Left Function Research Articles

Effect of Blood Pressure Control on Left Atrial Function Assessed by 2D Echocardiography in Newly Diagnosed Patients with Systemic Hypertension

Effect of Blood Pressure Control on Left Atrial Function Assessed by 2D Echocardiography in Newly Diagnosed Patients with Systemic Hypertension

Abstract 4125500: Obesity-Related Left Atrial Functional Change Becomes Apparent in Infancy

Background: Impaired left atrial (LA) function is observed in obese patients, however, there is little information on when LA dysfunction begins to appear. To clarify this issue, we assessed LA volume and function in obese infants. Methods: Two-dimensional speckle-tracking echocardiography was performed in 96 infants aged 4 months. Subjects were divided into 3 groups according to body mass index (BMI): normal (n=53), <17 kg/m 2 ; overweight (n=28), 17 to 19.9 kg/m 2 ; obese (n=15), ≧20 kg/m 2 . LA maximal volume, LA minimal volume, and LA pre-atrial contraction volume and LA longitudinal strain (reservoir, conduit, and booster) were measured. LA total emptying fraction, passive emptying fraction, and active emptying fraction were calculated. Results: Systolic blood pressure was significantly higher in the obese group than in the normal group (Table). LA maximal volume, minimal volume, and pre-atrial contraction volume increased significantly with increasing BMI (r = 0.53, 0.54, and 0.63, respectively, p <0.01). Compared with the normal group, reservoir LA strain was significantly lower in the overweight and obese groups. Conduit LA strain and passive emptying fraction were significantly lower in the overweight and obese groups than those in the normal group (Table). Reservoir LA strain, conduit LA strain, and passive emptying fraction decreased significantly with increasing BMI (r = -0.28, -0.27, and -0.33, respectively, p <0.01). There was no significant difference in booster LA strain among the 3 groups. Compared with the normal group, LA active emptying fraction was significantly higher in the obese group (Table). Conclusions: Higher BMI is associated with impaired reservoir and conduit LA function and higher booster LA pump function, which may be compensatory. Thus, obesity-related changes in LA functional begin to appear in infancy. Our data support prevention of obesity in early childhood because higher BMI is responsible for significant changes in LA function in early life.

Abstract 4145861: Systemic Sclerosis is Associated with Sub-Clinical Abnormalities in Myocardial Energetics, Perfusion and Increased Fibrosis

Background: Primary cardiac involvement in systemic sclerosis (SSc) is heterogenous, poorly defined and associated with significant cardiac morbidity and mortality. The underlying mechanism is not well understood but may include the impact of coronary microvascular dysfunction and myocardial inflammation. Myocardial cellular metabolic alterations in SSc are yet to be established. Aims: Using 31 Phosphorous magnetic resonance spectroscopy ( 31 P MRS) and cardiovascular magnetic resonance (CMR), we aimed to establish if myocardial energetics, measured as phosphocreatine (PCr) /ATP ratio, and quantitative myocardial perfusion were reduced in individuals with SSc compared to healthy volunteers (HV). Methods: A total of 35 age and sex matched participants were recruited (25 SSc, 10 HV). All subjects underwent 31 P MRS and comprehensive CMR protocol including volumetric analysis, quantitative myocardial perfusion and T1 mapping. Results: Table-1 shows clinical and CMR / 31 P MRS data. Bi-ventricular volumes, systolic function and left atrial function were similar in both groups. NT-Pro BNP and myocardial extra cellular volume (ECV) were significantly increased in SSc. Both PCr/ATP and myocardial perfusion reserve (MPR) were significantly reduced in SSc compared with controls. The disease activity as measured by the European Scleroderma Trials and Research group (EUSTAR) activity index did not correlate with either NTproBNP (P=0.79), PCr/ATP (P=0.35) or MPR (P=0.6). Conclusions: In addition to validating our previous observations of reduced perfusion and increased myocardial fibrosis in SSc, we have demonstrated for the first time significant reductions in myocardial energetics in patients with SSc. These findings provide further valuable insight into the pathogenesis of primary myocardial disease in SSc.

Left Atrial Structure and Function Following Ethanol Infusion into Vein of Marshall (MR-SHALL Study).

Ethanol infusion into the vein of Marshall (EI-VOM) is an adjunctive therapy to pulmonary vein isolation (PVI), which improves the efficacy of persistent atrial fibrillation (AF) ablation procedures. It is unknown how EI-VOM scar formation impacts left atrium (LA) structure and function. To characterize scar formation after EI-VOM, and its impact on LA function, by cardiac magnetic resonance (CMR). Consecutive patients referred for persistent AF ablation, or any repeat procedure, were included. Ablation strategy included PVI, EI-VOM and linear lesions when deemed necessary. LA was assessed by late gadolinium enhancement (LGE) CMR at baseline and 3-month follow-up. CMR was post-processed off-line with dedicated software. The LA was regionalized into 17 segments, and global and regional scarring were calculated. Strain parameters were analyzed-including LA reservoir, conduit, and booster strain; LA ejection fraction; and LA passive and active emptying function. Follow-up LGE-CMR reconstruction was coregistered with the voltage map, ablation RF points, and fluoroscopy to compare the scar location with the VOM trajectory. This study included 21 patients (65 ± 8 years; 76% men; 57% ablation of persistent AF). After EI-VOM, 95% of patients presented new low-voltage areas, all of whom exhibited new LGE-CMR scarring at follow-up. Voltage map and LGE-CMR coregistration showed comparable scar areas (p = 0.287). LGE-CMR scarring frequently involved the whole VOM trajectory, predominantly affecting the LA ridge, mitral isthmus, and left posterior wall. LA volume was significantly reduced after ablation, without significant changes in LA functional parameters. EI-VOM causes permanent scarring at 3-month follow-up, with no adverse impact on CMR LA functional parameters.

