Left atrial strain predicts recurrence of atrial arrhythmias after catheter ablation of persistent atrial fibrillation

Atrial Mechanics, Atrial Cardiomyopathy and Impact of Atrial Interventions

Our comprehension of atrial mechanics, atrial cardiomyopathy and their clinical implications across various cardiovascular conditions has advanced significantly. Atrial interventions can have differing effects on atrial mechanics. With the rapid increase in the use of atrial interventions, it is crucial for investigators and clinicians to acknowledge the potential adverse effects of these interventions on atrial mechanics that might not be clinically significant at the time of interventions. Recognizing the preclinical stage of atrial maladaptation might enable early interventions before the development of irreversible atrial remodeling and clinical manifestation. We review normal atrial function and mechanics, and atrial cardiomyopathy in select cardiovascular conditions. We also summarize and discuss the current evidence of the impact of various atrial interventions on atrial function and mechanics.

Potential Role of Left Atrial Strain to Predict Atrial Fibrillation Recurrence after Catheter Ablation Therapy: A Clinical and Systematic Review

Pulmonary vein isolation (PVI) with catheter ablation (CA) represents an effective therapy for atrial fibrillation (AF). Unfortunately, it is still not exempt from severe complications. The balance of risks and benefits should be assessed, and a patient-tailored approach is desirable. So far, several clinical and cardiac imaging parameters have been evaluated to investigate pre- and post-procedural features that could help clinicians in the selection of patients at high risk of a poor outcome after CA. This clinical and systematic review analyses the potential role of new LA parameters, such as LA reservoir strain, to predict AF recurrence after CA therapy. Notably, LA reservoir strain gains substantial clinical importance in patients with paroxysmal AF and when a low CHADS2-VASc score is retrieved. LA reservoir strain provides data concerning the risk of AF recurrence after PVI and, thus, in the management of long-term medical therapy in this patient's group.

Evaluation of left atrial strain imaging and integrated backscatter as predictors of recurrence in patients with paroxysmal, persistent, and long-standing persistent atrial fibrillation undergoing catheter ablation

BACKGROUND

Impaired left atrial (LA) strain predicts atrial fibrillation (AF) recurrence after catheter ablation (CA), but currently there is no cut-off to guide patient selection for CA. Integrated backscatter (IBS) is a promising tool for noninvasive quantification of myocardial fibrosis. The aim of this study was to compare LA strain and IBS between paroxysmal, persistent, and long-standing persistent AF and evaluate their association with AF recurrence after CA.

METHODS

Analysis of consecutive patients with symptomatic paroxysmal and persistent AF who underwent CA. LA phasic strain, strain rate and IBS were assessed by two-dimensional speckle-tracking at baseline.

RESULTS

We analyzed 78 patients, 31% with persistent AF (46% long-standing AF), 65% male, mean age 59 ± 14 years, who underwent CA and were followed-up for 12 months. AF recurrence occurred in 22 (28%) patients. LA phasic strain parameters were significantly impaired in patients with AF recurrence and were independent predictors of AF recurrence in a multivariable analysis. LA reservoir strain (LASr) < 18% predicted AF recurrence with 86% sensitivity and 71% specificity, with a higher predictive power compared to LA volume index (LAVI). LASr < 22% in paroxysmal AF and LASr < 12% in persistent AF correlated with AF recurrence. Increased IBS was a predictor of AF recurrence in patients with paroxysmal AF.

CONCLUSION

LA phasic strain parameters were predictors of AF recurrence after CA, independently of LAVI and AF subtype. LASr < 18% showed a higher predictive power compared to LAVI. Further studies are needed to investigate the role of IBS as a predictor of AF recurrence.

Study on the relationship between atrial high-rate episode and left atrial strain in patients with cardiac implantable electronic device

Background

Although atrial high-rate episode (AHRE) and atrial fibrillation (AF) cannot entirely be identical, recent studies suggest AHRE is linked to AF development and shares some characteristics with AF regarding thromboembolism. At present, there is still lack of predictive indicators for AHRE and diagnostic methods and clinical indicators for AHRE in patients without cardiac implantable electronic device (CIED). The aim of this study was thus to explore the relationship between AHRE and left atrial (LA) strain parameters with the goal of identifying high-risk populations of AHRE by LA strain characteristics.

Methods

From February 2022 to May 2023, a total of 105 CIED patients were enrolled and divided into two groups based on whether AHRE had occurred: AHRE (-) group (n=65) and AHRE (+) group (n=40). Real-time three-dimensional echocardiography (RT-3DE) technique was used to obtain the LA time-volume curve. The collected dynamic images were analyzed on the Echopac 204 workstation to obtain the parameters of LA. The four-dimensional automatic LA quantitative analysis (4D Auto LAQ) technology was used to analyze the LA strain parameters: LA reservoir longitudinal strain (LASr), LA conduit longitudinal strain (LAScd), LA contraction longitudinal strain (LASct), LA reservoir circumferential strain (LASr-c), LA conduit circumferential strain (LAScd-c), LA contraction circumferential strain (LASct-c). Correlation analysis was carried out using Binary logistic regression analysis. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the diagnostic performance of LASct in AHRE.

