BACKGROUND: Left atrial (LA) fibrosis is a marker of atrial cardiomyopathy and has been reported to be associated with both atrial fibrillation and ischemic stroke. Elucidating this relationship is clinically important as LA fibrosis could serve as a surrogate biomarker of LA cardiomyopathy. The objective of this study is to investigate the association of LA fibrosis and embolic stroke of undetermined source (ESUS) using cardiac magnetic resonance imaging.
RESULTS: Following an International Prospective Register of Systematic Reviews-registered protocol, 3 blinded reviewers performed a systematic review for studies that quantified the degree of LA fibrosis in patients with ESUS as compared with healthy patients from inception to February 2024. A meta-analysis was conducted in the mean difference. From 7 studies (705 patients), there was a significantly higher degree of LA fibrosis in patients with ESUS compared with healthy controls (MD, 5.71% [95% CI, 3.55%-7.87%], P<0.01). The degree of LA fibrosis was significantly higher in patients with atrial fibrillation than healthy controls (MD, 8.22% [95% CI, 5.62%-10.83%], P<0.01). A similar degree of LA fibrosis was observed in patients with ESUS compared with patients with atrial fibrillation (MD, -0.92% [95% CI, -2.29% to 0.44%], P=0.35).
CONCLUSIONS: A significantly higher degree of LA fibrosis was found in patients with ESUS as compared with healthy controls. This suggests that LA fibrosis may play a significant role in the pathogenesis of ESUS. Further research is warranted to investigate LA fibrosis as a surrogate biomarker of atrial cardiomyopathy and recurrent stroke risk in patients with ESUS.

OBJECTIVE: The influence of hypertensive disorders of pregnancy (HDP) on left atrial (LA) mechanics assessed by speckle tracking echocardiography (STE) has been poorly investigated. Accordingly, we performed a meta-analysis to summarize the main findings of STE studies who measured LA reservoir (LASr), conduit (LAScd) and contractile (LASct) strain in HDP women.
METHODS: All echocardiographic studies assessing LA strain parameters in HDP women vs. healthy controls, selected from PubMed and EMBASE databases, were included. The risk of bias was assessed by using the National Institutes of Health (NIH) Quality Assessment of Case-Control Studies. Continuous data (LASr, LAScd and LASct) were pooled as standardized mean difference (SMD) comparing HDP group with healthy controls. The overall SMDs of LASr, LAScd and LASct were calculated using the random-effect model.
RESULTS: The full-texts of 8 studies with 566 HDP women and 420 healthy pregnant women were analyzed. Average LASr (34.3 ± 6.4 vs 42.7 ± 5.3 %, P = 0.01) and LAScd (23.4 ± 6.3 vs 32.5 ± 6.0 %, P < 0.001) were significantly lower in HDP women than controls, whereas LASct (-13.0 ± 5.4 vs -13.7 ± 4.5 %, P = 0.18) was similar in the two groups of women. Substantial heterogeneity was detected among the studies evaluating LASr (I2 = 94.3 %), LAScd (I2 = 64.9 %) and LASct (I2 = 86.4 %). SMDs were large and statistically significant for LASr (-1.70, 95 %CI -2.34,-1.06, P < 0.001) and LAScd (-1.35, 95 %CI -1.69,-1.00, P < 0.001), small and not statistically significant for LASct (-0.11, 95 %CI -0.60,0.39, P = 0.678) assessment. Egger\'s test gave P-values of 0.10, 0.34 and 0.75 for LASr, LAScd and LASct measurement respectively, indicating no publication bias. On meta-regression analysis, none of the moderators was significantly associated with effect modification for LASr and its components (all P < 0.05).
CONCLUSIONS: HDPs are independently associated with LASr impairment in pregnancy. STE allows to identify, among HDP women, those who might benefit from a more aggressive antihypertensive treatment and/or a closer clinical follow-up, aimed at reducing the risk of adverse maternal outcome and cardiovascular complications later in life.

Left atrial (LA) strain imaging, which measures the deformation of the LA using speckle-tracing echocardiography (STE), has emerged recently as an exciting tool to help provide diagnostic and prognostic information for patients with a broad range of cardiovascular (CV) pathologies. Perhaps due to the LA\'s relatively thin-walled architecture compared with the more muscular structure of the left ventricle (LV), functional changes in the left atrium often precede changes in the LV, making LA strain (LAS) an earlier marker for underlying pathology than many conventional echocardiographic parameters. LAS imaging is typically divided into three phases according to the stage of the cardiac cycle: reservoir strain, which is characterized by LA filling during systole; conduit strain, which describes LA deformation during passive LV filling; and booster strain, which provides information on the LA atrium during LA systole in late ventricular diastole. While additional large-population studies are still needed to further solidify the role of LAS in routine clinical practice, this review will discuss the current evidence of its use in different pathologies and explore the possibilities of its applications in the future.