Multiphysics simulations reveal haemodynamic impacts of patient-derived fibrosis-related changes in left atrial tissue mechanics.

Stroke is a leading cause of death and disability worldwide. Atrial myopathy, including fibrosis, is associated with an increased risk of ischaemic stroke, but the mechanisms underlying this association are poorly understood. Fibrosis modifies myocardial structure, impairing electrical propagation and tissue biomechanics, and creating stagnant flow regions where clots could form. Fibrosis can be mapped non-invasively using late gadolinium enhancement magnetic resonance imaging (LGE-MRI). However, fibrosis maps are not currently incorporated into stroke risk calculations or computational electro-mechano-fluidic models. We present multiphysics simulations of left atrial (LA) myocardial motion and haemodynamics using patient-specific anatomies and fibrotic maps from LGE-MRI. We modify tissue stiffness and active tension generation in fibrotic regions and investigate how these changes affect LA flow for different fibrotic burdens. We find that fibrotic regions and, to a lesser extent, non-fibrotic regions experience reduced myocardial strain, resulting in decreased LA emptying fraction consistent with clinical observations. Both fibrotic tissue stiffening and hypocontractility independently reduce LA function, but, together, these two alterations cause more pronounced effects than either one alone. Fibrosis significantly alters flow patterns throughout the atrial chamber, and particularly, the filling and emptying jets of the left atrial appendage (LAA). The effects of fibrosis in LA flow are largely captured by the concomitant changes in LA emptying fraction except inside the LAA, where a multifactorial behaviour is observed. This work illustrates how high-fidelity, multiphysics models can be used to study thrombogenesis mechanisms in patient-specific anatomies, shedding light onto the links between atrial fibrosis and ischaemic stroke. KEY POINTS: Left atrial (LA) fibrosis is associated with arrhythmogenesis and increased risk of ischaemic stroke; its extent and pattern can be quantified on a patient-specific basis using late gadolinium enhancement magnetic resonance imaging. Current stroke risk prediction tools have limited personalization, and their accuracy could be improved by incorporating patient-specific information such as fibrotic maps and haemodynamic patterns. We present the first electro-mechano-fluidic multiphysics computational simulations of LA flow, including fibrosis and anatomies from medical imaging. Mechanical changes in fibrotic tissue impair global LA motion, decreasing LA and left atrial appendage (LAA) emptying fractions, especially in subjects with higher fibrosis burdens. Fibrotic-mediated LA motion impairment alters LA and LAA flow near the endocardium and the whole cavity, ultimately leading to more stagnant blood regions in the LAA.

Left atrial function during exercise stress echocardiography as a sign of paroxysmal/persistent atrial fibrillation

ObjectiveAtrial cardiomyopathy is closely associated with atrial fibrillation (AF), and some patients exhibit no dysfunction at rest but demonstrate evident changes in left atrial (LA) function and LA volume during exercise. This study aimed to identify distinguishing signs during exercise stress echocardiography (ESE) among patients in sinus rhythm (SR), with and without history of paroxysmal/persistent AF (PAF).MethodsA prospective cohort of 1055 patients in SR was enrolled across 12 centers. The main study cohort was divided into two groups: the modeling group (n = 513) and the verification group (n = 542). All patients underwent ESE, which included B-lines, LA volume index (LAVi), and LA strain of the reservoir phase (LASr).ResultsAge, resting and stress LAVi and LASr, and B-lines were identified as a combination of detectors for PAF in both groups. In the entire cohort, aside from resting and stress LAVi and LASr, additional parameters differentiating PAF and non-PAF patients were the presence of systemic hypertension, exercise E/e’ > 7, worse right ventricle (RV) contraction during exercise (∆ tricuspid annular plane systolic excursion < 5 mm), a lower left ventricular contractile reserve (< 1.6), and a reduced chronotropic reserve (heart rate reserve < 1.64). The composite score, summing all 9 items, yielded a score of > 4 as the best sensitivity (79%) and specificity (65%).ConclusionESE can complement rest echocardiography in the identification of previous PAF in patients with SR through the evaluation of LA functional reservoir and volume reserve, LV chronotropic, diastolic, and systolic reserve, and RV contractile reserve.Graphical A scoring system predicting the probability of PAF. The score was computed using the cutoff values as in the illustration. The score >4 demonstrated a sensitivity of 79% and a specificity of 65% of PAF.