Results

Body surface area (BSA) [odds ratio (OR) =8.34, 95% confidence interval (CI): 1.32-72.30, P=0.037], LASct (OR =1.20, 95% CI: 1.05-1.39, P=0.013) and LA end-systolic volume (LAESV) (OR =1.02, 95% CI: 1.00-1.04, P=0.023) were the influencing factors of AHRE. Only LASct (OR =1.18, 95% CI: 1.01-1.38, P=0.041) was found to be an independent influencing factor of AHRE. This result remained significant after adjusting for age, sex, hypertension, diabetes, and stroke history. The ROC curve showed that the cut-off for predicting AHRE was LASct =-4.125% with sensitivity of 37.5% and specificity of 87.7%.

Conclusions

This cross-sectional study found that decreased LASct (absolute value) is an independent risk factor for the AHRE and has diagnostic efficacy in certain degree for the occurrence of AHRE.

Determinants and prognostic implications of left atrial reverse remodelling after coarctation of aorta repair in adults

AIMS

Left atrial (LA) dysfunction and atrial fibrillation are also relatively common in adults with coarctation of aorta (COA), and the severity of LA dysfunction is associated with a higher risk of atrial fibrillation in this population. The purpose of this study was to determine whether LA function improved after COA repair (LA reverse remodelling), and the relationship between LA reverse remodelling and atrial fibrillation.

METHODS AND RESULTS

Retrospective cohort study of adults undergoing COA repair (2003-20). LA reservoir strain was assessed pre intervention and 12-24 months post intervention, using speckle tracking echocardiography. Incident atrial fibrillation was assessed from COA repair to last follow-up. Of 261 adults who underwent COA repair [age 37 ± 13 years; males 148 (57%)], 124 (47%) and 137 (53%) presented with native vs. recurrent COA, respectively. Of 261 patients, 231 (82%) and 48 (18%) underwent surgical and transcatheter COA repair, respectively. The LA reservoir strain increased from 32 ± 8% (pre intervention) to 39 ± 7% (post intervention), yielding a relative increase of 21 ± 5%. Older age [β ± standard error (SE) -0.16 ± 0.09 per 5 years, P = 0.02], higher systolic blood pressure (β ± SE -0.12 ± 0.04 per 5 mmHg, P = 0.005), and higher residual COA mean gradient (β ± SE -0.17 ± 0.06 per 5 mmHg, P = 0.002) post intervention were associated with less LA reverse remodelling, after adjustment for sex, hypertension diagnosis, and left ventricular indices. LA reverse remodelling (hazard ratio 0.97, 95% confidence interval 0.96-0.98 per 1% increase from pre-intervention LA function, P = 0.006) was associated with a lower risk of atrial fibrillation after adjustment for age, sex, pre-intervention LA reservoir strain, and history of atrial fibrillation.

CONCLUSION

COA repair resulted in improved LA function and decreased risk for atrial fibrillation, especially in patients without residual hypertension or significant residual COA gradient.

Left Atrial Low-Voltage Areas Predict the Risk of Atrial Fibrillation Recurrence after Radiofrequency Ablation

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.

Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.

Personalized biomechanical insights in atrial fibrillation: opportunities & challenges

INTRODUCTION

Atrial fibrillation (AF) is an increasingly prevalent and significant worldwide health problem. Manifested as an irregular atrial electrophysiological activation, it is associated with many serious health complications. AF affects the biomechanical function of the heart as contraction follows the electrical activation, subsequently leading to reduced blood flow. The underlying mechanisms behind AF are not fully understood, but it is known that AF is highly correlated with the presence of atrial fibrosis, and with a manifold increase in risk of stroke.

AREAS COVERED

In this review, we focus on biomechanical aspects in atrial fibrillation, current and emerging use of clinical images, and personalized computational models. We also discuss how these can be used to provide patient-specific care.

EXPERT OPINION

Understanding the connection betweenatrial fibrillation and atrial remodeling might lead to valuable understanding of stroke and heart failure pathophysiology. Established and emerging imaging modalities can bring us closer to this understanding, especially with continued advancements in processing accuracy, reproducibility, and clinical relevance of the associated technologies. Computational models of cardiac electromechanics can be used to glean additional insights on the roles of AF and remodeling in heart function.

Value of Left Atrial Strain in Predicting Recurrence after Atrial Fibrillation Ablation

This study tested the relationship between left atrial (LA) function parameters and the results of pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Consecutive patients undergoing PVI for the first time between 2019 and 2021 were included. Patients underwent radiofrequency ablation using contact force catheters and an electroanatomical system. Follow-up consisted of ambulatory visits/televisits and 7-day Holter monitoring (at 6 and 12 months after ablation). On the day of ablation, all patients underwent transesophageal and transthoracic echocardiography with LA strain analysis. The primary endpoint was atrial tachyarrhythmia recurrence during the follow-up period. Of 221 patients, 22 did not meet the echocardiographic quality criteria, leaving 199 patients. The median follow-up period was 12 months, and 12 patients were lost to follow-up. Recurrences were observed in 67 patients (35.8%) after a mean of 1.06 procedures per patient. The patients were divided into a sinus rhythm (SR, n = 109) group and an AF (n = 90) group based on their cardiac rhythm at the time of echocardiography. In the SR group, univariable analysis showed that LA reservoir strain, LA appendage emptying velocity (LAAV), and LA volume index predicted AF recurrence, with only LAAV being significant in the multivariable analysis. In AF patients, univariable analysis revealed no LA strain parameters predicting AF recurrence.

