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Abstract Background and objectives :The hypothesis of the study was the assumption that the serum levels of soluble ST2 (sST2) and growth differentiation factor (GDF-15) can be predictors of atrial fibrillation (AF) recurrence in long-term period after primary radiofrequency catheter ablation (RFA). Methods Of the 165 patients included in the prospective follow-up, the final analysis included 131 patients whose follow-up duration reached 18 months after the end of the blanking period (3 months after RFA). The median age of patients was 59.0 (50.0; 64.0) years, and 80 (61%) were men. Paroxysmal AF was present in 103 (79%) and persistent AF in 28 (21%) patients. All patients underwent transthoracic and transesophageal echocardiography, and electroanatomic mapping was used to assess the area of low-voltage zones (LVZ). sST2 and GDF-15 levels were determined by ELISA using GDF-15/MIC-1 analytical kits (BioVender, Czech Republic) and Presage ST2 (Critical Diagnostics, USA) before RFA. After RFA, patients had regular follow-up visits at 3-6-9-12-18 months with 12-lead ECG or Holter ECG monitoring and with clinical evaluation. The primary endpoint was the occurrence of the first symptomatic AF recurrence (AFr) lasting > 30 s, recorded on an ECG or during daily ECG monitoring, after a blanking period. Results At the 18-month follow-up, 47 patients (35.9%) had AFr. The groups with and without AFr didn`t differ in the LVZ area. The medians of NT-proBNP, GDF-15 and sST2 also didn`t differ significantly between the groups, but in patients with AFr, the proportion of those with sST2 ≥ 36 ng/ml (the border of the lower and middle terziles) was higher (p = 0.03). According to the one-factor Cox regression analysis, AFr were associated with four factors: AF history ≥ 1 year, early AFr (during the blanking period), left atrial appendage flow velocity (LAAFV)

Atrial fibrillation (AF), a common supraventricular arrhythmia, is associated with severe complications, including ischemic stroke and heart failure, significantly increasing morbidity and mortality rates. Its pathogenesis encompasses a wide array of electrophysiological and pathophysiological mechanisms. Central to AF’s onset, persistence, and recurrence is atrial structural remodeling, notably characterized by left atrial (LA) myocardial fibrosis, which acts as a crucial predictive indicator. Catheter ablation (CA) is the preferred treatment for symptomatic or drug-resistant AF, despite a notable recurrence rate post-procedure. Contemporary research highlights a significant link between LA fibrosis and AF recurrence following CA. Thus, precise evaluation and quantification of LA fibrosis are imperative for identifying AF patients at high risk, formulating individualized ablation approaches, and estimating the likelihood of post - CA AF recurrence. This paper thoroughly reviews the interconnected mechanisms between LA fibrosis and AF, encompassing aspects such as imaging and serological evaluations, with the aim of informing AF prevention and management strategies. [ABSTRACT FROM AUTHOR]

Background: Atrial fibrillation (AF) is the most common arrhythmia and is associated with considerable morbidity and mortality. Ischaemic heart failure (IHF) remains one of the most common causes of AF in clinical practice. However, ischaemia‐mediated mechanisms leading to AF are still incompletely understood, and thus, current treatment approaches are limited. To improve our understanding of the pathophysiology, we studied a porcine IHF model. Methods: In pigs, IHF was induced by balloon occlusion of the left anterior descending artery for 90 min. After 30 days of reperfusion, invasive haemodynamic measurements and electrophysiological studies were performed. Masson trichrome and immunofluorescence staining were conducted to assess interstitial fibrosis and myofibroblast activation in different heart regions. Results: After 30 days of reperfusion, heart failure with significantly reduced ejection fraction (left anterior obique 30°, 34.78 ± 3.29% [IHF] vs. 62.03 ± 2.36% [control], p <.001; anterior–posterior 0°, 29.16 ± 3.61% vs. 59.54 ± 1.09%, p <.01) was observed. These pigs showed a significantly higher susceptibility to AF (33.90% [IHF] vs. 12.98% [control], p <.05). Histological assessment revealed aggravated fibrosis in atrial appendages but not in atrial free walls in IHF pigs (11.13 ± 1.44% vs. 5.99 ±.86%, p <.01 [LAA], 8.28 ±.56% vs. 6.01 ±.35%, p <.01 [RAA]), which was paralleled by enhanced myofibroblast activation (12.09 ±.65% vs. 9.00 ±.94%, p <.05 [LAA], 14.37 ±.60% vs. 10.30 ± 1.41%, p <.05 [RAA]). Correlation analysis indicated that not fibrosis per se but its cross‐regional heterogeneous distribution across the left atrium was associated with AF susceptibility (r =.6344, p <.01). Conclusion: Our results suggest that left atrial cross‐regional fibrosis difference rather than overall fibrosis level is associated with IHF‐related AF susceptibility, presumably by establishing local conduction disturbances and heterogeneity. [ABSTRACT FROM AUTHOR]

