Stiff left atrial syndrome after catheter ablation for atrial fibrillation: Clinical characterization, prevalence, and predictors

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

Stiff right atrial syndrome? A complex clinical case report utilizing multimodality imaging and invasive hemodynamics

Background

Stiff left atrial syndrome is a well-established cause of heart failure symptoms. A parallel entity involving the right atrium (RA) has not previously been described. We present a case of refractory right heart failure (RHF) 12 years following orthotopic heart transplantation.

Case summary

Patient underwent annuloplasty ring placement for severe tricuspid regurgitation in 2018 and kidney transplantation in 2020. The use of multimodality imaging and a multidisciplinary approach suggested a stiff RA as a potential etiology to refractory symptoms. Redo-heart and kidney transplantation in March 2021 led to the resolution of symptoms without recurrence.

Discussion

We propose stiff right atrial syndrome that may need to be considered in the setting of refractory RHF primarily suggested by significant right atrial enlargement and restrictive physiology.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Left Atrial Stiffness Increases after Trans-Catheter Atrial Septal Closure

BACKGROUND

Transcatheter atrial septal closures for secundum atrial septal defects (ASD) have demonstrated favorable clinical outcomes. However, the impact of device implantation on the stiffness of the left atrium remains unclear.

METHOD

Patients with secundum ASD undergoing transcatheter closure and follow-up right heart catheterization at six months were included. We investigated the relationship between post-procedural (E/e' ratio)/(LAs strain) ratio, an index of left atrial stiffness, and baseline characteristics, including echocardiographic and hemodynamic parameters.

RESULTS

Forty patients were included (median 69 (56, 75) years, 12 men, and pulmonary systemic flow ratio 2.27 (1.96, 2.86)). Trans-catheter ASD closure was successfully performed without any major complications, accompanying a significant reduction in right ventricular to left ventricular size ratio from 1.04 (0.87, 1.13) to 0.74 (0.66, 0.86) (p < 0.01). The (E/e' ratio)/(LAs strain) ratio was markedly elevated the day after the procedure and was further increased 6 months later (before: 0.25 (0.17, 0.34), 1 day later: 0.34 (0.27, 0.50), 6 months later: 0.43 (0.27, 0.76), p < 0.01). The groups with higher (E/e' ratio)/(LAs strain) ratios at 6 months had significantly more severe heart failure conditions including lower cardiac output and higher plasma B-type natriuretic peptides.

CONCLUSIONS

Patients undergoing transcatheter ASD closure experienced improvement in hemodynamics and clinical symptoms but an elevation in left atrial stiffness post-procedure. The clinical ramifications of this finding, particularly during the longer-term observation period subsequent to ASD closure, warrant further investigation.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Comparison of electrogram characteristics in persistent atrial fibrillation

INTRODUCTION

Multiple analysis techniques evaluate electrograms during atrial fibrillation (AF), but none have been established to guide catheter ablation. This study compares electrogram properties recorded from multiple right (RA) and left atrial (LA) sites.

METHODS

Multisite LA/RA mapping (281 ± 176/239 ± 166 sites/patient) was performed in 42 patients (30 males, age 63 ± 9 years) undergoing first (n = 32) or redo-AF ablation (n = 10). All electrogram recordings were visually reviewed and artifactual signals were excluded leaving a total of 21 846 for analysis. Electrogram characteristics evaluated were cycle length (CL), amplitude, Shannon's entropy (ShEn), fractionation interval, dominant frequency, organizational index, and cycle length of most recurrent morphology (CLR ) from morphology recurrence plot analysis.

RESULTS

Electrogram characteristics were correlated to each other. All pairwise comparisons were significant (p < .001) except for dominant frequency and CLR (p = .59), and amplitude and dominant frequency (p = .38). Only ShEn and fractionation interval demonstrated a strong negative correlation (r = -.94). All other pairwise comparisons were poor to moderately correlated. The relationships are highly conserved among patients, in the RA versus LA, and in those undergoing initial versus redo ablations. Antiarrhythmic drug therapy did not have a significant effect on electrogram characteristics, except minimum ShEn. Electrogram characteristics associated with ablation outcome were shorter minimum CLR , lower minimum ShEn, and longer mimimum CL. There was minimal overlap between the top 10 sites identified by one electrogram characteristic and the top 10 sites identified by the other 10 characteristics.

CONCLUSION

Multiple techniques can be employed for electrogram analysis in AF. In this analysis of eight different electrogram characteristics, seven were poorly to moderately correlated and do not identify similar locations. Only some characteristics were predictive of ablation outcome. Further studies to consider electrogram properties, perhaps in combination, for categorizing and/or mapping AF are warranted.