Speckle tracking echocardiography in early disease stages: a therapy modifier?

Echocardiography has been included as a first-line tool in several international guidelines for the management of patients with various cardiac diseases. Beyond diagnosis, echocardiographic examination helps in characterizing the severity of the condition since the very first stages. In particular, the application of second-level techniques, speckle tracking echocardiography in particular, can also reveal a subclinical dysfunction, while the standard parameters are in the normality range. The present review describes the potentialities of advanced echocardiography in different settings, including arterial hypertension, atrial fibrillation, diastolic dysfunction, and oncological patients, thus opening up potential starting points for its application as a clinical routine changer.

Ablation of atrial fibrillation beyond pulmonary vein isolation: Do additional ablation lesions impact left atrial function?

INTRODUCTION

Electrical isolation of pulmonary veins (PVI) is a cornerstone for atrial fibrillation (AF) ablation. The overall effect of AF ablation, and especially lesions beyond PVI, on left atrial (LA) function is currently poorly understood. Our aim was to determine if LA function is different in patients after extensive LA ablation compared to PVI only. We performed non-inferiority analysis of LA function after PVI with additional nonpulmonary vein ablation lesions in LA (PVI+) and PVI alone.

METHODS

We studied 68 patients consecutive patients who underwent AF ablation and who had complete transthoracic echocardiogram (TTE) within 12 months before AF ablation and 1-12 months after the procedure. Patients were stratified into two groups: PVI only and PVI+. Primary outcome was change in LA reservoir strain (LASr). Noninferiority margin was defined at 6%.

RESULTS

The PVI only group had a higher proportion of patients with paroxysmal AF (70% vs. 30%). The PVI+ group was observed to have a slightly higher increase in LASr compared to PVI alone (5.0% vs. 4.3%, p < .01 for noninferiority). LASr noninferiority was confirmed when adjusted for age, sex, coronary artery disease, hyperlipidemia, and AF type, rhythm at preprocedure TTE in a multivariable linear regression model, 90% CI (-5.46 to 2.04), p < .01.

CONCLUSION

LA functional improvement evaluated by LASr was noninferior after PVI with additional LA ablation lesions compared to PVI alone. These findings were confirmed when adjusted for confounding clinical variables, suggesting that more extensive ablation does not negatively affect LA function.

Conventional and two-dimensional strain echocardiography in predicting postoperative atrial fibrillation after coronary artery bypass grafting surgery

Background

Atrial fibrillation (AF) is a common complication after heart surgeries. Advances in imaging technologies and an understanding of the pathophysiology of preoperative left atrial (LA) dysfunction can lead to more definitive potential therapeutic approaches. This study aimed to determine the role of conventional echocardiography and LA two-dimensional (2D) strain echocardiography in assessing LA function and predicting POAF after CABG surgery.

Methods

All patients with sinus rhythm who underwent CABG surgery were enrolled. All the patients had undergone conventional echocardiography and LA 2D-strain echocardiography 24 hours before surgery. In addition to demographic, clinical, and perioperative features, electrocardiogram (ECG) and Holter monitoring were recorded.

Results

Of the 105 patients included, 85 patients (81%) were men with a mean age of 60.26±10.61 years. POAF was seen in 22.9% of patients during hospitalization, and AF duration was 10 hours (median; IQR: 2.0-19.5). AF patients had a higher LA volume index (LAVI) than patients with sinus rhythm (p=0.018). Patients with sinus rhythm had higher rates of LA reservoir (26.97±6.87 VS. 20.46±4.27, p<0.001), LA contractile (14.98±3.68 VS. 12.76±3.72, p =0.012) and LA global strain (24.28±6.57 VS. 17.71±4.11, p<0.001) than AF patients. The results of the multivariate logistic regression showed that LAVI (p=0.014) and LA global strain (p=0.027) were independent predictors of AF detection.

Conclusion

Compared to conventional echocardiography, 2D-strain echocardiography is a more effective diagnostic method to predict the possibility of post-CABG AF.

Clinical utility of left atrial strain in predicting atrial fibrillation recurrence after catheter ablation: An up-to-date review

Rhythm control is the core part of the integrated management of atrial fibrillation (AF), especially in the early stages. Despite advances in catheter ablation (CA), the recurrence rate of AF after CA remains high. As a result, stratification and early management of AF recurrence after CA are critical. Currently, predictors of recurrence of AF after CA are mostly based on dysfunction caused by structural remodeling, apart from traditional risk factors. Atrial strain is a recently developed important parameter for detecting the deformability of atrial myocardium during the cardiac cycle prior to atrial remodeling. Although there is only preliminary evidence, atrial strain is still a promising parameter in predicting the recurrence of AF after CA at an early stage. This review focuses on the evaluation of atrial strain, the current applications of atrial strain in assessing atrial function, and predicting the recurrence of AF after CA. We summarize the contents related as follows: (1) CA for rhythm control in AF; (2) Evaluation methods of atrial strain; (3) Atrial strain in the remodeling and reverse remodeling of AF; and (4) Clinical applications of atrial strain in predicting the recurrence of AF after CA. Although there is accumulating evidence on the role of decreased atrial strain in the early prediction of AF recurrence, atrial strain is limited in clinical practice for lacking exact cut-off values and difficulty in distinguishing specific function phases of the atrium. More research is needed in the future to add strength to the early prediction value of atrial strain in AF recurrences.

