cohort (AUC 0.82, sensitivity: 84.6%, specificity: 63.6%, Negative Predictive Value (NPV): 94.3%) with additional rhythm-specific thresholds: 19.1% in SR and 13.9% in AF, and a threshold of 165 ms for APWD (AUC 0.90, sensitivity: 88.5%, specificity: 75.5%, NPV: 96.2%) as optimal discriminators of LAA-thrombus. Moreover, both LA-GLS and APWD correlated well with the established contractile LA-parameter LAA-Vel in TEE (r = 0.39, p < 0.001 and r = −0.39, p < 0.001, respectively). Conclusion: LA-GLS and APWD are valuable diagnostic predictors of left atrial thrombogenesis in patients with AF.

Prognostic value of left atrial strain in patients with wild-type transthyretin amyloid cardiomyopathy

Aims

This study was performed to investigate whether left atrial (LA) strain by echocardiography provides prognostic information in patients with wild‐type transthyretin amyloid cardiomyopathy (ATTRwt‐CM).

Methods and results

Among 129 patients who were diagnosed with ATTRwt‐CM at Kumamoto University Hospital from December 2002 to December 2019, 113 patients who had enough information for two‐dimensional speckle tracking echocardiography were enrolled in this study. During a median follow‐up of 668 days, 28 cardiovascular deaths occurred. Compared with patients in the non‐event group, those in the cardiovascular death group were significantly older (81.5 ± 7.4 vs. 78.1 ± 6.1 years, P < 0.01), had a lower incidence of carpal tunnel syndrome (21% vs. 47%, P < 0.05), and had a higher high‐sensitivity cardiac troponin T [0.085 (0.063–0.105) vs. 0.049 (0.036–0.079) ng/mL, P < 0.01] and B‐type natriuretic peptide concentrations [419 (239–541) vs. 271 (155–462) pg/mL, P < 0.01] and lower estimated glomerular filtration rate (41.8 ± 15.4 vs. 53.4 ± 14.6 mL/min/1.73 m², P < 0.01). Electrocardiography showed higher rate of a V1–V3 QS pattern (52% vs. 24%, P < 0.01) and complete left bundle branch block (27% vs. 6%, P < 0.01), and echocardiography showed a significantly lower peak LA strain rate during the contraction phase (0.16 ± 0.13 vs. 0.28 ± 0.27 S⁻¹, P < 0.05), LA strain during the reservoir phase (LASr) (5.84 ± 2.41 vs. 8.22 ± 4.05%, P < 0.01), and peak LA strain rate during the reservoir phase (0.26 ± 0.09 vs. 0.33 ± 0.15 S⁻¹, P < 0.05) in the cardiovascular death group than in non‐event group. By contrast, conventional echocardiographic findings were not significantly different between these two groups. After adjusting for conventional predictive factors of ATTRwt‐CM (age, high‐sensitivity cardiac troponin T and B‐type natriuretic peptide concentrations, and estimated glomerular filtration rate), multivariable Cox proportional hazard analyses showed that LASr was significantly and independently associated with cardiovascular death in patients with ATTRwt‐CM (odds ratio, 0.84; 95% confidence interval, 0.72–0.98; P < 0.05). After adjusting for age and echocardiographic findings associated with cardiovascular death (LA volume index and peak LA strain rate during the contraction phase), LASr was significantly and independently associated with cardiovascular death in patients with ATTRwt‐CM (odds ratio, 0.83; 95% confidence interval, 0.70–0.98; P < 0.05). Receiver operating characteristic curve analysis showed that the area under the curve of LASr for cardiovascular death was 0.686 and that the best cut‐off value of LASr was 6.69% (sensitivity, 62.4%; specificity, 64.3%). In the Kaplan–Meier analysis, patients with low LASr (<6.69%) had a significantly higher probability of total cardiovascular death (P < 0.05) and heart failure‐related hospitalization (P < 0.05).

Conclusions

Left atrial strain during the reservoir phase provides significant prognostic value in patients with ATTRwt‐CM even after adjusting for conventional predictive factors.

Determinants of exercise intolerance symptoms considered non-specific for heart failure in patients with stage A and B: role of the left atrium in the transition phase to overt heart failure