Left atrial (LA) stiffness is one of the most important factors involved in LA remodeling. LA stiffness has rarely been studied postoperatively in patients with congenital heart diseases (CHDs). This study aimed to evaluate LA stiffness in CHD patients postoperatively. Seventy-five patients (CHDs, 67; controls, 8; age range, 10–41 years) who underwent cardiac catheterization at our institution were included in this study. From the pulmonary artery wedge pressure waveform obtained during cardiac catheterization, the pressure range between the v wave and x trough was determined, and this value was divided by the LA reservoir strain obtained by echocardiography to calculate LA stiffness, as previously reported. LA stiffness was significantly higher in postoperative CHD patients than in controls (0.28 ± 0.17 vs. 0.13 ± 0.03, p = 0.001). Nineteen of 52 (37%) patients in their teens, 8 of 11 (73%) patients in their 20 s, and 1 of 4 (25%) patients aged > 30 years had elevated LA stiffness values. In particular, all patients with an LA reservoir strain < 20% had elevated LA stiffness. In postoperative CHD patients, LA stiffness was frequently elevated from a young age. CHD patients with elevated LA stiffness should be cautious of possible LA dysfunction in the future. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF), the most frequently encountered arrhythmia worldwide, is associated with increased cardiovascular morbidity and mortality. Left atrial (LA) and antral region of the pulmonary veins (PVs) remodeling are risk factors for AF perpetuation. Among the methods of LA fibrosis quantification, bipolar voltage mapping during three-dimensional electro-anatomical mapping is less studied. The main aim of this study was to analyze the relationship between the degree of LA fibrosis quantified in low-voltage areas and the efficacy of AF radiofrequency catheter ablation. All consecutive patients with AF ablation were included, and the degree of LA fibrosis was measured based on the low-voltage areas in the LA and the antral region of PVs (<0.5 mV for patients in sinus rhythm and <0.25 mV for patients in AF at the time of the ablation procedure). The efficacy of AF ablation was determined by the rate of recurrence after a blanking period of three months. A total of 106 patients were included; from these, 38 (35.8%) had AF recurrence after RF ablation, while 68 (64.2%) were free of events. The area and percentage of LA fibrosis were significantly higher in the patients with AF recurrence (p = 0.018 and p = 0.019, respectively). However, no significant differences were found between the patients with and without AF recurrence in terms of the area and percentage of PVs fibrosis (p = 0.896 and p = 0.888, respectively). Moreover, LA fibrosis parameters proved to be excellent predictors for AF recurrence (areas under the curve of 0.834 and 0.832, respectively, p < 0.001) even after adjustment for LA indexed volume and CHA2DS2-VASc score. In conclusion, LA fibrosis measured on bipolar voltage maps increases the risk of AF recurrence after the RF catheter ablation procedure. [ABSTRACT FROM AUTHOR]

Background In patients with stiff left atrial (LA) syndrome, reservoir function is significantly impaired due to extensive LA fibrosis; consequently, the increase in LA pressure during haemodynamic stress is prominent, easily leading to pulmonary venous hypertension and subsequent pulmonary congestion, and eventually results in intractable heart failure. Case summary A 79-year-old female with mitral stenosis and atrial fibrillation underwent valve replacement, Cox-Maze IV procedure, LA plication, and appendage ligation 4 years prior to presentation. Thereafter, she underwent a total of two catheter ablation procedures for recurrent atrial tachycardia. Transthoracic echocardiography revealed two continuous colour jets across the interatrial septum, with a peak pressure gradient of 23 mmHg, which was consistent with the residual puncture hole at the catheter ablation procedures. Although transoesophageal echocardiography showed no evidence of prosthetic valve dysfunction, the pulmonary venous flow signal showed a significantly blunted systolic forward flow, extremely small retrograde reversal flow during atrial contraction, and prominent diastolic flow velocities, all of which indicated significantly impaired LA function. Cardiac catheter examination revealed a characteristic pulmonary capillary wedge pressure waveform, which consisted of a steep ascending limb of v wave with a large peak, consistent with stiff LA syndrome. Discussion Treatment of patients with stiff LA syndrome is quite challenging and restricted to the use of diuretics only, which has limited efficacy and eventually results in intractable heart failure. In this case, owing to the inter-atrial pressure–relieving gateway, the patient was only mildly symptomatic despite the existence of a non-compliant LA. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF), the most frequently encountered arrhythmia worldwide, is associated with increased cardiovascular morbidity and mortality. Left atrial (LA) and antral region of the pulmonary veins (PVs) remodeling are risk factors for AF perpetuation. Among the methods of LA fibrosis quantification, bipolar voltage mapping during three-dimensional electro-anatomical mapping is less studied. The main aim of this study was to analyze the relationship between the degree of LA fibrosis quantified in low-voltage areas and the efficacy of AF radiofrequency catheter ablation. All consecutive patients with AF ablation were included, and the degree of LA fibrosis was measured based on the low-voltage areas in the LA and the antral region of PVs (p = 0.018 and p = 0.019, respectively). However, no significant differences were found between the patients with and without AF recurrence in terms of the area and percentage of PVs fibrosis (p = 0.896 and p = 0.888, respectively). Moreover, LA fibrosis parameters proved to be excellent predictors for AF recurrence (areas under the curve of 0.834 and 0.832, respectively, p < 0.001) even after adjustment for LA indexed volume and CHA2DS2-VASc score. In conclusion, LA fibrosis measured on bipolar voltage maps increases the risk of AF recurrence after the RF catheter ablation procedure.