From Left Atrial Dimension to Curved M-Mode Speckle-Tracking Images: Role of Echocardiography in Evaluating Patients with Atrial Fibrillation

Left atrial (LA) enlargement and dysfunction increase the risk of atrial fibrillation (AF). Traditional echocardiographic evaluation of the left atrium has been limited to dimensional and semi-quantification measurement of the atrial component of ventricular filling, with routine measurement of LA function not yet implemented. However, functional parameters, such as LA emptying fraction (LAEF), may be more sensitive markers for detecting AF-related changes than LA enlargement. Speckle-tracking echocardiography has proven to be a feasible and reproducible technology for the direct evaluation of LA function. The clinical application, advantages, and limitations of LA strain and strain rate need to be fully understood. Furthermore, the prognostic value and utility of this technique in making therapeutic decisions for patients with AF need further elucidation. Deep learning neural networks have been successfully adapted to specific tasks in echocardiographic image analysis, and fully automated measurements based on artificial intelligence could facilitate the clinical diagnostic use of LA speckle-tracking images for classification of AF ablation outcome. This review describes the fundamental concepts and a brief overview of the prognostic utility of LA size, LAEF, LA strain and strain rate analyses, and the clinical implications of the use of these measures.

Left atrial contractile strain predicts recurrence of atrial tachyarrhythmia after catheter ablation

BACKGROUND

Despite improvement in treatment strategies of atrial fibrillation (AF), a considerable number of patients still experience recurrence of atrial tachyarrhythmia (ATA) following catheter ablation (CA). This study aimed to investigate the prognostic value of left atrial (LA) deformation analysis in a large group of patients undergoing CA for AF.

METHODS

This study included 678 patients with AF. Echocardiography including two-dimensional speckle tracking echocardiography (2DSTE) was performed in all patients prior to CA. Logistic regression analysis was used to assess the association between ATA recurrence and LA strain during reservoir phase (LASr), LA strain during contraction phase (LASct), and LA strain during conduit phase (LAScd).

RESULTS

During one-year follow-up, 274 (40%) experienced ATA recurrence. Median age of the included study population was 63.2 years (IQR: 55.5, 69.5) and 485 (72%) were male. Patients with recurrence had lower LASr (22.6% vs. 25.1%, p = 0.001) and LASct (10.7% vs. 12.4%, p < 0.001). No difference in LAScd was observed. After adjusting for potential clinical and echocardiographic confounders LASr (OR = 1.04, CI95% [1.01; 1.07], p = 0.015, per 1% decrease) and LASct (OR = 1.06, CI95% [1.02; 1.11], p = 0.007, per 1% decrease) remained independent predictors of recurrence. However, in patients with a normal-sized LA (LA volume index<34 mL/m²), only LASct remained an independent predictor of recurrence (OR = 1.07, CI95% [1.01; 1.12], p = 0.012, per 1% decrease).

CONCLUSION

In patients undergoing CA for AF, LA deformation analysis by 2DSTE could be of use in risk stratification in clinical practice regarding ATA recurrence, even in patients with a normal-sized LA.

Evaluation of atrial fibrosis in atrial fibrillation patients with three different methods

BACKGROUND

The presence of atrial fibrosis has already been known as a risk factor for atrial fibrillation (AF) development. We aimed to evaluate atrial fibrosis with previously defined three different methods, which were cardiac magnetic resonance imaging (C-MRI), echocardiographic strain imaging, and biomarkers and show the relationship between these methods in patients with AF scheduled for cryoballoon ablation.

METHODS

A total of 30 patients were enrolled. Atrial T1 relaxation durations were measured using C-MRI before the procedure of atrial fibrillation catheter ablation. Fibroblast growth factor-21 (FGF-21) and fibroblast growth factor-23 (FGF-23) levels were measured at serum derived from the femoral artery (Peripheral FGF 21 and 23) and left atrium blood samples (Central FGF 21 and 23) before catheter ablation. Preprocedural transthoracic echocardiography was performed. The median follow-up duration for atrial tachyarrhythmia (ATa) recurrence was 13 (12-18 months) months.

RESULTS

The mean ages of the study group were 55.23 ± 12.37 years, and there were 17 (56.7%) female patients in study population. There were negative correlations between post contrast T1 relaxation durations of both posterior and posterosuperior atrium, and central FGF-23 (r: - 0.561; p = 0.003; r:-0.624; p = 0.001; Posterior T1 vs. central FGF-23 levels and Posterosuperior T1 vs central FGF-23 levels, respectively). The positive correlations were observed between postcontrast posterior T1 relaxation durations and left ventricle ejection fraction (r:0.671; p = 0.001); left atrial emptying fraction (r:0.482; p = 0.013); peak atrial longitudinal strain (r:0.605; p = 0.001), and peak atrial contraction strain (r:0.604; p = 0.001). Also negative correlation was observed between postcontrast posterior T1 relaxation durations, and left atrial volume index (r: - 0.467; p = 0.016).

Incremental value of left atrial strain to predict atrial fibrillation recurrence after cryoballoon ablation

Objective

Atrial fibrillation (AF) recurrence occurs in approximately 25% of the patients undergoing cryoballoon ablation (CBA), leading to repeated ablations and complications. Left atrial (LA) dilation has been proposed as a predictor of AF recurrence. However, LA strain is a surrogate marker of LA mechanical dysfunction, which might appear before the enlargement of the LA. The purpose of this study was to evaluate the additional predictive value of LA function assessed using strain echocardiography for AF recurrence after CBA.