Preoperative left atrial size and functions are predictors of left atrial reverse remodelling after mitral valvuloplasty for myxomatous mitral valve disease in dogs

ObjectivesThe objective of this study was to determine alterations in left atrial size, function, and determinants of left atrial reverse remodelling (LARR) after mitral valvuloplasty (MVP) in dogs with myxomatous mitral valve disease (MMVD). AnimalsThirty-seven dogs undergoing MVP. Materials and MethodsEchocardiographic parameters, including left atrial (LA) strain, were evaluated at baseline, during the early postoperative period (within two weeks), and at one and three months postoperatively. Patients were divided into two groups based on the attainment of LARR, defined as a left atrial to aortic root ratio (LA:Ao) < 1.6 at three months. The predictors of LARR were analysed using univariate logistic regression analysis. ResultsLA:Ao significantly decreased in the early postoperative period (median 1.68; lower and upper quartile 1.54–1.92) compared to baseline (2.41; 2.00–2.80), with a further significant reduction observed at three months (1.46; 1.34–1.63). LARR was achieved in 27 (73%) patients. Baseline LA:Ao was higher, and peak atrial longitudinal strain (PALS) and peak atrial construction strain (PACS) were lower in the non-LARR group than in the LARR group. Among the baseline parameters, PACS was the strongest predictor of LARR (area under the curve, 0.837). ConclusionsFollowing MVP, the LA size decreased in the early postoperative period and continued to decrease over three months of follow-up. A low PACS score was the most reliable predictor of inadequate LARR. Further studies are necessary to determine the relationship between LARR, prognosis, and the optimal timing for surgical intervention.

Atrial fibrillation substrate and impaired left atrial function: a cardiac MRI study.

Structural and fibrotic remodelling is a well-known contributor to the atrial fibrillation (AF) substrate. Epicardial adipose tissue (EAT) is increasingly recognized as a contributor through electrical remodelling in the atria. We aimed to assess the association of LA fibrosis and EAT with LA strain and function using cardiac magnetic resonance (CMR) imaging in patients with AF. LA fibrosis was assessed using late gadolinium enhancement CMR, LA EAT was assessed using the fat-water separation Dixon sequence, and feature tracking was applied to assess global longitudinal strain in its three components [reservoir (GLRS), conduit (GLCdS), and contractile (GLCtS)]. LA emptying fraction and LA volume were measured using the cine sequences. All CMR images were acquired in sinus rhythm. One hundred one AF patients underwent pre-ablation CMR (39% female, average age 62 years). LA fibrosis was negatively associated with the three components of global longitudinal strain (GLRS: R = -0.35, P < 0.001; GLCdS: R = -0.24, P = 0.015; GLCtS: R = -0.2, P = 0.046). Out of the different sections of the LA, fibrosis in the posterior and lateral walls was most negatively correlated with GLRS (R = -0.32, P = 0.001, and R = -0.33, P = 0.001, respectively). LA EAT was negatively correlated with GLCdS (R = -0.453, P < 0.001). LA fibrosis was negatively correlated with LA emptying fraction but LA EAT was not (R = -0.27, P = 0.007, and R = -0.22, P = 0.1, respectively). LA EAT and fibrosis were both positively correlated with LA volume (R = 0.38, P = 0.003, and R = 0.24, P = 0.016, respectively). LA fibrosis, a major component of the AF substrate, and EAT, an important contributor, are associated with a worsening LA function through strain analysis by CMR.

Left atrial functional changes associated with repeated catheter ablations for atrial fibrillation.

The impact of repeated atrial fibrillation (AF) ablations on left atrial (LA) mechanical function remains uncertain, with limited long-term follow-up data. This retrospective study involved 108 AF patients who underwent two catheter ablations with cardiac magnetic resonance imaging (MRI) done before and 3 months after each of the ablations from 2010 to 2021. The rate of change in peak longitudinal atrial strain (PLAS) assessed LA function. Additionally, a sub-study of 36 patients who underwent an extra MRI before the second ablation, gave us an additional time segment to evaluate the basis of change in PLAS. In the two-ablation, three MRI sub-study 1, the PLAS percent change rate was similar before and after the first ablation (r11 = -0.9 ± 3.1%/year, p = 0.771). However, the strain change rate from postablation 1 to postablation 2 was significantly worse (r12 = -23.7 ± 4.8%/year, p < 0.001). In the sub-study 2 with four MRIs, all three rates were negative, with reductions from postablation 1 to pre-ablation 2 (r22 = -13.3 ± 2.6%/year, p < 0.001) and from pre-ablation 2 to postablation 2 (r23 = -8.9 ± 3.9%/year, p = 0.028) being significant. The present study suggests that the more ablations performed, the more significant the decrease in the postablation mechanical function of the LA. The natural progression of AF (strain change from postablation 1 to pre-ablation 2) had a greater negative influence on LA mechanical function compared to the second ablation itself suggesting that second ablation in patients with recurrence after first ablation is an effective strategy even from the LA mechanical function aspect.

Left atrial function in uraemic patients: Four-dimensional automatic left atrial quantitative technology study.