BackgroundPatients with mitral regurgitation (MR) commonly suffer from left atrial (LA) remodeling. LA fibrosis is considered to be a key player in the LA remodeling process, as observed in atrial fibrillation (AF) patients. Literature on the presence and extent of LA fibrosis in MR patients however, is scarce and its clinical implications remain unknown. Therefore, the ALIVE trial was designed to investigate the presence of LA remodeling including LA fibrosis in MR patients prior to and after mitral valve repair (MVR) surgery.MethodsThe ALIVE trial is a single center, prospective pilot study investigating LA fibrosis in patients suffering from MR in the absence of AF (identifier NCT05345730). In total, 20 participants will undergo a CMR scan including 3D late gadolinium enhancement (LGE) imaging 2 week prior to MVR surgery and at 3 months follow-up. The primary objective of the ALIVE trial is to assess the extent and geometric distribution of LA fibrosis in MR patients and to determine effects of MVR surgery on reversed atrial remodelling.ImplicationsThis study will provide novel insights into the pathophysiological mechanism of fibrotic and volumetric atrial (reversed) remodeling in MR patients undergoing MVR surgery. Our results may contribute to improved clinical decision making and patient-specific treatment strategies in patients suffering from MR.

Background: Epicardial adipose tissue (EAT) may induce left atrium (LA) wall inflammation and promote LA fibrosis. Therefore, simultaneous assessment of these two important atrial fibrillation (AF) risk factors would be desirable. Purpose To perform a comprehensive evaluation of 3D Dixon water–fat separated late gadolinium enhancement (LGE‐Dixon) MRI by analysis of repeatability and systematic comparison with reference methods for assessment of fibrosis and fat. Study Type: Prospective. Population: Twenty‐eight, 10, and 7 patients, respectively, with clinical indications for cardiac MRI. Field Strength/Sequence: A 1.5‐T scanner, inversion recovery multiecho spoiled gradient echo. Assessment Twenty‐eight patients (age 58 ± 19 years, 15 males) were scanned using LGE‐Dixon. A 5‐point Likert‐type scale was used to grade the image quality. Another 10 patients (age 46 ± 19 years, 9 males) were scanned using LGE‐Dixon and 3D proton density Dixon (PD‐Dixon). Finally, seven patients (age 62 ± 14 years, 4 males) were scanned using LGE‐Dixon and conventional LGE. The scan time, intraobserver and interobserver variability, and levels of agreement were assessed. Statistical Tests: Student's t‐test, one‐way ANOVA, and Mann–Whitney U‐test were used; P < 0.05 was considered significant, intraclass correlation coefficient (ICC). Results: The scan time (minutes:seconds) for LGE‐Dixon (n = 28) was 5:01 ± 1:40. ICC values for intraobserver and interobserver measurements of LA wall fibrosis percentage were 0.98 (95% CI, 0.97–0.99) and 0.97 (95% CI, 0.94–0.99) while of EAT were 0.92 (95% CI, 0.82–0.97) and 0.90 (95% CI, 0.80–0.95). The agreement for LA fibrosis percentage between the LGE‐Dixon and the conventional LGE was 0.92 (95% CI, 0.66–0.99) and for EAT volume between the LGE‐Dixon and the PD‐Dixon was 0.93 (95% CI, 0.72–0.98). Conclusion: LA fibrosis and EAT can be assessed simultaneously using LGE‐Dixon. This method allows a high level of intraobserver and interobserver repeatability as well as agreement with reference methods and can be performed in a clinically feasible scan time. Evidence Level 2 Technical Efficacy Stage: 3 [ABSTRACT FROM AUTHOR]

Background: Atrial fibrillation (AF) is a very common type of cardiac arrhythmia that threatens public health. Aging is an independent AF risk factor. However, the mechanism of age‐related AF remains unclear. Methods: A total of 36 Beagle dogs were selected and divided into three groups (12 in each group): two groups were 9‐year‐old aged dogs, and one group was 4‐year‐old adult dogs. Electrophysiological testing was employed to determine if modeling is successful. Patch‐clamp technique was employed to measure the If current. The expression of protein and mRNA related to If current were also tested. Collagen deposition was observed with the use of Masson staining. Results: Aging resulted in a higher collagen deposition percentage in the left atrium. The hyperpolarization‐activated cyclic nucleotide‐gated (HCN)2 and HCN4 expressions were increased in the atria and pulmonary veins but decreased in the sinus node of the aged group. Moreover, in the aged group, the left atrium mRNA expressions of Kcnd2 (Potassium voltage‐gated channel subfamily D member 2), Kcnh2, Kcnq1, Kcnj2, Kcnj11, and CACNA1H were significantly downregulated. The aged AF group also demonstrated sustained AF and significant changes in electrophysiological characteristics. The If current demonstrated an increased amplitude and was easier to activate in the aged AF group than in younger group. Finally, AF occurrence exacerbated aging‐induced cardiac fibrosis, thereby aggravating the above‐listed symptoms. Conclusion: With age, the increase in atrial fibrosis affected the expression of the ion channels, thereby modulating the If current. Moreover, AF also further exacerbated the degree of atrial fibrosis. [ABSTRACT FROM AUTHOR]