Methods

172 consecutive patients (62.2 ± 12.2 years, 61% male) were prospectively analyzed. Echocardiography was performed before CBA. Blanking period was defined as the first three months post-ablation. The primary endpoint was AF recurrence after the blanking period.

Results

50 (29%) patients had AF recurrence. In the overall study population, peak atrial longitudinal strain (PALS) ≤ 17% had the highest incremental predictive value for AF recurrence (HR = 9.45, 95%CI: 3.17–28.13, p < 0.001). In patients with non-dilated LA, PALS≤17% remained an independent predictor of AF recurrence (HR = 5.39, 95%CI: 1.66–17.52, p = 0.005).

Conclusions

This study showed that LA function assessed by PALS provided an additional predictive value for AF recurrence after CBA, over LA enlargement. In patients with non—dilated LA, PALS also predicted AF recurrence. These findings emphasize the added value of LA strain, suggesting that it should be implemented in the systematic evaluation of AF patients before CBA.

Rationale and design of the rigorous atrial analysis in advanced interatrial block (ARABIA) prospective study

BACKGROUND

Advanced interatrial block (IAB) is present in 10% of subjects ≥75 years and is associated with the risk of clinical events.

METHODS AND RESULTS

Prospective multicenter study that will include subjects ≥75 years without exclusion criteria (indication for anticoagulation, cardiac devices, severe valve disease, systolic dysfunction, moderate or severe cognitive impairment, poor echocardiographic window, non-sinus rhythm or partial IAB, stroke, and life expectancy <2 years). A total of 356 subjects, 178 patients with advanced IAB (exposed) and 178 matched individuals with normal P-wave (non-exposed) will be included. Electrocardiogram and advanced transthoracic echocardiography will be performed. Two substudies will include magnetic resonance imaging: cardiac (86 subjects, 43 exposed, and 43 non-exposed) and brain (86 subjects, 43 exposed, and 43 non-exposed). The follow-up will be 2 years. Our main objective is to determine the association of advanced IAB, P-wave duration, and atrial imaging parameters (I] atrial global longitudinal strain, II] maximal left atrial volume index, III] left atrial ejection fraction, IV] left atrial fibrosis - % total left atrial area V] inter- and intra-atrial asynchrony/dyssynchrony) with clinical events (atrial fibrillation, stroke, cognitive impairment, and mortality). The secondary objective is to assess the association of the P-wave duration with atrial imaging parameters and of both with cerebral microemboli in magnetic resonance imaging.

CONCLUSION

Our study will provide data regarding the association of advanced IAB, P-wave duration, and atrial imaging parameters with clinical events. We will also assess the association P-wave duration-atrial imaging parameters-cerebral microemboli.

The role of left atrial peak systolic strain in atrial fibrillation recurrence after catheter ablation. A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis was performed to assess the prognostic role of left atrial peak systolic longitudinal strain (LA-PLSsys) as a predictor of atrial fibrillation (AF) recurrence after catheter ablation.

METHODS

We systematically searched major electronic databases and grey literature for studies assessing the role of pre-ablation LA-PLSsys, measured in at least two segments, in post-ablation AF recurrence, after a follow-up period of at least 6 months.

RESULTS

Seventeen eligible studies were included, resulting in 1704 patients (68.6% men) with a pooled mean age of 59.9 ± 10.6 years, 65.9% with paroxysmal AF. Recurrence occurred in 32.7% of patients. Those without recurrence had significantly higher LA-PLSsys (pooled mean ± SD: 22.22 ± 10.64%, weighted mean difference: 5.43%, 95%CI: 4.03-6.84%, I²: 82.7%). Subgroup analysis revealed that the methodology used (echocardiographic view and segments assessed), was a significant source of heterogeneity (p = 0.02). Meta-regression analysis demonstrated that the effect size was inversely related to the baseline LA volume index (p = 0.004), while concerns are also raised about patients with extremely high/low pre-ablation LA strain.

CONCLUSIONS

Pre-ablation LA-PLSsys seems to be a useful predictor of post-ablation AF recurrence, that could optimise patients selection. Nevertheless, the substantial heterogeneity that was noted may limit its clinical use. Further investigation using a uniform methodological assessment technique is required to derive a reference range, with adequate positive and negative predictive value for recurrence.

How to do left atrial late gadolinium enhancement: a review

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.