This study aimed to evaluate the utility of left atrial volume and function in uraemic patients using four-dimensional automatic left atrial quantification (4D auto LAQ) technology. Thirty-four undialysed uraemic patients (U-ND group), 60 dialysed uraemic patients (U-D group), and 32 healthy volunteers (N group) were enrolled in our current study. Conventional echocardiographic parameters were recorded, and left atrial volume and strain parameters were analysed to determine statistical differences among the three groups. The Pearson correlation coefficient was employed to assess the relationships between left atrial ejection fraction and left atrial strain parameters. Compared to the N group, uraemic patients often displayed left atrial enlargement and left ventricular hypertrophy. Significant increases were noted in left atrial diameter, interventricular septum thickness, left ventricular posterior wall thickness, E/e', diastolic blood pressure, systolic blood pressure, left atrial minimum volume, left atrial maximum volume, left atrial pre-atrial contraction volume, left atrial emptying volume and left atrial maximum volume index (P<0.05). Conversely, the e', E/A ratio and left atrial reservoir longitudinal strain were significantly decreased (P<0.05). However, no statistically significant differences were observed in the aforementioned parameters between the U-ND and U-D groups. The absolute values of left atrial conduit longitudinal strain and left atrial conduit circumferential strain, as well as left atrial passive ejection fraction, were notably lower in the U-D group compared to the N and U-ND groups, with statistically significant differences identified among the three groups (P<0.05). Uraemic patients exhibit marked left atrial enlargement and left ventricular hypertrophy, coupled with altered atrial function, particularly ductal dysfunction in the U-D group. The 4D auto LAQ technology proves advantageous in detecting these alterations, offering a promising tool for thorough cardiac assessment in this patient cohort.

Improvement of left atrial function after ablation in patients with paroxysmal atrial fibrillation is associated with the presence of heart failure with preserved ejection fraction

Abstract Background Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) often coexist and left atrial (LA) function was impaired in both AF and HFpEF. However, It remains unclear if HFpEF is linked to LA function improvement in paroxysmal atrial fibrillation (pxAF) patients post-ablation. Purpose To investigate whether the improvement of LA function after ablation in patients with pxAF combined with HFpEF is better than that in patients without HFpEF. Methods 147 patients with pxAF were enrolled and HFpEF was ascertained based on the H2FPEF score. All patients underwent transthoracic echocardiography (TTE) at baseline and 3 months after ablation. Left atrial volume index (LAVI), left atrial ejection fraction (LAEF) and left atrial peak reservoir strain (LA RS) were measured. Improvement of left atrial function is defined as the difference in the above 3 indicators at baseline and 3 months after ablation. The change of the above atrial functional parameters was compared between patients with high-probability of HFpEF [hp-HFpEF] and medium/low-probability of HFpEF [lp-HFpEF]) in univariate and multivariate analysis. Statistical analyses were conducted using independent samples t-tests, Mann-Whitney U tests, and ANCOVA. Results 147 patients were included (30 hp-HFpEF, 117 lp-HFpEF, mean age 62.6 years, 63.3% men, mean BMI 25.54kg/㎡, mean disease course 28.2 months, mean CHA2DS2-VASc score 1.97). In the univariate analysis, the following factors were significantly different between hp-HFpEF and lp-HFpEF, including BMI (26.95±3.71 vs. 25.18±3.00, p=0.007), CHA2DS2-VASc score (3[3-4] vs. 2[1-2], p＜0.001), LA function at baseline including LAVI (41.59±11.38 vs. 32.57[27.68-41.10], p=0.003), LAEF (45.97±10.26 vs. 57.23±9.08, p＜0.001), LA RS (26.43±10.68 vs. 34.43±10.60, p＜0.001), and difference at baseline and 3 months after ablation in LA function including LAVI (4.92±1.08 vs. 3.33±1.18, p＜0.001), LAEF (13.41±9.71 vs. 2.98±9.69, p＜0.001), LA RS (23.61±10.23 vs. 7.29±6.91, p＜0.001), and in left ventricular (LV) TTE indicators including E/e’ (3.10±2.30 vs. -0.32±2.68, p＜0.001), LV ejection fraction (10.5[7.0-16.5] vs. 2.0[-5.0-6.0], p＜0.001), LV global longitudinal strain (14.94±4.27 vs. 5.15[2.63-8.30], p＜0.001) and LV mass (17.79±28.67 vs 1.50[-8.75-17.00], p=0.006). After adjusted for BMI, CHA2DS2-VASc score, LA function at baseline and difference at baseline and 3 months after ablation in LV TTE indicators, the improvement of LA function 3 months after ablation in patients with hp-HFpEF is better than that in patients with lp-HFpEF: LAVI significantly decreased (4.24±0.21 vs. 3.46± 0.09, p＜0.001), LAEF significantly increased (12.90±2.13 vs. 3.09±0.86, p＜0.001) and LA RS significantly increased (21.44±1.81 vs. 8.02±0.76, p＜0.001) in hp-HFpEF compared with lp-HFpEF. Conclusion Patients with pxAF with hp-HFpEF showed better improvement in LA function after ablation than those with Ip-HFpEF.