To assess to what extent left atrial (LA) structure and function are associated with non-specific heart failure symptoms, so that patients were classified as HF stage A and B. Mechanisms underlying the transition to overt HF in patients with stage A and B HF are unclear. Consecutive outpatients undergoing echocardiography and clinical evaluation and classified as HF stage A and B with preserved left ventricular ejection fraction (LVEF) were included. The association between LA measures [volume (LAVi), peak longitudinal-(PALS), contraction-(PACS) and conduit-strain] and non-specific HF symptoms was assessed using adjusted logistic regression analyses. The incremental value of atrial myopathy in symptoms prediction on top of clinical or echocardiographic confounders was assessed through ROC curves analyses. The cohort comprehended 185 patients (63 ± 16 years, 47% women) of whom 133 (72%) were asymptomatic, and 52 (28%) reported non-specific HF symptoms. After adjustment for clinical and echocardiographic confounders for HF symptoms, LAVi, PALS and PACS were associated with symptoms (p < 0.05). Among echocardiographic variables, only LA parameters were significantly associated with symptoms on top of clinical confounders (for LAVi OR [95% CI] 1.56 [1.21–2.00], p < 0.0001; for PALS 1.45 (1.10–1.91), p = 0.0009; for PACS 2.10 [1.33–3.30], p = 0.002). After adjustment for age, hypertension and COPD or E/E′, LV mass-i and mitral ERO, atrial myopathy added predictive value for symptoms presence compared to the clinical variables or echocardiographic parameters described (AUC increase 0.80 to 0.88, p = 0.004, and 0.79 to 0.84, p = 0.06, respectively). In patients with HF stages A–B and preserved LVEF, measures of LA structure and function were associated with non-specific HF symptoms. A comprehensive LA remodeling evaluation may help clinicians in the appropriate identification of overt HF.

Detection of congestive heart failure by mitral annular displacement in cats with hypertrophic cardiomyopathy - concordance between tissue Doppler imaging-derived tissue tracking and M-mode

INTRODUCTION

The left ventricular systolic longitudinal function, traditionally measured by M-mode-derived mitral annular plane systolic excursion (MAPSE), is reduced in feline hypertrophic cardiomyopathy (HCM) and further reduced in cats with left-sided congestive heart failure (CHF). The objectives of this study were to compare longitudinal displacement measured by tissue tracking (TT-LD) and MAPSE in feline HCM and assess these methods' ability to differentiate CHF from preclinical HCM. A further objective was to provide preliminary reference intervals for TT-LD.

ANIMALS

Eighty-five client-owned cats.

METHODS

A retrospective case-control study. Anatomical M-mode was used to record MAPSE, and TT-LD was recorded by tissue tracking.

RESULTS

Reduced longitudinal displacement measured by either MAPSE or TT-LD was significantly associated with CHF in cats with HCM (p < 0.036). Receiver-operating characteristic analysis indicated that TT-LD (AUC: 92.9%-97.9%) was more sensitive and specific than MAPSE (AUC: 85.8%-89.1%) for the detection of CHF. A diagnostic cut-off of 2.89 mm for maximal TT-LD in the left ventricular septum resulted in a sensitivity and specificity of 100% and 83.3%, while a diagnostic cut-off of 2.41 mm in the left ventricular posterior wall resulted in a sensitivity of 100% and a specificity of 90%.

CONCLUSIONS

M-mode-derived mitral annular plane systolic excursion and TT-LD were strongly correlated, but not interchangeable. Longitudinal displacement measured by tissue tracking decreased more with disease severity than traditional MAPSE. Longitudinal displacement may help detect CHF in cats with HCM - with the maximal TT-LD of the left ventricular posterior wall achieving the highest AUC value.

Left Atrial Myopathy in Atrial Fibrillation and Heart Failure: Clinical Implications, Mechanisms, and Therapeutic Targets

PURPOSE OF REVIEW

This review discusses the mechanisms, clinical implications, and treatments of left atrial (LA) myopathy in comorbid atrial fibrillation (AF) and heart failure (HF) across the spectrum of ejection fraction.

RECENT FINDINGS

AF and HF are highly comorbid conditions. Left atrial (LA) myopathy, characterized by impairments in LA structure, function, or electrical conduction, plays a fundamental role in the development of both AF and HF with preserved ejection fraction (AF-HFpEF) along with AF and HF with reduced ejection fraction (AF-HFrEF). While the nature of LA myopathy in AF-HFpEF is unique from that of AF-HFrEF, LA myopathy also leads to progression of both of these conditions. There may be a vulnerable cohort of AF-HF patients who have a disproportionate degree of LA myopathy compared with left ventricular (LV) dysfunction. Further investigations are required to identify therapies to improve LA function in this cohort.

The decrease in peak atrial longitudinal strain in patients with atrial fibrillation as a practical parameter for stroke risk stratification

BACKGROUND

Decreased peak atrial longitudinal strain (LA strain) derived from 2-dimensional speckle tracking is frequently observed in patients with atrial fibrillation (AF) and associated with the risk of ischemic stroke.

OBJECTIVES

We aimed to study the predictive power of the decrease in LA strain in population with AF and hypothesize that the difference in LA strain between reference values could be used in a stratified way for prognostication.

METHODS

Echocardiography examination was performed using the GE system [GE Vivid i system (GE Healthcare, Horten, Norway)]. The standard score of LA strain (ZLA) was calculated, and patients were classified into 5 groups: Z0 (0 to -1), Z-1 (-1 to -2), Z-2 (-2 to -3), Z-3, (-3 to -4), and Z-4 (≤-4). The clinical end point was an ischemic stroke.