Abstract Background Atrial fibrillation (AF) is a very common type of cardiac arrhythmia that threatens public health. Aging is an independent AF risk factor. However, the mechanism of age‐related AF remains unclear. Methods A total of 36 Beagle dogs were selected and divided into three groups (12 in each group): two groups were 9‐year‐old aged dogs, and one group was 4‐year‐old adult dogs. Electrophysiological testing was employed to determine if modeling is successful. Patch‐clamp technique was employed to measure the If current. The expression of protein and mRNA related to If current were also tested. Collagen deposition was observed with the use of Masson staining. Results Aging resulted in a higher collagen deposition percentage in the left atrium. The hyperpolarization‐activated cyclic nucleotide‐gated (HCN)2 and HCN4 expressions were increased in the atria and pulmonary veins but decreased in the sinus node of the aged group. Moreover, in the aged group, the left atrium mRNA expressions of Kcnd2 (Potassium voltage‐gated channel subfamily D member 2), Kcnh2, Kcnq1, Kcnj2, Kcnj11, and CACNA1H were significantly downregulated. The aged AF group also demonstrated sustained AF and significant changes in electrophysiological characteristics. The If current demonstrated an increased amplitude and was easier to activate in the aged AF group than in younger group. Finally, AF occurrence exacerbated aging‐induced cardiac fibrosis, thereby aggravating the above‐listed symptoms. Conclusion With age, the increase in atrial fibrosis affected the expression of the ion channels, thereby modulating the If current. Moreover, AF also further exacerbated the degree of atrial fibrosis.

This systematic review and meta-analysis aims to clarify the role of pre-procedural cardiac magnetic resonance imaging (MRI) in identifying the association between left atrial (LA) characteristics and post-ablation atrial fibrillation (AF) recurrence. These characteristics include LA fibrosis, emptying function, sphericity, volume, volume index, peak strain and post-contrast T1 relaxation time. PubMed, EMBASE, and Cochrane were searched up to July 2020 for English language articles reporting the use of cardiac MRI in catheter ablation for AF. Studies reporting the prognostic value of pre-ablation cardiac MRI were included. All references and citations were filtered for relevant manuscripts. Twenty-four publications were identified. Every 10% increase in LA fibrosis was associated with a 1.54-fold increase in post-ablation AF recurrence (95%CI: 1.39–1.70, I2 = 50.1%). Every 10 ml increase in LA volume resulted in a hazard ratio of 1.07 (95%CI:1.03–1.12; I2 = 41.4%) for post-ablation AF recurrence. For LA sphericity, there was no significant association with post-ablation AF recurrence (HR: 1.032 [95%CI: 0.962–1.103, I2 = 49.6%). Egger's test was non-significant for publication bias in all meta-analyses. LA volume index, emptying function, peak strain and post-contrast LA T1 relaxation time had insufficient compatible publications to conduct a meta-analysis. LA fibrosis quantified by cardiac MRI is associated with risk of AF recurrence after AF ablation, while increased LA volume is associated with AF recurrence to a lesser extent. There remains insufficient evidence to support the routine measurement of LA sphericity, LA volume index, LA emptying function, peak strain and LA T1 relaxation time to predict AF recurrence after AF ablation. • A 10% increase in LA fibrosis leads to a 1.54-fold increase in post-ablation AF recurrence. • A 10 ml increase in LA volume leads to a 1.07 fold increase post-ablation AF recurrence. • There was no significant association between LA sphericity and post-ablation AF recurrence. • There's insufficient data to assess the effects of LA volume index, emptying function, peak strain or T1 relaxation time. [ABSTRACT FROM AUTHOR]

Background: Quantification of left atrial late gadolinium enhancement is a powerful clinical and research tool. Fibrosis burden has been shown to predict the success of pulmonary vein isolation, post-ablation reoccurrence, and major adverse cardiovascular events such as stroke. Overview: The standardized cardiovascular magnetic resonance imaging protocols 2020 update describes the key components of the examination. This review is a more in-depth guide, geared toward building left atrial late gadolinium enhancement imaging from the ground up. The standard protocol consists of the following: localization, pulmonary vein magnetic resonance angiography, cardiac cines, left ventricular, and atrial late gadolinium enhancement. We also review typical segmentation and post-processing techniques, as well as discuss pitfalls, limitations, and potential future innovations in this area. Conclusions: With sufficient experience and optimized protocols, left atrial late gadolinium enhancement imaging is a strong addition to the cardiac magnetic resonance imaging repertoire. [ABSTRACT FROM AUTHOR]