How different types of cardiomyopathy with hypertrophic phenotype affect left atrial remodeling and function

Abstract Background Left atrial (LA) dysfunction is a common feature in hypertrophic cardiomyopathies. How the underlying etiology and pathophysiology of different cardiomyopathies affects LA remodeling and function remains unexplored. Purpose The aim of our study is to investigate the influence of various cardiomyopathies with hypertrophic phenotype on LA remodeling and function. Methods Patients with left ventricular (LV) hypertrophic phenotype who underwent cardiac magnetic resonance (CMR) were included. A group of patients with a normal CMR was included as a control group. CMR acquisitions used for clinical indication of heart failure diagnosis and etiology were retrospectively analyzed to obtain LA reservoir, conduit, and booster strain, left atrioventricular coupling index (LACI) and LA sphericity. Differences between groups were assessed. To investigate the independent clinical associates of LA reservoir, conduit and booster strain, multivariable linear regression analyses were performed. Results A total of 375 individuals were analyzed including 321 patients diagnosed with LV hypertrophy and 54 patients with a normal CMR. Of the 321 patients with LV hypertrophy, 148 were diagnosed with hypertrophic cardiomyopathy (HCM), 35 with cardiac amyloidosis (CA), 41 with hypertensive cardiomyopathy (HTN) and 97 with severe asymptomatic aortic stenosis (AS). CMR LA characteristic and strain analysis results are summarized in Figure 1. The indexed LA end-systolic volume (iLAVmax), indexed LA end-diastolic volume (iLAVmin) and LA sphericity were larger in patients with CA when compared to other groups (all p&amp;lt;0.05). CA patients displayed more left atrioventricular uncoupling (lower LACI) when compared to individuals with HCM, HTN, AS, and controls (all p&amp;lt;0.001), while no significant differences were observed across other groups. CA patients exhibited lower LA reservoir and booster strains compared to the other groups (all p&amp;lt;0.05), whereas no significant differences were observed across other hypertrophic phenotype diseases. Age, iLAVMax and LACI were independently associated with all the three LA strain components (Figure 2, all p&amp;lt;0.05). Conclusions LA remodeling and function are affected differently across the various etiologies of LV hypertrophy. CA patients exhibit more pronounced atrial involvement, whereas those with HCM, asymptomatic AS, and HTN display similar patterns of atrial dysfunction and remodeling. Additionally, CMR-derived iLAVmax and LACI are independently correlated with LA function.

Decreased left atrial volume and preserved left atrial function in children with congenital Zika syndrome

Abstract Introduction The infection caused by Zika virus during pregnancy leads to congenital Zika syndrome (CZS). In a previous study of our group, we found that the heart is smaller in children with CZS, with few functional alterations. Left atrial strain imaging enables quantitative assessment of left atrial function, and recently its application has also shown promise in the pediatric population. Purpose To evaluate left atrial function in children affected by CZS, using echocardiogram and speckle tracking imaging technique. Methods This observational study was conducted with children with CZS using a two-dimensional speckle tracking technique to measure left atrial reservoir strain (LAS-r), conduit strain (LAS-cd), and contraction strain (LAS-ct). Also, to investigate the relationship between LAS-r and systolic excursion of the septum and lateral mitral annular plane (MAPSE), left atrial volume index and E/e’ ratio. Results A total of 52 patients were included, the median age of the studied population was 5 years (3 to 6), 59.6% male, and the body surface area was 0.66 [0.51, 0.90]. In the echocardiographic evaluation the left atrium volume index (ml/m²) was 13.15 [6.80, 18.00], considered smaller by the reference value. Also, the LAS-r (%) was 40.99 [24-70.5], LAS-cd (%) was 30,94 [32.5-52.5], LAS-cd (%) was 10,91 [5.2-24], values considered normal by the literature. Lateral MAPSE (cm) was 1.25 [0.81, 1.86] and septal MAPSE (cm) was 0.98 [0.78, 1.66] and E/e' ratio was 7.52 [4.57, 10.78]. A positive linear correlation was found between LAS-r and lateral MAPSE (r = 0.51, P = 0.019). Conclusion This original study with children with CZS shows that despite reduced atrial volume, the left atrial function remains normal, and correlates with left ventricular function evaluated by MAPSE. Further studies are needed to prospectively analyze the follow-up of left atrial morphology and function in this population.

Atrial function after cardioversion in patients with persistent atrial fibrillation

Abstract Background After cardioversion for persistent atrial fibrillation (AF), restitution of normal left atrial (LA) function is said to need several days to recover. However, in previous studies, the evaluation of LA function was only used transesophageal or transthoracic echocardiography. During catheter ablation (CA) for AF, pulmonary venous (PV) blood flow can be measured accurately using an intracardiac echocardiogram (ICE). The atrial systolic PV regurgitation (PVa) wave measured by ICE is a good indicator of LA contractility because it reflects the active contraction of the LA. Purpose This study aims to investigate the LA function in the hyperacute phase and the factors which affect after cardioversion. Methods 40 AF patients (18 paroxysmal AF, 22 persistent AF) who underwent CA were enrolled. PVa wave was measured twice before RFCA and after the procedure using intracardiac ultrasound. Voltage map of the LV was obtained using the CARTO system at the end of the session, and the percentage of low voltage area which was determined area as less than 0.1mV in the mapped LA surface area (LVA%) was calculated. Results Preoperative PVa was 1.61 ± 0.09 m/sec in the paroxysmal AF group (PaAF), and no PVa was observed in the persistent AF group (PeAF). Postoperative PVa were comparable between PaAF (0.18±0.06 m/sec) and PeAF (0.18±0.07 m/sec). Then, the PeAF were divided into 2 groups based on LVA% in the anterior area, posterior area, and total LA area (cutoff 1,5 and 10%, respectively). In the anterior lower LVA% group, PVa were significantly increased (0.20 ± 0.07 m/sec) after defibrillation compared with the anterior higher LVA% group (0.14 ± 0.06 m/sec; P=0.02), whilst no difference was observed when it was divided in the posterior wall or overall. Conclusion Even in PeAF, LA function improves to the same degree as in the PaAF immediately after cardioversion, and the posterior wall LVA, including posterior wall isolation, may not affect LA function.