RESULTS

Of the 1364 subjects with AF (mean age 71.4 ± 12.1 years; 759 men (55.6%), 105 encountered ischemic strokes during a mean follow-up period of 3.1 ± 1.6 years. No patients in the Z0 and Z-1 groups encountered ischemic stroke. The Kaplan-Meier analysis showed higher rates of stroke in worse ZLA groups. Compared with the Z-2 group, a significantly increased risk of stroke was found in the Z-3 (hazard ratio 3.697; 95% confidence interval 1.966-6.951; P < .001) and Z-4 (hazard ratio 6.447; 95% confidence interval 2.990-13.904; P < .001) groups in univariate Cox regression analysis. The results remained consistent after multivariate Cox regression analysis.

CONCLUSION

The decrease in LA strain could be applied in a stratified manner and is significantly associated with the risk of stroke independent of the baseline covariates.

Global Left Atrial Longitudinal Strain Using 3-Beat Method Improves Risk Prediction of Stroke Over Conventional Echocardiography in Atrial Fibrillation

Background:

Atrial fibrillation (AF) is associated with a risk of ischemic stroke, and functional myocardial imaging has offered novel insights on its pathophysiology and prognosis, but its use in AF-related stroke remains limited. We aimed to evaluate the feasibility of left atrial (LA) deformations and its prognostic values of ischemic stroke in a large-scale AF population.

Methods:

Peak atrial longitudinal strain (LA strain), left ventricular strain (global longitudinal strain), LA strain rate (LA SR) at reservoir (LA longitudinal systolic strain rate), and early diastolic conduit (LA longitudinal early diastolic strain rate) phases were analyzed using 2-dimensional speckle tracking echocardiography. Consecutive 3-beat averaged values of strain and SR were used. The clinical end point was ischemic stroke.

Results:

Among 1457 AF participants, the mean LA strain, LA longitudinal systolic strain rate, and LA longitudinal early diastolic strain rate values were 12.9±4.8%, 0.80±0.28 s − 1 , and −1.17±0.46 s − 1 , respectively. There were strong positive linear relationships of 3-beat average with index-beat analysis (R=0.94, 0.94, and 0.94 for LA strain, LA longitudinal systolic strain rate, and LA longitudinal early diastolic strain rate, respectively; all P <0.001). Multivariate Cox regression models incorporating conventional echocardiography parameters demonstrated LA strain and SRs to be independent prognosticators of ischemic stroke during a median follow-up of 37.6 months. Utilization of LA strain further provided incremental value over CHA 2 DS 2 -VASc scoring ( C statistics, 0.78–0.81; P =0.006) for ischemic stroke. Overall, the prognostic performances of LA deformations were attenuated after adding global longitudinal strains in models.

Conclusions:

LA deformations by the 3-beat method are feasible and reproducible during AF. LA strain provided additional prognostic implication over clinical information and conventional echocardiographic measures for ischemic stroke in the AF population but not incremental to global longitudinal strains.

Correlation of left atrial strain with left ventricular end-diastolic pressure in patients with normal left ventricular ejection fraction

Left ventricular diastolic dysfunction (LVDD) remains challenging to be assessed by echocardiography. We sought to explore the relationship between left atrial strain and left ventricular (LV) diastolic function in patients with normal left ventricular ejection fraction (LVEF) by invasive left-heart catheterization. 55 consecutive individuals with LVEF > 50% underwent LV catheterization. Standard transthoracic echocardiography was performed during 12 h before or after the procedure. Left atrial (LA) strain were obtained by speckle tracking echocardiography. When LVEF ≥ 50%, the group with elevated left ventricular end-diastolic pressure (LVEDP) (n = 35) showed decreased left atrial reservoir strain (LASr) (35.2 ± 7.7% vs 21.3 ± 7.2%, p < 0.001), left atrial conduit strain (LASct) (17.6 ± 6.3% vs 11.9 ± 4.1%, p < 0.001), left atrial contraction strain (LAScd) (16.6 ± 7.2% vs 9.5 ± 5.0%, p < 0.001) and increased E/e′ ration(8.9 ± 2.6 vs 10.1 ± 3.5, p = 0.17). LVEDP negatively correlated with LASr (R = 0.662, p < 0.001), LASct (R = 0.575, p < 0.001) and LAScd (R = 0.456, p < 0.001), but not with E/e′. LASr, LASct and LAScd were all independent predictors of elevated LVEDP (p < 0.05), with a higher C-statistic for the model including LASr (0.95, 0.86 and 0.93 respectively). The area under the curve (AUC) for LASr is 0.914 (cutoff value is 26.7%, sensitivity is 90%, specificity is 82.9%). In patients with normal LV ejection fraction, left atrial strain presented good correlation with LVEDP, and LASr was superior to LASct and LAScd to predict LVEDP. LA strain demonstrated better agreement with the invasive reference than E/e′.