Aims: Atrial fibrillation (AF) and heart failure (HF) often coexist. Catheter ablation has been reported to restore left ventricular (LV) function but patients benefit differently. This study investigated the correlation between left atrial (LA) fibrosis extent and LV ejection fraction (LVEF) recovery after AF ablation.Methods and Results: In this study, 103 patients [64 years, 69% men, 79% persistent AF, LVEF 33% interquartile range (IQR) (25-38)] undergoing first time AF ablation were investigated. Identification of LA fibrosis and selection of ablation strategy were based on sinus rhythm voltage mapping. Continuous rhythm monitoring was used to assess ablation success. Improvement in post-ablation LVEF was measured as primary study endpoint. An absolute increase in post-ablation LVEF ≥10% was defined as 'Super Response'. Left atrial fibrosis was present in 38% of patients. After ablation LVEF increased by absolute 15% (IQR 6-25) (P < 0.001). Left ventricular ejection fraction improvement was higher in patients without LA fibrosis [15% (IQR 10-25) vs. 10% (IQR 0-20), P < 0.001]. An inverse correlation between LVEF improvement and the extent of LA fibrosis was found (R2 = 0.931). In multivariate analysis, the presence of LA fibrosis was the only independent predictor for failing LVEF improvement [odds ratio 7.2 (95% confidence interval 2.2-23.4), P < 0.001]. Echocardiographic 'Super Response' was observed in 55/64 (86%) patients without and 21/39 (54%) patients with LA fibrosis, respectively (P < 0.001).Conclusion: Presence and extent of LA fibrosis predict LVEF response in HF patients undergoing AF ablation. The assessment of LA fibrosis may impact prognostic stratification and clinical management in HF patients with AF. [ABSTRACT FROM AUTHOR]

Abstract Background High resolution 3D T1 mapping is important for assessment of diffuse myocardial fibrosis in left atrium or other thin-walled structures. In this work, we investigated a fast single-TI 3D high resolution T1 mapping method that directly transforms a 3D late gadolinium enhancement (LGE) volume to a 3D T1 map. Methods The proposed method, T1-refBlochi, is based on Bloch equation modeling of the LGE signal, a single-point calibration, and assumptions that proton density and T2* are relatively uniform in the heart. Several sources of error of this method were analyzed mathematically and with simulations. Imaging was performed in phantoms, eight swine and five patients, comparing T1-refBlochi to a standard spin-echo T1 mapping, 3D multi-TI T1 mapping, and 2D ShMOLLI, respectively. Results The method has a good accuracy and adequate precision, even considering various sources of error. In phantoms, over a range of protocols, heart-rates and T1 s, the bias ±1SD was -3 ms ± 9 ms. The porcine studies showed excellent agreement between T1-refBlochi and the multi-TI method (bias ±1SD = −6 ± 22 ms). The proton density and T2* weightings yielded ratios for scar/blood of 0.94 ± 0.01 and for myocardium/blood of 1.03 ± 0.02 in the eight swine, confirming that sufficient uniformity of proton density and T2* weightings exists among heterogeneous tissues of the heart. In the patients, the mean T1 bias ±1SD in myocardium and blood between T1-refBlochi and ShMOLLI was -9 ms ± 21 ms. Conclusion T1-refBlochi provides a fast single-TI high resolution 3D T1 map of the heart with good accuracy and adequate precision.

Hypertrophic cardiomyopathy (HCM) is associated with increased left ventricular (LV) mass, decreased myocardial strain, and the presence of LV fibrosis and scar. The relationship between LV scar and fibrosis with left atrial (LA) fibrosis in the setting of HCM has not been examined. The purpose of this study is to demonstrate a correlation between the degree of LA fibrosis and LV parameters in subjects with HCM. Twenty-eight subjects with HCM were imaged on a 1.5T MRI scanner with cine, LV and LA late gadolinium enhancement (LGE) sequences. LA LGE and LA measurements were correlated with LV measurements of volumes, mass, strain, and LGE. Other clinical conditions and medication usage were also examined and evaluated for correlation with LA and LV parameters. LV LGE was identified in 24 (86%) of the cases and LA LGE was identified in all of the cases. Extent of LA fibrosis significantly correlated with percent LV LGE (r = 0.64, p = 0.001), but not with indexed LV mass or maximum wall thickness. Extent of LA fibrosis also moderately correlated with decreased LV global strain (radial, r = - 0.50, p = 0.013; circumferential, r = 0.47, p = 0.02; longitudinal, r = 0.52, p = 0.013). Increased LA systolic volume correlated moderately with LV end diastolic volume (r = 0.50, p = 0.006). Patients on therapy with Renin-Angiotensin-Aldosterone System (RAAS) Inhibition had significantly less LA LGE compared to those without (18.6% vs 10.8%, p = 0.023). LA fibrosis, as measured by LGE, is prevalent in HCM and is correlated with LV LGE. The correlation between LA and LV LGE might suggest either that LA fibrosis is a consequence of LV remodeling, or that LA and LV fibrosis are both manifestations of the same cardiomyopathic process. Further study is warranted to determine the causality of LA scar in this population. [ABSTRACT FROM AUTHOR]

Defining left atrial (LA) function has recently emerged as a powerful parameter, particularly in evaluation of left ventricular (LV) diastolic dysfunction (LVDD) and heart failure with preserved ejection fraction. Echocardiographic assessment of LVDD by echocardiography remains a challenging task; recent recommendations provide a simpler approach than previous. However, the shortcomings of the proposed approach (including transmitral flow, tissue velocity, maximum left atrial volume [LAV], and estimated pulmonary artery systolic pressure), lead to the presence and severity of LVDD remaining undetermined in a significant proportion of patients. Maximum LAV is a surrogate measure of the chronicity and severity of LVDD, but LAV alone is an insensitive biomarker of early phases of LVDD, because the LA may take time to remodel. Because the primary function of the LA is to modulate LV filling, it is not surprising that functional LA changes become evident at the earliest stages of LVDD. Moreover, LA function may provide additive value, not only in diagnosing LVDD, but also in grading its severity and in monitoring the effects of treatment. The current review provides a critical appraisal on the existing evidence for the role of LA metrics in evaluation of LVDD and consequent heart failure with preserved ejection fraction. [ABSTRACT FROM AUTHOR]