Left atrial function for predicting atrial fibrillation: a machine learning approach

Abstract Background Common risk scores for atrial fibrillation (AF) are based on clinical risk factors, and little is known about the contribution of left atrial (LA) function parameters to risk assessment. Purpose To determine whether a machine learning-based model that includes LA function parameters outperforms a commonly used risk scores, the CHARGE-AF, in predicting AF. Methods Participants in the Atherosclerosis Risk in Communities (ARIC) Study (a community-based cohort study in the USA) who attended visit 5 (2011-2013) and without a history of AF were included in this analysis. Incident AF was ascertained from ECG during study visits, hospitalization discharge codes, and death certificates. Random survival forest methodology was used to build a prediction model for AF; candidate variables included traditional clinical risk factors and measures of LA structure and function. Dataset was randomly split into a training (75%) and testing (25%) cohort. For each variable, importance was measured based on the reduction in Harrell’s c-statistic if the variable was randomly permuted prior to obtaining predicted values. Variables significantly associated with AF were included in the final model. Model calibration was tested using the Greenwood-Nam-D'Agostino (GND) test. Discrimination ability of our model was assessed in the testing cohort using Harrell’s c-statistic and compared with that of the CHARGE-AF model. Results 4,909 participants (59% female, 22% Black, mean age 75 years) were included. During a median follow-up of 7.0 years (1st-3rd quartile: 5.4-7.8), 650 participants developed AF. Variables significantly associated with incident AF were race, triglycerides, systolic blood pressure, coronary heart disease, age, LA maximal volume index, NT-proBNP, and LA reservoir strain (Figure 1). LA reservoir strain was the variable most strongly associated with AF. The final model showed good discrimination (c-statistic (95% CI): 0.734 (0.698-0.768)). The GND test did not detect statistically significant miscalibration (GND p=0.08). Compared with our model, CHARGE-AF had lower discrimination ability (c-statistic (95% CI): 0.635 (0.594-0.677)) and the difference was statistically significant (difference in c-statistic (95% CI): 0.099 (0.043-0.152)). Conclusion A machine learning-based model with few variables including LA function outperforms a commonly used risk model in predicting AF. Incorporation of LA functional assessment may help inform clinicians regarding individual risk of AF.

Left atrial longitudinal strain behavior in patients with cryptogenic stroke - a case control study

Abstract Background A significant percentage of ischemic strokes classified as cryptogenic stroke (CS) where the definition is varied according to the type of classification used. Left atrial (LA) function has a role in determining the possible cardio-embolic source of stroke. Using speckle tracking transthoracic echocardiography (TTE) we can detect the early changes in left atrial function by measuring left atrial longitudinal strain (LALS). Aim To evaluate the left atrial stain in patients with a cryptogenic stroke as compared to a healthy papulation. Method and results We recruited 50 cryptogenic ischemic stroke patients with mean age of 44.7 years and 50 % were male who treated consecutively as for first CS, and 50 age-and sex-matched healthy stroke-free controls. Using Speckle tracking TTE analysis we measured the global , passive and active longitudinal LA strain corresponding to the reservoir (LASRES), conduit(LASCD), and contractile function(LASCT),respectively in addition to standard other LA parameters and filling pressure parameters of Left ventricle(LV) in both group. Data were compared using t-test and Mann-Whitney test. Cryptogenic stroke patients as compared with controls had significantly reduced value of all components of LALS [Mean value of LASRES, LASCD and LASCT in CS group versus control group were 25.15±6.79 versus 43.95±4.62 (P-value &amp;lt;0.01), 14.41±3.53 versus 25.68±3.30 (P- value &amp;lt;0.01), 10.73±3.35 versus 18.28±1.60 (P-value &amp;lt;0.01) respectively] (Figure 1 and Figure 2). There were no significant differences in means of LA area and LA volume index in both groups (P value &amp;gt;0.05). Between parameters of LV filling pressures, it was noticed that early diastolic transmitral flow velocity (E) and early diastolic velocity at annulus (E’) were statistically lower in CS patients as compared to control group (P-value &amp;lt;0.01). In addition, the Cluster and Discriminant analysis used confirmed that LASRES, LASCD and LASCT were significantly lower in value in cryptogenic stroke patients in comparison to Control group which can be used to detect early LA dysfunction. Conclusion LA longitudinal strain in all components were significantly impaired in patients with CS. Measuring LALS parameters can be useful in determining early LA dysfunction in cryptogenic stroke patients.Figure 1-left atrial strain components.Figure 2 -left atrial strain component.