The role of the left atrial function in the surgical management of aortic and mitral valve disease

The right management of both mitral and aortic disease can be challenging, especially in asymptomatic patients. The current guidelines recommend valve repair or replacement when symptoms arise or when there is an evident left ventricular dysfunction. However, deciding the optimal surgical timing can be very difficult, since the line between the absence of symptoms and being minimally symptomatic, especially in the elderly, is blurred. Another relevant issue regards the second surgical criterion: operating on a patient with a reduced left ventricular ejection fraction or with a dilated left ventricle might jeopardize the possibility of a fully reverse remodeling of the heart after surgery. In this scenario, the left atrium might play an important role. In particular, left atrial deformation might be a very useful tool to detect early ultrastructural alterations, and help or support guiding a patient-tailored treatment at an early stage, optimizing the outcome in the long term.

Assessment of left and right atrial geometrical changes in patients with stable coronary artery disease: Left and right atrial strain and strain rate imaging study

Objective

In patients with coronary artery disease (CAD), there are several studies that assessed the left ventricular (LV) function by strain (S) and strain rate (SR) imaging. The aim of this study is to evaluate the function of both atria in patients with CAD using strain and strain rate imaging, and to correlate this with the severity of CAD.

Methods

We conducted a prospective, single center case control study for 40 consecutive patients who presented to our department with chronic stable angina and were candidates for invasive coronary angiography. We enrolled patients from December 2013 to May 2014 and each patient was subjected to echocardiographic assessment of E/e' of mitral valve, left atrial volume index (LAVI), right atrial volume index (RAVI), and peak atrial longitudinal strain (es) and strain rate (SR) during LV systole. This was followed by invasive coronary angiography for assessment of the severity of CAD using Gensini score. Patients were classified according to angiographic results into 3 groups: Group I (Gensini score = zero), Group II (Gensini score > 0 and < 20) and Group III (Gensini score ≥ 20).

Results

There was no statistically significant difference between the three groups in either LA volumes (V_min, V_max) and distensibility with p value of 0.272, 0.126, and 0.243 respectively or RA volumes and distensibility with a p value of 0.671, 0.183, and 0.259 respectively. On the other hand, LA & RA systolic S and SR were significantly lower among CAD patients in comparison with the group of normal coronaries. Mean LA S and SR was decreased in group III than group II (15.97 ± 3.73, 21.8 ± 6.75 % and 1.11 ± 0.30, 1.81 ± 1.23 s^-1) with p value of 0.005&0.041 respectively. RA systolic S and SR were significantly lower in the 2 groups with CAD than the group with normal coronaries with a p value of 0.001 and 0.002 respectively.

Conclusion

In patients with CAD and normal EF, borderline E/e' ratio and normal atrial size, there are decreased LA and RA systolic S and SR parameters with no effect on atrial volumes or distensibility. Accordingly, this could prove that atrial wall deformation occurs early in CAD even before any changes in atrial volumes or dimensions.

Left atrium: the last bulwark before overt heart failure

Heart failure (HF) with preserved ejection fraction (HFpEF) has emerged as an important public health issue in recent years. It represents the most common type of HF in ambulatory setting, and it has been recognized as a different entity from the reduced ejection fraction (EF) form. In HFpEF, continuous growing attention has been focused on the role of the left atrium (LA) in preserving good ventricular function and asymptomatic condition of the patient since the very first stages of diastolic dysfunction (DD). Non-invasive and complete echocardiographic evaluation of diastolic phase cannot exempt from accurately analyzed LA size, mostly LA volume, and its function, in particular LA myocardial deformation by speckle tracking echocardiography (STE). This review examines the expanding role of the LA in DD and HFpEF and the importance of its complete assessment in various settings, from diagnosis to correlation with major cardiovascular events.

Modern Imaging Techniques in Cardiomyopathies

Modern advanced imaging techniques have allowed increasingly more rigorous assessment of the cardiac structure and function of several types of cardiomyopathies. In contemporary cardiology practice, echocardiography and cardiac magnetic resonance imaging are widely used to provide a basic framework in the evaluation and management of cardiomyopathies. Echocardiography is the quintessential imaging technique owing to its unique ability to provide real-time images of the beating heart with good temporal resolution, combined with its noninvasive nature, cost-effectiveness, availability, and portability. Cardiac magnetic resonance imaging provides data that are both complementary and uniquely distinct, thus allowing for insights into the disease process that until recently were not possible. The new catchphrase in the evaluation of cardiomyopathies is multimodality imaging, which is purported to be the efficient integration of various methods of cardiovascular imaging to improve the ability to diagnose, guide therapy, or predict outcomes. It usually involves an integrated approach to the use of echocardiography and cardiac magnetic resonance imaging for the assessment of cardiomyopathies, and, on occasion, single-photon emission computed tomography and such specialized techniques as pyrophosphate scanning.