Background: Ablation-induced left atrial (LA) edema may result in procedural failure due to reversible pulmonary vein isolation. Conventional T2-weighted magnetic resonance edema imaging is limited by low spatial resolution.Objective: The purpose of this pilot study was to optimize and validate a 3-dimensional (3D) sampling perfection with application-optimized contrasts using different flip-angle evolution (SPACE) sequence for quantification of T2 signal in the LA, and to apply it in recently ablated patients, comparing myocardial edema on T2-SPACE to tissue damage on late gadolinium enhancement (LGE) imaging.Methods: Phantom studies were performed to identify 3D-SPACE parameters for optimal contrast between normal and edematous myocardium. Fourteen AF patients were imaged with both 3D-SPACE and dark-blood turbo-spin echo (DB-TSE) to compare image quality and signal intensity between the 2 techniques. Eight patients underwent pre- and postablation 3D-SPACE and 3D-LGE imaging. Ablation points were co-registered with corresponding myocardial sectors, and ablation-induced changes in T2 and LGE signal intensities were measured.Results: Signal-to-noise ratio and contrast-to-noise ratio were higher on SPACE vs DB-TSE (65.5 ± 33.9 vs 35.7 ± 17.9; P = .01; and 59.4 ± 33.0 vs 32.9 ± 17.7; P = .04, respectively). T2-signal correlated well on 3D-SPACE and DB-TSE, such that each unit increase in TSE intensity correlated with a 0.69-unit increase in SPACE intensity (95% confidence interval 0.56-0.82; P <.001). T2 and LGE signal intensities were acutely increased at ablation sites. The extent of postablation edema was higher compared to LGE, although the spatial distribution of hyperenhancement around pulmonary veins seemed similar in both modalities.Conclusion: T2-SPACE can be used to map the extent of acute postablation edema in the thin LA myocardium, with improved resolution and lower artifact compared to traditional DB-TSE. [ABSTRACT FROM AUTHOR]

Background: Patients with mitral regurgitation (MR) commonly suffer from left atrial (LA) remodeling. LA fibrosis is considered to be a key player in the LA remodeling process, as observed in atrial fibrillation (AF) patients. Literature on the presence and extent of LA fibrosis in MR patients however, is scarce and its clinical implications remain unknown. Therefore, the ALIVE trial was designed to investigate the presence of LA remodeling including LA fibrosis in MR patients prior to and after mitral valve repair (MVR) surgery., Methods: The ALIVE trial is a single center, prospective pilot study investigating LA fibrosis in patients suffering from MR in the absence of AF (identifier NCT05345730). In total, 20 participants will undergo a CMR scan including 3D late gadolinium enhancement (LGE) imaging 2 week prior to MVR surgery and at 3 months follow-up. The primary objective of the ALIVE trial is to assess the extent and geometric distribution of LA fibrosis in MR patients and to determine effects of MVR surgery on reversed atrial remodelling., Implications: This study will provide novel insights into the pathophysiological mechanism of fibrotic and volumetric atrial (reversed) remodeling in MR patients undergoing MVR surgery. Our results may contribute to improved clinical decision making and patient-specific treatment strategies in patients suffering from MR., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 el Mathari, Kluin, Hopman, Bhagirath, Oudeman, Vonk, Nederveen, Eberl, Klautz, Chamuleau, van Ooij and Götte.)

Background: Prognostic significance of left atrial (LA) function in patients with atrial fibrillation (AF) is poorly defined.Objective: To examine the association of LA function measured with cardiac magnetic resonance (CMR) feature-tracking and AF recurrence following catheter ablation.Methods: One hundred and twenty-one AF patients (72% paroxysmal, mean age 59 ± 10 years) were enrolled. Baseline LA function was measured by calculating passive, active, and total emptying fractions (LAEF) and analysis of global longitudinal strain and strain rates. Patients were followed up for recurrence of AF or atrial tachycardia (AT). Hazard ratios for recurrence were calculated using Cox proportional models adjusted for potential clinical confounders, type of AF, left ventricular ejection fraction, AF duration, LA volume, and late gadolinium enhancement (LGE).Results: During a mean follow-up of 18 ± 9 months, 52 patients (43%) experienced recurrent AF/AT. Patients with recurrent AF/AT had higher baseline LA volume index and lower LA passive, and total LAEF (P < .05 for all). The baseline peak LA strain and strain rates in all phases of LA function were lower in the AF/AT recurrence group (P < .01 for all). In multivariable analysis total LAEF, peak LA strain, and systolic and late diastolic strain rates were associated with recurrence. Both peak LA strain and total LAEF improved prediction of recurrent AT/AF compared to the baseline clinical model, including LA LGE (C statistic 0.82 vs 0.77, P < .05 for both total LAEF and peak LA strain).Conclusions: LA reservoir function was independently associated with recurrent AF/AT after PVI and can additionally improve risk stratification in patients undergoing PVI. [ABSTRACT FROM AUTHOR]