Omics and Extreme Phenotyping Reveal Longitudinal Association Between Left Atrial Size and Pulmonary Vascular Resistance in Group 2 Pulmonary Hypertension

BACKGROUND

Left heart disease is the most common cause of pulmonary hypertension (PH) and is frequently accompanied by increases in pulmonary vascular resistance. However, the distinction between phenotypes of PH due to left heart disease with a normal or elevated pulmonary vascular resistance-isolated postcapillary PH (IpcPH) and combined pre- and postcapillary PH (CpcPH), respectively-has been incompletely defined using unbiased methods.

METHODS AND RESULTS

Patients with extremes of IpcPH versus CpcPH were identified from a single-center record of those who underwent right heart catheterization. Individuals with left ventricular ejection fraction <40% or with potential causes of PH beyond left heart disease were excluded. Medication usage in IpcPH and CpcPH was compared across Anatomical Therapeutic Chemical classes and identified vitamin K antagonists as the only medication with pharmacome-wide significance, being more commonly used in CpcPH and for an indication of atrial fibrillation in ≈90% of instances. Accordingly, atrial fibrillation prevalence was significantly higher in CpcPH in a phenome-wide analysis. Review of echocardiographic data most proximal to right heart catheterization revealed that left atrial diameter indexed to body surface area-known to be associated with atrial fibrillation-was increased in CpcPH regardless of the presence of atrial fibrillation. An independent cohort with serial right heart catheterizations and PH-left heart disease showed a significant positive correlation between change in left atrial diameter indexed to body surface area and change in pulmonary vascular resistance.

CONCLUSIONS

Guided by pharmacomic and phenomic screens in a rigorously phenotyped cohort, we identify a longitudinal association between left atrial diameter indexed to body surface area and pulmonary vascular resistance with implications for the future development of diagnostic, prognostic, and therapeutic tools.

Pulsed field ablation for atrial fibrillation - Lessons from magnetic resonance imaging

Pulsed field ablation (PFA) is a promising technology for the treatment of atrial fibrillation (AF). Due to its unique tissue selectivity, PFA potentially bears superior characteristics as compared to established thermal energy sources in AF ablation procedures. Cardiovascular magnetic resonance imaging (CMR) using late gadolinium enhancement (LGE) is an established tool in the analysis of myocardial fibrosis representing atrial cardiomyopathy as well as ablation-induced atrial scar formation following catheter ablation with thermal energy. Mechanisms of atrial lesion formation differ between thermal ablation and electroporation and its impact on results of CMR imaging are not fully understood until now. In this review article, the potential of CMR imaging for PFA lesion assessment and available data are discussed. Further, additional needs to adopt imaging approaches to the cellular mechanisms of electroporation are considered.

Heart Failure with Preserved Left Ventricular Ejection Fraction: A Complex Conundrum Simply Not Limited to Diastolic Dysfunction

Over the last two decades, the changing paradigm of heart failure with preserved ejection fraction (HFpEF) has transformed our understanding not only of the pathophysiology of this clinical entity but also the diagnostic and therapeutic approaches aimed at treating this complex patient population. No longer HFpEF should be seen as simply left ventricular diastolic dysfunction but as a group of that in addition of having small and thick left ventricles with abnormal diastolic filling patterns as their main pathophysiologic abnormality; they also have whole host of different abnormalities. In fact, this heterogeneous clinical entity embodies numerous mechanisms and is linked to multiorgan dysfunction, with hypertension and obesity playing a major role. Although we have gained an enormous amount of understanding not only on the causes but also the downstream effects of HFpEF, there is still much to be learned before we can fully comprehend this complex clinical entity. It is the main intention of this review to synthesize the most recent attributes, mechanism, diagnostic tools, and most useful therapeutic alternatives to be considered when evaluating patients either complaining of dyspnea on exertion as well as exercise intolerance or those recently admitted with HF symptoms but with normal LVEF in the absence of any other valvular abnormalities.

Lessons from a case with stiff left atrial syndrome complicated by iatrogenic inter-atrial shunts: a case report

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.

Stiff left atrial syndrome with pulmonary veins occlusion after percutaneous radiofrequency ablation: a life-long complication that can lead to heart transplantation

BACKGROUND

Stiff left atrial syndrome (SLAS) and pulmonary vein (PV) occlusion are rare yet potentially major life-long complications after radiofrequency ablation for atrial fibrillation. While mostly controlled by medical management, SLAS can progress to refractory congestive heart failure. Treatment of PV stenosis and occlusion remains a challenging problem with ongoing risk for recurrence regardless of techniques employed. Herein we present the case of a now 51-year-old male with acquired PV occlusion and SLAS who, over the course of eleven years, despite multiple interventions, ultimately required heart transplantation.