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BACKGROUND: There is no defined cause for cryptogenic stroke/embolic stroke of undetermined source (CS-ESUS). As atrial fibrillation (AF) develops in a significant proportion of these patients, it has been suggested that left atrial (LA) myopathy may predispose to CS-ESUS. We investigated alterations in echocardiographic measures of LA size and function in patients with CS-ESUS.
METHODS: A systematic literature review and meta-analysis was performed. PubMed, EMBASE, Cochrane Library, Web of Science and SCOPUS were searched for articles published between 1 January 1990 and 10 February 2023. All observational studies of adult CS-ESUS patients with LA volume or function measurements performed by transthoracic echocardiogram were included. Individual random effects meta-analyses were performed on LA measurements in the CS-ESUS patients using subgroup analysis of comparator groups.
RESULTS: We included 29 articles with 3927 CS-ESUS patients. Analysis of weighted mean differences showed CS-ESUS patients had altered LA structure and function parameters, with a larger maximum indexed LA volume, reduced LA emptying fraction and/or LA reservoir strain, compared to healthy controls and noncardioembolic stroke patients. Conversely, CS-ESUS patients had a smaller left atrium with better function, compared to cardioembolic stroke patients and CS-ESUS patients who subsequently developed atrial fibrillation.
CONCLUSIONS: LA volume and function are altered in CS-ESUS patients compared to healthy controls and other stroke aetiologies. An underlying atrial myopathy in a subset of CS-ESUS patients may be involved in both thrombogenesis and dysrhythmia (specifically AF). While LA functional assessment is not currently recommended following stroke, it may offer an opportunity for recurrent stroke risk stratification.

BACKGROUND: Left atrial (LA) appendage closure (LAAC) is effective in patients with atrial fibrillation who are not candidates for long-term anticoagulation. However, the impact of LAAC on LA function is unknown. The aim of this study is to evaluate the impact of LAAC on atrial function.
METHODS: This meta-analysis was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A search strategy was designed to utilize PubMed/Medline, EMBASE, and Google scholar for studies showing the effect of LAAC on the LA function from inception to November 20, 2021. The standardized mean difference (SMD) was calculated from the means and standard deviations.
RESULTS: Of 247 studies initially identified, 8 studies comprising 260 patients were included in the final analysis. There was a significant increase in LA emptying fraction following LAAC compared with preoperative function (SMD: 0.53; 95% confidence interval [CI]: 0.04-1.01; p = .03; I2  = 75%). In contrast, there were no significant differences in LA volume (SMD: -0.07; 95% CI: -0.82-0.69; p = .86; I2  = 92%) peak atrial longitudinal strain (SMD: 0.50; 95% CI: -0.08-1.08; p = .09; I2  = 89%), peak atrial contraction strain (SMD: 0.38; 95% CI: -0.22-0.99; p = .21; I2  = 81%), strain during atrial contraction (SMD: -0.24; 95% CI: -0.61-0.13; p = .20; I2  = 0%), strain during ventricular systole (SMD: 0.47; 95% CI: -0.32-1.27; p = .24; I2  = 89%), strain during ventricular diastole (SMD: 0.09; 95% CI: -0.32-0.51; p = .66; I2  = 65%).
CONCLUSIONS: LAAC is associated with improvement in the left atrial emptying fraction, but did not significantly influence other parameters.

Three-dimensional echocardiography can elucidate the phasic functions of the left atrium if a simultaneous acquisition of a pyramidal full-volume dataset, as gathered from the apical window and containing the entire left atrial and left ventricular cardiac sections, is obtained. Hence, conduit can be quantified as the integral of net, diastolic, instantaneous difference between synchronized atrial and ventricular volume curves, beginning at minimum ventricular cavity volume and ending just before atrial contraction. Increased conduit can reflect increased downstream suction, as conduit would track the apex-to-base intracavitary pressure gradient existing, in early diastole, within the single chamber formed by the atrium and the ventricle, when the mitral valve is open. Such a gradient increases in response to adrenergic stimulation or during exercise and mediates an increment in passive flow during early diastole, with the ventricle being filled from the atrial reservoir and, simultaneously, from blood drawn from the pulmonary veins. In this context conduit, and even more conduit flow rate, expressed in ml/sec, can be viewed as an indirect marker of left ventricular relaxation. It is well known, however, that a large amount of conduit (in relative terms) is also supposed to contribute to LV stroke volume in conditions of increased resistance to LV filling, when diastolic function significantly worsens. Stiffening of the atrio-ventricular complex implies increments in LA pressure more pronounced in late systole, causing markedly elevated \"v\" waves, independently of the presence of mitral insufficiency. The combination of increased atrio-ventricular stiffness and conduit flow is associated with an elevation of the right ventricular pulsatile relative to resistive load that negatively impacts on exercise capacity and survival in these patients. Atrial conduit is an \"intriguing\" parameter that conveys a noninvasive picture of the complex atrioventricular coupling condition in diastole and its backward effects on the right side of the heart and the pulmonary circulation. Given the easiness associated with its correctly performed quantification in the imaging laboratory, I am sure that conduit will survive the competitive access to the list of valuable parameters capable of deciphering, although not necessarily simplifying, the complex diastolic scenario in health and disease.