Background: Cardiac magnetic resonance (CMR) T1 mapping is an emerging tool for objective quantification of myocardial fibrosis. Objectives: To (a) establish the feasibility of left atrial (LA) T1 measurements, (b) determine the range of LA T1 values in patients with atrial fibrillation (AF) vs healthy volunteers, and (c) validate T1 mapping vs LA intracardiac electrogram voltage amplitude measures. Methods: CMR imaging at 1.5 T was performed in 51 consecutive patients before AF ablation and in 16 healthy volunteers. T1 measurements were obtained from the posterior LA myocardium by using the modified Look-Locker inversion-recovery sequence. Given the established association of reduced electrogram amplitude with fibrosis, intracardiac point-by-point bipolar LA voltage measures were recorded for the validation of T1 measurements. Results: The median LA T1 relaxation time was shorter in patients with AF (387 [interquartile range 364–428] ms) compared to healthy volunteers (459 [interquartile range 418–532] ms; P < .001) and was shorter in patients with AF with prior ablation compared to patients without prior ablation (P = .035). In a generalized estimating equations model, adjusting for data clusters per participant, age, rhythm during CMR, prior ablation, AF type, hypertension, and diabetes, each 100-ms increase in T1 relaxation time was associated with 0.1 mV increase in intracardiac bipolar LA voltage (P = .025). Conclusions: Measurement of the LA myocardium T1 relaxation time is feasible and strongly associated with invasive voltage measures. This methodology may improve the quantification of fibrotic changes in thin-walled myocardial tissues. [Copyright &y& Elsevier]

Background: Atrial fibrillation (AF) is a very common type of cardiac arrhythmia that threatens public health. Aging is an independent AF risk factor. However, the mechanism of age-related AF remains unclear., Methods: A total of 36 Beagle dogs were selected and divided into three groups (12 in each group): two groups were 9-year-old aged dogs, and one group was 4-year-old adult dogs. Electrophysiological testing was employed to determine if modeling is successful. Patch-clamp technique was employed to measure the I f current. The expression of protein and mRNA related to I f current were also tested. Collagen deposition was observed with the use of Masson staining., Results: Aging resulted in a higher collagen deposition percentage in the left atrium. The hyperpolarization-activated cyclic nucleotide-gated (HCN)2 and HCN4 expressions were increased in the atria and pulmonary veins but decreased in the sinus node of the aged group. Moreover, in the aged group, the left atrium mRNA expressions of Kcnd2 (Potassium voltage-gated channel subfamily D member 2), Kcnh2, Kcnq1, Kcnj2, Kcnj11, and CACNA1H were significantly downregulated. The aged AF group also demonstrated sustained AF and significant changes in electrophysiological characteristics. The I f current demonstrated an increased amplitude and was easier to activate in the aged AF group than in younger group. Finally, AF occurrence exacerbated aging-induced cardiac fibrosis, thereby aggravating the above-listed symptoms., Conclusion: With age, the increase in atrial fibrosis affected the expression of the ion channels, thereby modulating the I f current. Moreover, AF also further exacerbated the degree of atrial fibrosis., (© 2022 The Authors. Annals of Noninvasive Electrocardiology published by Wiley Periodicals LLC.)

In patients with atrial fibrillation (AF), extensive atrial tissue fibrosis identified by delayed enhancement magnetic resonance imaging has been associated with early recurrence of AF after catheter ablation. We present a case of a patient with extensive atrial fibrosis and AF recurrence.The study of late gadolinium enhancement with cardiac magnetic resonance imaging in patients with AF could be a valuable noninvasive tool for the selection of patients suitable for successful catheter ablation. [ABSTRACT FROM AUTHOR]

Background: Left atrial (LA) arrhythmogenic substrate beyond the pulmonary veins (PV) seems to play a crucial role in the maintenance of atrial fibrillation (AF). The aim of this study was to evaluate the association of selected parameters with the presence and extent of voltage-defined LA fibrosis in patients with long-standing persistent AF (LSPAF) undergoing catheter ablation., Methods: One hundred and sixteen consecutive patients underwent high density-high resolution voltage mapping of the LA with a multielectrode catheter following PV isolation and restoration of sinus rhythm with cardioversion. A non-invasive dataset, such as clinical variables, two-and three-dimensional echocardiography determined LA size and function and fibrillatory-wave amplitude on a standard surface electrocardiogram were obtained during AF before ablation., Results: Low-voltage areas (LVA; 15 cm² [IQR 8-31]) were detected in 56% of patients. Twenty nine percent of them presented mild, 43% moderate and 28% severe global LVA burden. In univariate analysis, age ≥ 57 years old, female sex, body surface area ≤ 1.76 m², valvular heart disease, moderate mitral regurgitation, chronic coronary syndrome, hypothyroidism, CHA₂DS₂-VASc score ≥ 3 and ≥ 4 predicted the presence of LVA. In multivariate analysis only female sex, valvular heart disease and CHA₂DS₂-VASc ≥ 4 remained statistically significant. AF duration, LA size and function and fibrillatory-waves amplitude were neither associated with the prediction of the LVA, nor severe LVA burden., Conclusions: A LSPAF diagnosis does not indicate the presence of voltage defined fibrosis in many cases. Simple non-invasive screening of the LSPAF population could predict LVA prevalence.