Decreased left atrial myocardial strain in patients with suboptimal blood pressure control

BACKGROUND

Suboptimal blood pressure (BP) control is commonly observed in patients receiving antihypertensive agents, but the relationship between uncontrolled BP and left atrial (LA) impairment remains unknown.

METHODS

This study enrolled 279 hypertensive patients who had been medicated, as well as 85 matched normal controls. The BP of systolic <140 mmHg and diastolic<90 mmHg was defined as optimal (HT1 group, n=146), otherwise as suboptimal BP control (HT2 group, n = 133). LA myocardial function was assessed by the systolic (S_Sa), early diastolic (S_Ea), and late diastolic (S_Aa) LA strains.

RESULTS

Both the HT1 group and HT2 group had higher BP reading, thicker interventricular septum, larger LA volume index, and enhanced active atrial emptying fraction than the control group (all <0.05). When compared with normal subjects, hypertensive patients displayed obvious reduction in the S_Sa (50.0 ± 10.9 vs. 35.9 ± 8.0%), S_Ea (30.1 ± 7.7 vs. 18.5 ± 7.1%) and S_Aa (19.9 ± 6.4 vs. 17.8 ± 4.2%) (all p < 0.001). In addition to a further impaired S_Ea found in the HT2 group than in the HT1 group (17.2 ± 5.3 vs. 19.8 ± 8.3%, p = 0.002), the treated BP of >140/90 mmHg appeared an independent risk factor associated with the abnormal S_Ea (odds ratio, 2.957; interval of confidence, 1.614-5.415; p = 0.001).

CONCLUSIONS

Suboptimal BP control status in hypertensive patients is related to a further reduction of LA myocardial function assessed by the novel 2DSTI free strain, and suboptimal BP might be regarded as a composite risk factor and therefore a simplified treatment target. However, the prognostic value of LA free strain in patients with inability to achieve the BP target needs to be evaluated in future prospective studies.

Left atrial appendage function assessment and thrombus identification

Background

The diagnosis of thrombus in the left atrium in patients with persistent atrial fibrillation (AF) and may be inconsistent because of variability in thrombus morphology. In some cases it is challenging and requires unusual approach. New Doppler-derived methods might be helpful to identify such thrombi. We evaluated quantitative differences in mechanical function of the left atrial appendage (LAA) basal segments using tissue Doppler imaging (TDI)and speckle tracking echocardiography (STE) in patients with non-valvular AF with and without LAA thrombus and compared them with SR patients.

Methods

A total of 80 patients with normal left ventricular ejection fraction underwent transesophageal echocardiography (40 patients with SR and 40 patients with AF on oral anticoagulants including patients with LAA thrombus). We analyzed the basal segments of LAA including left lateral ridge (LLR) and baso-medial appendage segment (BMAS). Quantitative analysis was used to calculate peak velocity, average velocity, strain, strain rate and deformation.

Results

In patients with AF the lower LLR strain rate was the sole new STE significant parameter differentiating patients with and without LAA thrombi: − 0.9(− 1.2; − 0.1)s^− 1 vs. − 1.6(− 1.9; − 1.3)s^− 1, (p = 0.004). Additionally, patients in SR demonstrated significantly better peak velocity, average velocity, strain, strain rate and deformation than those with AF (p < 0.001).

Conclusions

LLR appeared to be an appropriate site for measuring Doppler derived parameters. It is possible that the strain rate in LLR area may be a novel parameter correlating with the presence of thrombus in patients with AF.

The differences in left atrial function between ischemic and idiopathic dilated cardiomyopathy patients: A two-dimensional speckle tracking imaging study

PURPOSE

To evaluate left atrial (LA) function in patients with ischemic (ICM) or idiopathic dilated (DCM) cardiomyopathy via two-dimensional speckle-tracking imaging.

METHODS

We measured the LA maximum volume, minimum volume, and volume before the atrial systole, and calculated total emptying volume, expansion index, active emptying volume, and fraction. We measured strain and strain rate during systole and late diastole using two-dimensional speckle-tracking imaging, and analyzed correlations between variables.

RESULTS

We found no significant differences in LA size, left ventricle (LV) end-diastole diameter, LV ejection fraction (EF), E/A, E/e', deceleration time of the E wave, and effective mitral regurgitant orifice area between the DCM and the ICM group. However, the LA expansion index, active EF, systolic and late diastolic strain, and strain rate were lower in the ICM group (p < 0.05). The expansion index and active EF were positively correlated with the systolic strain rate and the absolute value of the late diastolic strain rate, respectively.