Natural History of Arrhythmia After Successful Isolation of Pulmonary Veins, Left Atrial Posterior Wall, and Superior Vena Cava in Patients With Paroxysmal Atrial Fibrillation: A Multi-Center Experience

Background We evaluated long-term outcome of isolation of pulmonary veins, left atrial posterior wall, and superior vena cava, including time to recurrence and prevalent triggering foci at repeat ablation in patients with paroxysmal atrial fibrillation with or without cardiovascular comorbidities. Methods and Results A total of 1633 consecutive patients with paroxysmal atrial fibrillation that were arrhythmia-free for 2 years following the index ablation were classified into: group 1 (without comorbidities); n=692 and group 2 (with comorbidities); n=941. We excluded patients with documented ablation of areas other than pulmonary veins, the left atrial posterior wall, and the superior vena cava at the index procedure. At 10 years after an average of 1.2 procedures, 215 (31%) and 480 (51%) patients had recurrence with median time to recurrence being 7.4 (interquartile interval [IQI] 4.3-8.5) and 5.6 (IQI 3.8-8.3) years in group 1 and 2, respectively. A total of 201 (93.5%) and 456 (95%) patients from group 1 and 2 underwent redo ablation; 147/201 and 414/456 received left atrial appendage and coronary sinus isolation and 54/201 and 42/456 had left atrial lines and flutter ablation. At 2 years after the redo, 134 (91.1%) and 391 (94.4%) patients from group 1 and 2 receiving left atrial appendage/coronary sinus isolation remained arrhythmia-free whereas sinus rhythm was maintained in 4 (7.4%) and 3 (7.1%) patients in respective groups undergoing empirical lines and flutter ablation (P<0.001). Conclusions Very late recurrence of atrial fibrillation after successful isolation of pulmonary veins, regardless of the comorbidity profile, was majorly driven by non-pulmonary vein triggers and ablation of these foci resulted in high success rate. However, presence of comorbidities was associated with significantly earlier recurrence.

Quantification of left atrial contractile function using two-dimensional speckle tracking echocardiography in horses after conversion of atrial fibrillation to sinus rhythm

INTRODUCTION/OBJECTIVES

In horses, persistent atrial dysfunction is a prognostic indicator of recurrence of atrial fibrillation (AF). The objective of this study was to quantify left atrial (LA) contractile function in Warmblood horses after successful cardioversion of AF to sinus rhythm, using standard two-dimensional echocardiography (2DE) and two-dimensional speckle tracking (2DST) analyses, and to provide proof-of-concept for use of 2DST to detect LA contractile dysfunction in horses.

ANIMALS, MATERIALS, AND METHODS

Nineteen Warmblood horses with AF and successful transvenous electrical cardioversion (TVEC) or medical cardioversion using quinidine sulfate (QS) were included. Echocardiography was performed at 24 hr, 72 hr, and 1-6 months after cardioversion. Conventional 2DE-derived indices of LA size and function and global longitudinal strain (S_L) and longitudinal strain rate (SR_L) during LA contractile function were measured to detect differences in LA size and function over time and between treatment modalities. The association between 2DE-derived indices and global S_L and SR_L, respectively, and the agreement of the variables to detect LA dysfunction were assessed.

RESULTS

Global S_L and SR_L, as well as active LA fractional area change (FAC) identified cases with LA dysfunction after TVEC and QS cardioversion and proved useful to demonstrate LA functional recovery over time. Agreement between active LA FAC and S_L and SR_L, respectively, to diagnose atrial dysfunction was substantial to fair at 24 hr after cardioversion and decreased with time.

CONCLUSION

This study shows that 2DST is useful to quantify LA contractile dysfunction in horses after cardioversion of AF.

Novel Approaches in Cardiac Imaging for Non-invasive Assessment of Left Heart Myocardial Fibrosis

In the past, the identification of myocardial fibrosis was only possible through invasive histologic assessment. Although endomyocardial biopsy remains the gold standard, recent advances in cardiac imaging techniques have enabled non-invasive tissue characterization of the myocardium, which has also provided valuable insights into specific disease processes. The diagnostic accuracy, incremental yield and prognostic value of speckle tracking echocardiography, late gadolinium enhancement and parametric mapping modules by cardiac magnetic resonance and cardiac computed tomography have been validated against tissue samples and tested in broad patient populations, overall providing relevant clinical information to the cardiologist. This review describes the patterns of left ventricular and left atrial fibrosis, and their characterization by advanced echocardiography, cardiac magnetic resonance and cardiac computed tomography, allowing for clinical applications in sudden cardiac death and management of atrial fibrillation.

Left Atrial Strain Identifies Increased Atrial Ectopy in Patients with Beta-Thalassemia Major

Patients with beta-thalassemia major (β-ΤΜ) may develop cardiac arrhythmias through a multifactorial mechanism. The current study evaluated the association of cardiac structure and function on echocardiography with atrial ectopic burden on 24-hour tape recording in β-ΤΜ patients. This prospective study included consecutive β-ΤΜ patients. Demographic, laboratory, echocardiographic, cardiac magnetic resonance (CMR) T2* and 24-hour tape recording data were prospectively collected. The patients were classified according to the median value of premature atrial contractions (PACs) on 24-hour tape. In total, 50 β-TM patients (37.6 ± 9.1 years old, 50% male) were divided in 2 groups; PACs ≤ 24/day and > 24/day. Patients with PACs > 24/day were treated with blood transfusion for a longer period of time (39.0 ± 8.6 vs. 32.0 ± 8.9 years, p < 0.007), compared to their counterparts. Older age (OR: 1.121, 95% CI: 1.032–1.217, p = 0.007), longer duration of blood transfusion (OR:1.101, 95% CI:1.019–1.188, p = 0.014), larger LV end-diastolic diameter (OR: 4.522, 95% CI:1.009–20.280, p = 0.049), higher values of LA peak systolic strain (OR: 0.869, 95% CI: 0.783–0.964, p = 0.008), higher MV E/E′ average (OR: 1.407, 95% CI: 1.028–1.926, p = 0.033) and higher right ventricular systolic pressure (OR: 1.147, 95% CI: 1.039–1.266, p = 0.006) were univariably associated with PACs > 24/day. LA peak systolic strain remained significantly associated with PACs > 24/day after adjusting for the duration of blood transfusions or for CMR T2*. The multivariable model including blood transfusion duration and LA peak systolic strain was the most closely associated with PACs > 24/day. Receiver operating characteristic curve analysis identified a left atrial peak systolic strain of 31.5%, as the best cut-off value (83% sensitivity, 68% specificity) for prediction of PACs > 24/day. In β-TM patients, LA peak systolic strain was associated with the atrial arrhythmia burden independently to the duration of blood transfusions and CMR T2*.