The aim of this systematic review and meta-analysis is to investigate the capacity of preinterventional left atrial strain (LAS) to predict AF recurrence (AFR) after catheter ablation by using all relative published data. Intervendor variability regarding different ultrasound stations and strain analysis software suites was taken into consideration. The research was performed according to PRISMA guidelines. The Cochrane database, MEDLINE, and EMBASE were searched for studies assessing echocardiography LAS prior to catheter ablation of AF cases. The systematic research yielded 10 studies (2 retrospective and 8 prospective, 880 patients in total). LAS differed significantly between the patients with AFR and those with no AF recurrence (nAFR) during the follow-up period (LASAFR: 17.5 ± 8.7% vs. LASnAFR: 24.1 ± 9.5%, p < 0.00001). A pooled cutoff value of 21.9% for LAS was extracted for the prediction of ablation success. Regarding intervendor variability, subgroup analyses were able to be performed for studies using GE and TomTec software. The difference in LASAFR and LASnAFR remained significant (p < 0.00001 and p < 0.0001 for TomTec and GE, respectively), while significant intervendor difference in absolute strain values was also detected (p < 0.0001 for both AFR and nAFR groups). LAS prior to catheter ablation is consistently lower in patients who experience AF recurrence. Its incorporation in clinical practice would assist physicians detect patients who require closer follow-up. Intervendor variability appears to be considerable and steps must be taken to document it thoroughly and mitigate it if possible.

The usefulness of peak atrial longitudinal strain (PALS) in identifying patients at high risk of atrial fibrillation (AF) recurrence after radiofrequency ablation (RFA) has been investigated in several small AF populations. The aim of this systematic review and meta-analysis was to investigate whether PALS predicts recurrence of AF after RFA treatment. MEDLINE, EMBASE and the Cochrane Library were searched. Studies investigating the value of PALS in predicting successful RFA in AF patients were selected. Patients underwent echocardiography prior to RFA. Risk of bias was evaluated using the Quality in Prognosis Studies (QUIPS) Tool. Twelve studies and a total of 1025 patients suffering from paroxysmal or persistent AF were included. Odds ratios (OR) were assessed in a random and fixed effects model for univariable and multivariable pooled analyses respectively. PALS was found to be a significant predictor of AF recurrence after RFA across study populations (Univariable: OR: 1.17, CI95% [1.03-1.34], p = 0.018, per 1% decrease) (Multivariable: OR: 1.16, CI95% [1.09-1.24], p < 0.001, per 1% decrease). Patients with recurrence had significantly lower PALS prior to RFA than patients who maintained sinus rhythm (15.7 ± 5.7% vs. 23.0 ± 7.0%, p = 0.016). A pooled analysis of weighted mean differences (WMD) also showed a significant difference in PALS between the two groups (WMD: - 6.57, CI95% [- 8.49: - 4.65], p < 0.001). Lower values of PALS are associated with an increased risk of AF recurrence after RFA. PALS provides prognostic value in clinical practice.

Percutaneous closure (LAAC) of the left atrial appendage (LAA) is an efficacious preventive procedure for patients with non-valvular atrial fibrillation (NVAF) and considerable bleeding risk. We sought to systematically review the available LAAC data on the novel occluder device LAmbre™.
For this systematic review, a search of the literature was conducted by 3 independent reviewers, reporting the safety and therapeutic success of LAAC in patients being treated with a LAmbre™. Publications reporting the safety and therapeutic success of LAAC using LAmbre™ in n > 5 patients were included.
The literature search retrieved n = 10 publications, encompassing n = 403 NVAF patients treated with a LAmbre™ LAAC, with relevant data regarding safety and therapeutic success of the procedure. The mean CHA2DS2-VASc Score was 4.0 + 0.9, and the mean HAS-BLED score was 3.4 + 0.5. The implantation success was 99.7%, with a mean procedure time of 45.4 ± 18.7 min, and a fluoroscopy time of 9.6 ± 5.9 min, and a contrast agent volume of 96.7 ± 0.7 ml. The anticoagulation regimen was switched to DAPT post procedure in the majority of the patients (96.8%). Partial and full recapture were done in 45.5% and in 25.6%, respectively. Major complications were reported in 2.9%, with 0.3% mortality, 1.7% pericardial tamponade, 0.3% stroke, and 0.6% major bleeding complications; no device embolization was observed. During follow up at 6 or 12 months, major adverse cardiovascular events were reported in 3.3%: Stroke or TIA in 1.7%, thrombus formation on the device in 0.7%, and residual flow > 5 mm in 1.0%. In some publications, the favorable implantion properties of the LAmbre™ for difficult anatomies such as shallow or multilobular LAA anatomies were described.
This systematic review on the LAmbre™ LAA-occluder including n = 403 NVAF patients demonstrates an excellent implantion success rate, promising follow-up clinical data, and favorable properties for also challenging LAA anatomies,. While its design seems to be helpful in preventing device embolization, pericardial tamponade may not be substantially reduced by the LAmbre™ as compared with other established LAAC devices. Further larger prospective multicenter registries and randomized trials are needed to scrutinize the value of the LAmbre™ compared with established LAAC devices.