Effect of tafamidis on left atrial function in patients with transthyretin amyloid cardiomyopathy

Abstract Background Transthyretin amyloid cardiomyopathy (ATTR-CM) is characterized by the functional and structural consequences of amyloid infiltration predominantly within the ventricles, causing biventricular wall thickening. Amyloid infiltration can be observed in left atrium in ATTR-CM, however, the association of left atrial (LA) myocardial function with cardiovascular events and changes in LA myocardial function with tafamidis administration have not been elucidated. Purpose The aim of this study was to identify the association between baseline LA reservoir function evaluated by left atrial reservoir strain and cardiovascular events. Furthermore, monitoring the LA reservoir function before and after tafamidis administration, we also investigated the baseline factors associated with changes in LA reservoir function in patients with ATTR-CM. Methods We studied 55 patients with biopsy-proven ATTR-CM who were started on tafamidis in our institution between July 2019 and December 2022 (age: 76 ± 2 years, male: 93%). The primary endpoint was defined as hospitalization for heart failure or cardiovascular death during a median follow-up period of 28 ± 4 months after tafamidis administration. Furthermore, we assessed the factors associated with changes in LA function before and 25 ± 3 months after tafamidis administration for 49 patients who underwent sufficient follow-up echocardiography. Results During the follow-up period, 8 patients had cardiovascular death or cardiovascular hospitalization. The Kaplan-Meier curve indicated that the occurrence of cardiovascular events for patients with LA strain ≥ the median 8.6% was significantly lower than for those with LA strain &amp;lt; 8.6% (log-rank P =0.002; Figure A). Furthermore, comparing LA strain before and after tafamidis administration, the group with worsening LA strain tended to be older (79.0 ± 2.0 years vs. 73.6 ± 3.3 years, P=0.004), have higher brain natriuretic peptide (350 ± 83 pg/mL vs. 199 ± 47 pg/mL, P=0.003), have lower global longitudinal strain (GLS) (9.8 ± 1.4 % vs. 12.6 ± 1.6 pg/mL, P=0.008), and higher relative apical longitudinal strain index (1.63 ± 0.4 % vs. 1.14 ± 0.2 %, P=0.021). The multivariate logistic regression analysis was that age, GLS and relative apical longitudinal strain index were the independent determinants for deterioration of LA strain after tafamidis administration (Figure B). Conclusion In our study, baseline LA reservoir function was found to be closely associated with cardiovascular events after tafamidis administration, while age, GLS and relative apical longitudinal strain index were associated with worsening LA strain after tafamidis administration. Our findings could represent an additional parameter for the effective management of patients with ATTR-CM.Figure AFigure B

Association between left atrial dysfunction and adverse outcomes after tricuspid valve surgery for atrial functional tricuspid regurgitation

Abstract Objectives To identify factors associated with clinical outcomes in patients undergoing tricuspid valve (TV) surgery for atrial functional tricuspid regurgitation (AF- TR). Methods Among 1,670 patients who underwent TV surgery between January 2000 and December 2020, we included 83 AF-TR patients (69.1±9.2 years, 50 women) who had severe TR without any cause other than atrial fibrillation. A comprehensive analysis of right ventricular (RV) and left atrial (LA) function on preoperative and postoperative echocardiography was performed. LA function was evaluated by LA emptying fraction (LAEF), LA reservoir strain, and LA stiffness index. The primary outcome was a composite of all-cause death and heart failure hospitalization during follow up after surgery. Results For a median of 39.9 (interquartile range 19.9 to 55.8) months, the primary outcome occurred in 20 (24.1%) patients. Patients with a primary outcome showed significantly lower LAEF (9.7±7.3 vs. 21.8±6.7 %, p&amp;lt;0.001) and LA reservoir strain, and higher LA stiffness index than those without. However, there was no difference in RV chamber size and functional parameters according to the occurrence of a primary outcome. The restricted cubic spline plot exhibited a significant relationship between LAEF and primary outcome. The low baseline LAEF (&amp;lt;17%) group showed a poorer outcome than the high LAEF group (log rank p&amp;lt;0.001). In the Cox regression analysis, the low LAEF (&amp;lt;17%) was independent predictor for primary outcome (adjusted hazard ratio 13.5, 95% confidence interval 3.1–58.6). Conclusion In patients undergoing TV surgery with AF-TR, preoperative LA dysfunction was independently associated with adverse outcomes.Figure1

Characterization of left atrial function during cardiac (reverse) remodeling induced by pregnancy