CONCLUSIONS

LA basic echocardiographic variables did not reflect the differences between ICM and DCM patients, but the systolic and late diastolic strain, as well as the strain rate, were lower in DCM patients. Two-dimensional speckle-tracking imaging is a promising method to differentiate these patients. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:437-445, 2016.

Prognostic Relevance of Left Atrial Dysfunction in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Left atrial (LA) size is an established marker of risk for adverse outcomes in heart failure with preserved ejection fraction (HFpEF). However, the independent prognostic importance of LA function in HFpEF is not known.

METHODS AND RESULTS

We assessed LA function measured by speckle-tracking echocardiography in 357 patients with HFpEF enrolled in the Treatment Of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist (TOPCAT) trial who were in sinus rhythm at the time of echocardiography. Lower peak LA strain, indicating LA dysfunction, was associated with older age, higher prevalence of atrial fibrillation and left ventricular (LV) hypertrophy, worse LV and right ventricular systolic function, and worse LV diastolic function. At a mean follow-up of 31 months (interquartile range, 18-43months), 91 patients (25.5%) experienced the primary composite end point of cardiovascular death, HF hospitalization, and aborted sudden death. Lower peak LA strain was associated with a higher risk of the composite end point (hazard ratio, 0.96 per unit of reduction in strain; 95% confidence interval, 0.94-0.99; P=0.009) and of HF hospitalization alone (hazard ratio, 0.95 per unit of reduction in strain; 95% confidence interval, 0.92-0.98; P=0.003). The association of LA strain with incident HF hospitalization remained significant after adjustment for clinical confounders, but not after further adjustment for LV global longitudinal strain and the E/E' ratio, parameters of LV systolic and diastolic function, respectively.

CONCLUSIONS

LA dysfunction in HFpEF is associated with a higher risk of HF hospitalization independent of potential clinical confounders, but not independent of LV strain and filling pressure. Impairment in LV systolic and diastolic function largely explains the association between impaired LA function and higher risk of HF hospitalization in HFpEF.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00094302.

Left atrial strain: a new predictor of thrombotic risk and successful electrical cardioversion

BACKGROUND

Left atrial deformation (LAD) parameters are new markers of atrial structural remodelling that seem to be affected in atrial fibrillation (AF) and atrial flutter (AFL). This study aimed to determine whether LAD can identify patients with a higher risk of thrombosis and unsuccessful electrical cardioversion (ECV).

METHODS

Retrospective study including 56 patients with AF or AFL undergoing ECV, with previous transthoracic (TTE) and transoesophageal echocardiography (TEE) studies. Echocardiographic parameters analysed were as follows: left ventricle function, left atrium (LA) dimensions, LAD parameters (positive and negative strain peaks), left atrial appendage (LAA) filling and emptying velocities and the presence of thrombi. Strain values were analysed according to thrombotic risk and success of ECV.

RESULTS

Lower mean values of peak-positive strain (PPS) in patients with prothrombotic velocities (<25 cm/s) and a higher incidence of thrombi in LAA were observed compared with those with normal velocities. Multivariate analysis revealed PPS normalised by LA maximum volume indexed by body surface area (BSA) to be associated with prothrombotic risk (odds ratio 0.000 (95% CI: 0.000-0.243), P 0.017), regardless of CHADs2VASC score. Peak-negative strain normalised by LA volumes indexed by BSA were associated with unsuccessful ECV.

CONCLUSIONS

Atrial deformation parameters identify AF and AFL patients with a high risk of thrombosis and unsuccessful ECV. Therefore, these new parameters should be included in anticoagulation management and rhythm vs rate control strategies.

Assessing the atrial electromechanical coupling during atrial focal tachycardia, flutter, and fibrillation using electromechanical wave imaging in humans

Minimally-invasive treatments of cardiac arrhythmias such as radio-frequency ablation are gradually gaining importance in clinical practice but still lack a noninvasive imaging modality which provides insight into the source or focus of an arrhythmia. Cardiac deformations imaged at high temporal and spatial resolution can be used to elucidate the electrical activation sequence in normal and paced human subjects non-invasively and could potentially aid to better plan and monitor ablation-based arrhythmia treatments. In this study, a novel ultrasound-based method is presented that can be used to quantitatively characterize focal and reentrant arrhythmias. Spatio-temporal maps of the full-view of the atrial and ventricular mechanics were obtained in a single heartbeat, revealing with otherwise unobtainable detail the electromechanical patterns of atrial flutter, fibrillation, and tachycardia in humans. During focal arrhythmias such as premature ventricular complex and focal atrial tachycardia, the previously developed electromechanical wave imaging methodology is hereby shown capable of identifying the location of the focal zone and the subsequent propagation of cardiac activation. During reentrant arrhythmias such as atrial flutter and fibrillation, Fourier analysis of the strains revealed highly correlated mechanical and electrical cycle lengths and propagation patterns. High frame rate ultrasound imaging of the heart can be used non-invasively and in real time, to characterize the lesser-known mechanical aspects of atrial and ventricular arrhythmias, also potentially assisting treatment planning for intraoperative and longitudinal monitoring of arrhythmias.