Antithrombotic Treatment after Atrial Fibrillation Ablation

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Atrial fibrillation is a major cause of debilitating strokes and anticoagulation is an established and indispensable therapy for reducing their rate. Ablation of the arrhythmia has emerged as a putative means of disrupting its natural course by isolating its triggers and modifying its substrate, dependent on the chosen method. An important dilemma lies in the need for continuation of anticoagulation therapy in those previously receiving it following an, apparently, successful intervention, purportedly preventing arrhythmia recurrence with considerably high rates. Current guidance, given scarcity of high-quality data from randomized trials, focuses on established knowledge and recommends anticoagulation continuation based solely on estimated thromboembolic risk. In the present review, it will be attempted to summarize the pathophysiological rationale for maintaining anticoagulation post-successful ablation, along with the latter’s definition, including the two-fold effects of the procedure per se on thrombogenicity. Available evidence pointing to an overall clinical benefit of anticoagulation withdrawal following careful patient assessment will be discussed, including ongoing randomized trials aiming to offer definitive answers. Finally, the proposed mode of post-ablation anticoagulation will be presented, including the emerging, guideline-endorsed, role of direct oral anticoagulants in the field, altering cost/benefit ratio of anticoagulation and potentially affecting the very decision regarding its discontinuation.

Usefulness of left atrial speckle tracking echocardiography in predicting recurrence of atrial fibrillation after radiofrequency ablation: a systematic review and meta-analysis

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.

Atrial Cardiomyopathy: An Unexplored Limb of Virchow's Triad for AF Stroke Prophylaxis

The most dreaded complication of atrial fibrillation is stroke, and 70–80% of patients with AF-related stroke die or become disabled. The mechanisms of thromboembolism in AF are multifactorial, with evidence demonstrating that all three criteria of Virchow's triad are satisfied in AF: abnormal stasis of blood, endothelial damage, and hypercoagulability. Mechanistic insights into the latter two limbs have resulted in effective stroke prophylactic therapies (left atrial appendage occlusion and oral anticoagulants); however, despite these advances, there remains an excess of stroke in the AF population that may be due, in part, to a lack of mechanistic understanding of atrial hypocontractility resulting in abnormal stasis of blood within the atrium. These observations support the emerging concept of atrial cardiomyopathy as a cause of stroke. In this Review, we evaluate molecular, translational, and clinical evidence for atrial cardiomyopathy as a cause for stroke from AF, and present a rationale for further investigation of this largely unaddressed limb of Virchow's triad in AF.

Left atrial structure and function predictors of recurrent fibrillation after catheter ablation: a systematic review and meta-analysis

BACKGROUND

Catheter ablation (CA) has become a conventional treatment for atrial fibrillation (AF), but remains with high recurrence rate. The aim of this meta-analysis was to determine left atrial (LA) structure and function indices that predict recurrence of AF.

METHODS

We systematically searched PubMed-Medline, EMBASE, Scopus, Google Scholar and the Cochrane Central Registry, up to September 2017 in order to select clinical trials and observational studies which reported echocardiographic predictors of AF recurrence after CA. Eighty-five articles with a total of 16 126 patients were finally included.

RESULTS

The pooled analysis showed that after a follow-up period of 21 ± 12 months, patients with AF recurrence had larger LA diameter with weighted mean difference (WMD: 2·99 ([95% CI 2·50-3·47], P<0·001), larger LA volume index (LAVI) maximal and LAVI minimal (P<0·0001 for both), larger LA area (P<0·0001), lower LA strain (P<0·0001) and lower LA total emptying fraction (LA EF) (P<0·0001) compared with those without AF recurrence. The most powerful LA predictors (in accuracy order) of AF recurrence were as follows: LA strain <19% (OR: 3·1[95% CI, -1.3-10·4], P<0·0001), followed by LA diameter ≥50 mm (OR: 2·75, [95% CI 1·66-4·56,] P<0·0001), and LAVmax >150 ml (OR: 2·25, [95% CI, 1.1-5·6], P = 0·0002).

CONCLUSIONS

Based on this meta-analysis results, a dilated left atrium with diameter more than 50 mm and volume above 150 ml or myocardial strain below 19% reflect an unstable LA that is unlikely to hold sinus rhythm after catheter ablation for atrial fibrillation.

Assessment of Left Atrial Function in Patients with Paroxysmal, Persistent, and Permanent Atrial Fibrillation using Two-Dimensional Strain

Background and purpose

Atrial fibrillation (AF) has a progressive nature, leading to structural, functional, and electrical changes in the left atrium (LA). Enhanced response to treatment in patients with AF can be achieved through improved knowledge of atrial structure and a better understanding of its function. The aim of this study was to assess LA strain and its determinants in patients with paroxysmal (PAF), persistent (PsAF), and permanent AF (PmAF).