Aims: Atrial fibrillation (AF) and heart failure (HF) often coexist. Catheter ablation has been reported to restore left ventricular (LV) function but patients benefit differently. This study investigated the correlation between left atrial (LA) fibrosis extent and LV ejection fraction (LVEF) recovery after AF ablation., Methods and Results: In this study, 103 patients [64 years, 69% men, 79% persistent AF, LVEF 33% interquartile range (IQR) (25-38)] undergoing first time AF ablation were investigated. Identification of LA fibrosis and selection of ablation strategy were based on sinus rhythm voltage mapping. Continuous rhythm monitoring was used to assess ablation success. Improvement in post-ablation LVEF was measured as primary study endpoint. An absolute increase in post-ablation LVEF ≥10% was defined as 'Super Response'. Left atrial fibrosis was present in 38% of patients. After ablation LVEF increased by absolute 15% (IQR 6-25) (P < 0.001). Left ventricular ejection fraction improvement was higher in patients without LA fibrosis [15% (IQR 10-25) vs. 10% (IQR 0-20), P < 0.001]. An inverse correlation between LVEF improvement and the extent of LA fibrosis was found (R2 = 0.931). In multivariate analysis, the presence of LA fibrosis was the only independent predictor for failing LVEF improvement [odds ratio 7.2 (95% confidence interval 2.2-23.4), P < 0.001]. Echocardiographic 'Super Response' was observed in 55/64 (86%) patients without and 21/39 (54%) patients with LA fibrosis, respectively (P < 0.001)., Conclusion: Presence and extent of LA fibrosis predict LVEF response in HF patients undergoing AF ablation. The assessment of LA fibrosis may impact prognostic stratification and clinical management in HF patients with AF., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Background: in the recent years, there has been an increasing number of publications postulating that data on left atrial (LA) structure obtained by late gadolinium enhancement magnetic resonance imaging (LGE MRI) can improve the management of patients with atrial fibrillation (AF). At the same time, similar data regarding healthy LA myocardium is limited., Aim: to assess structural and functional properties of LA in healthy volunteers (HV) using cardiac magnetic resonance (CMR) (including LGE MRI); to compare these properties in patients with AF and HV., Materials and Methods: We included in this study 53 patients with AF (28 without signs of cardiovascular disease, 28 with hypertension) and 23 HV of similar age. All enrolled persons underwent MRI. Cine-MRI was used to assess end diastolic volume of LA (LA EDV), LA ejection fraction (LA EF), left ventricular diastolic index (LV DI). High resolution LGE MRI was performed 15-20 min after gadoversetamide injection using IR 3D gradient echo pulse sequence with fat saturation (TI 290-340 ms, TE 2.44 ms, TR 610-1100ms). On obtained images LA was segmented semiautomatically. LA fibrosis quantification was performed using developed software LGE Heart Analyzer. The extent of fibrosis was represented as percent of LA myocardium volume. Fibrosis location was determined on reconstructed rotating 3D LA model., Results: Compared with patients HV had lower LA EDV (59 [54; 78] ml and 79 [65.5; 86.6] ml, р=0.043, respectively), higher LA EF (56.1 [49; 63.2] % and 44.5 [34.5, 54.5] %, р=0.03, respectively), and lower extent of LA fibrosis (0.7 [0.05; 3.5] % and 9.1 [1.7; 18] %, р.

Background: High resolution 3D T1 mapping is important for assessment of diffuse myocardial fibrosis in left atrium or other thin-walled structures. In this work, we investigated a fast single-TI 3D high resolution T1 mapping method that directly transforms a 3D late gadolinium enhancement (LGE) volume to a 3D T1 map., Methods: The proposed method, T1-refBlochi, is based on Bloch equation modeling of the LGE signal, a single-point calibration, and assumptions that proton density and T2* are relatively uniform in the heart. Several sources of error of this method were analyzed mathematically and with simulations. Imaging was performed in phantoms, eight swine and five patients, comparing T1-refBlochi to a standard spin-echo T1 mapping, 3D multi-TI T1 mapping, and 2D ShMOLLI, respectively., Results: The method has a good accuracy and adequate precision, even considering various sources of error. In phantoms, over a range of protocols, heart-rates and T1 s, the bias ±1SD was -3 ms ± 9 ms. The porcine studies showed excellent agreement between T1-refBlochi and the multi-TI method (bias ±1SD = -6 ± 22 ms). The proton density and T2* weightings yielded ratios for scar/blood of 0.94 ± 0.01 and for myocardium/blood of 1.03 ± 0.02 in the eight swine, confirming that sufficient uniformity of proton density and T2* weightings exists among heterogeneous tissues of the heart. In the patients, the mean T1 bias ±1SD in myocardium and blood between T1-refBlochi and ShMOLLI was -9 ms ± 21 ms., Conclusion: T1-refBlochi provides a fast single-TI high resolution 3D T1 map of the heart with good accuracy and adequate precision.