Left Atrial Longitudinal Speckle Tracking Echocardiography in Healthy Aging Heart

Background:

Left atrial volume (LAV) and function are connected to the left ventricular (LV) haemodynamic patterns. To define the changes of LAV and functions to counterbalance age-related LV diastolic impairment, this study was undertaken.

Methods:

2D-Left Atrial Speckle Tracking Echocardiography (2D-LASTE) was used to define both LAV and functions in an aged healthy population (group II) respect to adult healthy controls (group I).

Results:

Results showed an increasing of left atrial volume indices (LAVI) (maximum, minimum, pre-a) in old subjects in comparison with those obtained in adult healthy controls. On the contrary, LAVI passive emptying unchanged and LAVI passive fraction reduced with advanced age. Finally, LAVI active emptying increased with advancing age to compensate the age-dependent left ventricular diastolic dysfunction. The values of global systolic strain (S); systolic strain rate (SrS); early diastolic strain rate (SrE), and late diastolic strain rate (SrA) were also calculated. With reference to the function, our study confirmed that LA conduit function deteriorates with age while booster pump increases respect to adult controls and reservoir phase is maintained.

Conclusions:

The echocardiographic findings obtained with conventional and tissue Doppler confirmed the connection between LA functions and volumes and age-related LV dysfunction. Conclusively, 2D-LASTE appears to be a reliable tool to evaluate the role of LA to compensate the derangement of left ventricle happening with ageing.

Left atrial geometry and pump function in ischemic cardiomyopathy

Background

Many of the factors that are known to alter left atrial (LA) contractility are present in patients with ischemic cardiomyopathy (ICM). Nevertheless, preservation of LA contractile function in this group of patients was reported in previous studies. The aim of this study was to assess the changes in LA size, geometry and contractile function in ICM.

Methods and results

60 subjects (age: 49 ± 12 years, 53% males) in sinus rhythm undergoing coronary angiography (CA), were enrolled in this study; 15 subjects as a control group, 30 patients with reduced ejection fraction (EF) and significant coronary artery disease; as the ICM group, and 15 with reduced EF and normal CA; as the dilated cardiomyopathy (DCM) group.

LA dimensions, volume, active emptying fraction (ACTEF) and eccentricity index (LAEi) as well as late diastolic velocities of the mitral annulus (a′) and LA free wall (A₃) were measured.

Compared with the control group, ICM patients had larger LA volume and reduced ACTEF, a′ and A₃, with no significant difference between patients with ICM and DCM in any of these parameters. LA eccentricity was, non-significantly, higher in both cardiomyopathy groups than in the control group.

Conclusions

Patients with ICM have increased LA volume and reduced LA contractile function in comparison with normal controls. LA enlargement, LA contractile dysfunction and LA geometric changes in ICM are similar to that occurring in DCM. LA size, contractile function and eccentricity may not be reliable in differentiating ischemic from idiopathic dilated cardiomyopathy.

Impaired left atrial function in heart failure with preserved ejection fraction

AIMS

Left atrial (LA) enlargement is present in the majority of heart failure with preserved ejection fraction (HFpEF) patients and is a marker of risk. However, the importance of LA function in HFpEF is less well understood.

METHODS AND RESULTS

The PARAMOUNT trial enrolled HFpEF patients (LVEF ≥45%, NT-proBNP >400 pg/mL). We assessed LA reservoir, conduit, and pump function using two-dimensional volume indices and speckle tracking echocardiography in 135 HFpEF patients in sinus rhythm at the time of echocardiography and 40 healthy controls of similar age and gender. Systolic LA strain was related to clinical characteristics and measures of cardiac structure and function. Compared with controls, HFpEF patients had worse LA reservoir, conduit, and pump function. The differences in systolic LA strain (controls 39.2 ± 6.6% vs. HFpEF 24.6 ± 7.3%) between groups remained significant after adjustments and even in the subsets of HFpEF patients with normal LA size or without a history of AF. Among HFpEF patients, lower systolic LA strain was associated with higher prevalence of prior HF hospitalization and history of AF, as well as worse LV systolic function, and higher LV mass and LA volume. However, NT-proBNP and E/E' were similar across the quartiles of LA function.

CONCLUSIONS

In this HFpEF cohort, we observed impairment in all phases of LA function, and systolic LA strain was decreased independent of LA size or history of AF. LA dysfunction may be a marker of severity and play a pathophysiological role in HFpEF.

TRIAL REGISTRATION

NCT00887588.