Abstract Introduction The hemodynamic overload in pregnancy leads to cardiovascular remodeling, characterized by enlargement of left atrial (LA) and ventricular (LV) volumes associated with impaired LV relaxation, maintaining preserved systolic function. These changes are reversible during postpartum. Few scientific evidence has been published about LA function yet. Purpose To assess the changes in LA function through two-dimensional speckle tracking echocardiography analysis during pregnancy and its recovery up to 1 year after delivery and to determine potential predictors of its progression. Methods This prospective cohort study included volunteer pregnant women (healthy, obese and/or hypertensive and/or with gestational diabetes) recruited in two tertiary centers between 2019 and 2021. Women were evaluated by transthoracic echocardiography at the 1st trimester [1T, 10-15 weeks, baseline], 3rd trimester [3T, 30-35 weeks, peak of cardiac remodeling] of pregnancy as well as at the 1st, 6th and 12th month after delivery (during RR). Generalized linear mixed-effects models evaluated the extent of RR, including the variation of left atrial strain and its potential predictors. Results We included 130 pregnant women with a median age of 33 [30,36] years, 39,2% multiparas. Fifty-four (41.5%) were diagnosed with at least one cardiovascular risk factor. A significant enlargement of LA volume (24 [22, 28]mL/m2 to 29 [25, 33]mL/m2, p&amp;lt;0.001) associated with the increase of E/e’ (5.85 [5.08, 6.36] to 6.70 [5.67, 7.82], p&amp;lt;0.001) was observed from 1T to 3T, both recovering as soon as 1 month after delivery (LA volume: 29 [25, 33]mL/m2 to 24 [20, 27] mL/m2, p&amp;lt;0.001; E/e’: 6.70 [5.67, 7.82] to 5.70 [4.82, 6.47], p&amp;lt;0.001). Regarding LA function, a significant reduction of LA strain was verified from 1T to 3T (35 [31, 41]% to 31 [29, 36]%, p&amp;lt;0.001), recovering 6 months postpartum (31 [29, 36]% to 33 [30, 38]%, p=0.035). Systemic vascular resistance seemed to be an independent predictor of lower LA strain (-3.83 [-6.40, -1.25], p=0.004). The presence of cardiovascular risk factors (-0.80 [-2.28, 0.68], p=0.287), smoking habits (-1.26 [-2.82, 0.30], p=0.112), parity (-0.33 [-1.93, 1.27], p=0.684) and age (-0.11 [-0.29, 0.08], p=0.257) showed a non-significant impact in LA strain. Conclusion Despite the recovery in diastolic function and LA volume 1 month after delivery, the LA function only significantly improved 6 months later. Systemic vascular resistance was revealed as an independent predictor of LA strain.

Left atrial remodeling and novel biomarkers in obese patients with heart failure with preserved ejection fraction compared to type-2-diabetics and obese controls: a cardiac magnetic resonance study

Abstract Background Elevated filling pressures and subsequent left atrial (LA) dilation are common findings in heart failure with preserved ejection fraction (HFpEF), reflecting a chronic state of the disease and holding prognostic value. HFpEF is thought to develop through a long-term pro-inflammatory state triggered by comorbidities, such as obesity and type 2 diabetes mellitus (T2DM). Emerging biomarkers have shown associations with structural remodeling, but also increased myocardial stiffness. Purpose To elucidate the relationship between LA volume and function, and prognostic biomarkers (NT-proBNP, BNP-32, IL1R1, Galectin-3, and Pentraxin-3) in an obese cohort with T2DM or HFpEF and T2DM, versus healthy obese controls. Methods We conducted a prospective cohort study of 35 obese participants, divided into three groups: T2DM (n=16), HFpEF with T2DM (NYHA II-III, n=13), and healthy obese controls (n=6). Each subject underwent comprehensive CMR at a 3T scanner to assess LA strain and volume. Atrial strain was assessed on 2- and 4-chamber view cine images by experienced CMR investigators using dedicated software. Routine labs and serum levels of biomarkers were measured. If labs or images were repeated, the average was calculated. Statistical significance was determined through ANOVA and student’s t-test for group comparisons and Pearson correlation for associations between LA parameters and biomarker levels. Results Cohorts were evenly matched in terms of demographics, vital signs, and ventricular volumes and functions, as depicted in Table 1. Only one patient in the HFpEF subgroup reported history of atrial fibrillation. Both minimum and maximum LA volumes were significantly elevated in the HFpEF group compared to the T2DM and control groups (p &amp;lt; 0.018). LA strain (conduit, reservoir, and booster) was notably compromised in the HFpEF cohort, contrasting with the obese T2DM group where LA strain values did not differ significantly from those observed in obese controls (Figure 1). Biomarker analysis revealed a marked increase of NT-proBNP, BNP-32, Galectin-3, and Pentraxin-3 in the HFpEF cohort. In the HFpEF cohort, IL1R1 was the only biomarker that was strongly associated with higher left ventricular enddiastolic (r=0.69, p=0.003) and endsystolic volumes (r=0.75, p=0.009). Moreover, IL1R1 was the only biomarker associated with atrial functional changes (booster strain, r=-0.57, p=0.043) in the HFpEF patients. Our findings indicate that ILR1 plays a crucial role in the cardiometabolic (obesity-T2DM) HFpEF phenotype, with its activation leading to advanced cardiac remodeling. Conclusion Obese HFpEF patients with T2DM showed severely altered left atrial morphology and function compared to those that are only obese or obese with T2DM. Moreover, our findings revealed that atrial remodeling in this population is driven by pro-fibrotic inflammatory pathways.Characteristics of the study cohortLeft atrial strain analysis