Methods

Fifty-eight patients with registered non-valvular AF were divided into 3 groups depending on the type of AF. The participants underwent transthoracic echocardiography to assess the anatomy and function of heart chambers. Left atrial longitudinal strain (LALS) was measured in four-chamber projections using two-dimensional speckle tracking echocardiography.

Results

Patients with PAF had higher LALS (15.7±12.0) when compared to those with PsAF (4.3±7.9) and PmAF (5.8±7.8, all P=0.003). Multiple linear regression showed that the independent predictors of LALS were diastolic blood pressure (β=0.95, R2=0.88) in the PAF group; left atrial area (β=-0.56) and creatinine (β=-0.63, R2=0.58) in the PsAF group; AF duration (β=0.89) in the PmAF group (R2=0.72).

Conclusion

LA strain has different determinants depending on AF type. LA size, renal function, and AF duration determine LALS in long-lasting AF. LA strain is a simple and accurate technique to estimate LA dysfunction in patients with long-lasting AF.

Use of Contemporary Imaging Techniques for Electrophysiological and Device Implantation Procedures

Recent technological advances in cardiac imaging allow the visualization of anatomic details up to millimeter size in 3-dimensional format. Thus, it is not surprising that electrophysiologists increasingly rely upon cardiac imaging for the diagnosis, treatment, and subsequent management of patients affected by various arrhythmic disorders. Cardiac imaging methods reviewed in the present work involve: 1) the prediction of arrhythmic risk for sudden cardiac death in patients with heart disease; 2) catheter ablation of atrial fibrillation or ventricular tachycardia; and 3) cardiac resynchronization therapy. Future integration of diagnostic and interventional cardiac imaging will further increase the effectiveness of cardiac electrophysiological procedures and will help in delivering patient-specific therapies with ablation and cardiac implantable electronic devices.

Combined assessment of left atrial volume parameters for predicting recurrence of atrial fibrillation following pulmonary vein isolation in patients with paroxysmal atrial fibrillation

OBJECTIVES

Our aim was to test the hypothesis that comprehensive simplified left atrial (LA) assessment derived from routine echocardiography may be more useful than assessment of LA volume alone for predicting atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI).

METHODS

We studied 156 patients with paroxysmal AF (PAF) who had undergone PVI. Echocardiography was performed within two days before PVI. Maximum (Max-LAVi) and minimum LA volume index (Min-LAVi) were calculated with the biplane modified Simpson's method, and then normalized to the body surface area. On the basis of previous findings, the predefined cutoff value of Max-LAVi for AF recurrence was set at Max-LAVi ≥ 34 mL/m² . ΔLA volume index (ΔLAVi) was also calculated as Max-LAVi minus Min-LAVi. The follow-up period after PVI was 24 months.

RESULTS

AF recurrence was observed in 35 patients. Multivariate logistic regression analysis showed that ΔLAVi (odds ratio [OR]: 1.131; 95% confidence interval [CI]: 1.057-1.221; P < 0.001) was an independent predictor of AF recurrence. Sequential logistic regression models for predicting AF recurrence revealed that a model based on clinical variables including age, gender and AF duration (χ²  = 1.65) was improved by the addition of Max-LAVi ≥ 34 mL/m² (χ²  = 13.8; P < 0.001), and further improved by the addition of ΔLAVi (χ²  = 18.2; P = 0.036). Of note is that only 1.02 ± 0.10 minutes per patient was needed to obtain a comprehensive LA assessment that included Max-LAVi, Min-LAVi, and ΔLAVi.

CONCLUSION

This easy-to-use comprehensive simplified LA approach from routine echocardiography may well have clinical implications for better management of PAF patients.

Echocardiographic predictors of atrial fibrillation recurrence after catheter ablation: A literature review

BACKGROUND

Catheter ablation (CA) is a well-known treatment option for patients with symptomatic drug-resistant atrial fibrillation (AF). Multiple factors have been identified to determine AF recurrence after CA, however their predictive value is rather small. Identification of novel predictors of CA outcome is therefore of primary importance to reduce health costs and improve long-term results of intervention. The recurrence of AF following CA is related to severity of left ventricular (LV) dysfunction, extent of atrial dilatation and fibrosis. The aim of this paper was to present and discuss the latest studies on the utility of echocardiographic parameters in terms of CA effectiveness in patients with paroxysmal and persistent AF.

METHODS

PubMed, Google Scholar, EBSCO databases were searched for studies reporting echocardiographic preprocedural predictors of AF recurrence after CA. LV systolic and diastolic function, as well as atrial size, strain and dyssynchrony were taken into consideration.

RESULTS

Twenty one full-text articles were analyzed, including three meta-analyses. Several echocardiographic parameters have been reported to determine a risk of AF recurrence after CA. There are conventional methods that measure left atrial size and volume, LV ejection fraction, parameters assessing LV diastolic dysfunction, and methods using more innovative technologies based on speckle tracking echocardiography to determine left atrial synchrony and strain. Each of these parameters has its own predictive value.

CONCLUSIONS

Regarding CA effectiveness, every patient has to be evaluated individually to estimate the risk of AF recurrence, optimally using a combination of several echocardiographic parameters.