Speckle echocardiographic left atrial strain and stiffness index as predictors of maintenance of sinus rhythm after cardioversion for atrial fibrillation: a prospective study

Background

Echocardiographic left atrial (LA) strain parameters have been associated with atrial fibrillation (AF) in prior studies. Our goal was to determine if strain measures [peak systolic longitudinal strain (LAS) and stiffness index (LASt)] changed after cardioversion (CV); and their relation to AF recurrence.

Methods and results

46 participants with persistent AF and 41 age-matched participants with no AF were recruited. LAS and LASt were measured before and immediately after CV using 2D speckle tracking imaging (2DSI). Maintenance of sinus rhythm was assessed over a 6-month follow up. Mean LAS was lower, and mean LASt higher, in participants with AF before CV as compared to control group (11.9 ± 1.0 vs 35.7 ± 1.7, p<0.01 and 1.31 ± 0.17 vs 0.23 ± 0.01, p<0.01, respectively). There was an increase in the mean LAS immediately after CV (11.9 ± 1.0 vs 15.9 ± 1.3, p<0.01), whereas mean LASt did not change significantly after CV (p=0.62). Although neither LAS nor LASt were independently associated with AF recurrence during the follow-up period, change in LAS after cardioversion (post-CV LAS – pre-CV LAS) was significantly higher among individuals who remained in sinus rhythm when compared to individuals with recurrent AF (3.6 ± 1.1 vs 0.4 ± 0.8, p=0.02).

Conclusions

LAS and LASt differed between participants with and without AF, irrespective of the rhythm at the time of echocardiographic assessment. Baseline LAS and LASt were not associated with AF recurrence. However, change in LAS after CV may be a useful predictor of recurrent arrhythmia.

The Role of Echocardiography as a Predictor of the Incidence and Progression of Atrial Fibrillation

Atrial fibrillation is the most frequent sustained arrhythmia and is an independent risk factor for stroke and death. In recent years, major echocardiographic advances have been made with the development of new techniques and applications that can be extremely useful for the management of these patients. This paper describes the role of echocardiography as a predictor of the incidence and progression of atrial fibrillation. A detailed description of the most relevant studies and recognition of unresolved questions regarding this subject are presented here. A special emphasis will be given on new techniques that allow the assessment of myocardial deformation and their possible role in the way we treat these patients.

Acute effects of right ventricular apical pacing on left atrial remodeling and function

BACKGROUND

The acute effects of right ventricular apical (RVA) pacing on left atrial (LA) function in patients with normal ejection fraction are not clear.

METHODS

A total of 94 patients (age 68.1 ± 11.1 years, 26 men) with implanted RVA-based dual-chamber pacemakers were recruited into this study. Patients who were pacemaker-dependent, in persistent atrial fibrillation or left ventricular ejection fraction <45% were excluded. Echocardiography (iE33, Philips, Andover, MA, USA) was performed during intrinsic ventricular conduction (V-sense) and RVA pacing (V-pace) with 15 minutes between switching modes. The total maximal LA volume (LAV(max)), preatrial contraction volume (LAV(pre)), and minimal volume (LAV(min)) were assessed by area-length method. Peak systolic, early diastolic, and peak late diastolic (atrial contractile) velocity (Sm-la, Em-la, and Am-la) and strain (ɛs-la, ɛe-la, and ɛa-la) were measured by color-coded tissue Doppler imaging (TDI) in four mid-LA walls at apical four- and two-chamber views.

RESULTS

During V-pace, LA volumes increased significantly compared with V-sense (LAV(max): 52.0 ± 18.8 vs 55.2 ± 21.1 mL, P = 0.005; LAV(pre): 39.8 ± 16.4 vs 41.3 ± 16.6 mL, P = 0.014; LAV(min): 27.4 ± 14.0 vs 29.1 ± 15.1 mL, P = 0.001). TDI parameters showed significant reduction in Sm-la and Em-la. Furthermore, ɛs-la, ɛe-la, and ɛa-la decreased significantly, especially in patients with preexisting diastolic dysfunction (all P < 0.01).

CONCLUSIONS

RVA pacing acutely induced LA enlargement and impaired atrial contractility. Patients with preexisting diastolic dysfunction may be more vulnerable to develop LA dysfunction and remodeling after acute RVA pacing.

Left atrial function: physiology, assessment, and clinical implications

The interest in the left atrium (LA) has resurged over the recent years. In the early 1980s, multiple studies were conducted to determine the normal values of LA size. Over the past decade, LA size as an imaging biomarker has been consistently shown to be a powerful predictor of outcomes, including major public health problems such as atrial fibrillation, heart failure, stroke, and death. More recently, functional assessment of the LA has been shown to be, at least as, if not more robust, a marker of cardiovascular outcomes. Current available data suggest that the combined evaluation of LA size and LA function will augment prognostication. The aim of this review is to provide a critical appraisal of current echocardiographic techniques for the assessment of LA function and the implications of such assessment for prediction and disease prevention.