CASE PRESENTATION

After undergoing three radiofrequency catheter procedures for paroxysmal atrial fibrillation (AF), a hybrid ablation was planned due to reappearance of symptomatic AF. Preoperative echocardiography and chest computed tomography (CT) revealed an occlusion of both left PVs. Furthermore, left atrial dysfunction, high pulmonary artery and pulmonary wedge pressures were diagnosed as well as an important reduction of the left atrial volume. The diagnosis of stiff left atrial syndrome was made. Primary surgical repair of the left-sided PVs was performed using a pericardial patch as a tubular neo-vein, combined with cryoablation in the left and right atrium to treat the patient's arrhythmia. Initial results were favorable, however, after two years the patient experienced progressive restenosis with hemoptysis. Therefore, stenting of the common left PV was performed. Over the years, progressive right heart failure with severe tricuspid regurgitation developed, despite maximal medical therapy, which led to the need for heart transplantation.

CONCLUSION

The impact of PV occlusion and SLAS after percutaneous radiofrequency ablation can be lifelong and devastating for the clinical course of the patient. Since the presence of a small left atrium could be an important predictor for SLAS in case of redo ablation, preprocedural imaging should guide the operator to an algorithm of a decision-making containing lesion set, energy source, and safety of re-ablation.

Stepwise mapping and ablation algorithm in patients undergoing ablation of unstable, unmappable scar-based atrial tachycardias

BACKGROUND

Scar based atrial tachycardia (AT)'s usually presents with a complex electrophysiological substrate. It is not uncommon that multiple instable ATs are present in a single patient. The aim of this study was to analyze clinical and electrophysiological characteristics of patients who had undergone ablation for instable ATs, and report outcomes of the stepwise substrate ablation procedure during the follow-up.

METHODS

Patients scheduled to undergo AT ablation were screened for enrollment to the study. When instable ATs were diagnosed a stepwise mapping and ablation algorithm was applied to all patients. After the procedure, patients were clinically and electrocardiographically followed.

RESULTS

Twenty-six patients were enrolled in the study. The mean number of ATs observed during the procedures is 3.1±0.7. At the end of the procedure, 18 (69.2%) patients had isolated posterior wall. Anterior mitral line ablation was successfully performed in 13 (50%), mitral isthmus line in 4 (15.4%), roof line in 4 (15.4%) patients. The mean follow-up was 13.5±5.4 months. During the follow-up period 6(23.1%) patients developed arrhythmia recurrence.

CONCLUSIONS

A reasonable mid-term success can be expected in patients with instable ATs undergoing ablation according to the stepwise substrate modification algorithm, however due to extensive ablation it should be reserved for patients where conventional activation mapping cannot be performed.

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.

Prognostic Value of Left Atrial Calcification After Catheter Ablation for Atrial Fibrillation

BACKGROUND

Left atrial calcification (LAC) has occasionally been observed in patients who underwent catheter ablation for atrial fibrillation (AF) by chest computed tomography (CT). However, the evidence regarding the clinical impact of LAC in patients with AF is lacking.

OBJECTIVES

This study aims to investigate the prevalence of LAC in AF patients and evaluate its clinical significance after AF ablation.

METHODS

This observational registry included AF patients who received computed tomography and serial transthoracic echocardiography between January 2010 and November 2017. The primary composite outcome included cardiovascular death, hospitalization for worsening heart failure, and ischemic stroke.

RESULTS

Among 534 patients (72 ± 13 years, 62.5% men) who met the inclusion criteria, 31 (5.8%) had LAC. In multivariable analysis, AF ablation was associated with an 11.8-fold (odds ratio: 11.8; 95% CI: 2.03-227.65) increased risk of the development of LAC in AF patients. Among 218 patients with AF ablation, LAC was detected in 30 (13.8%) patients. Prior stroke (HR: 2.73; 95% CI: 1.08-6.93) and multiple ablation procedures (HR: 4.21; 95% CI: 1.63-10.87) were independently associated with the development of LAC in AF-ablation patients. During a median follow-up of 5.8 years, the primary composite outcome occurred in 11 patients in the LAC group (39.8 per 1,000 person-years) and 10 patients in the non-LAC group (8.9 per 1,000 person-years). The adjusted HR for the primary composite outcome in the LAC group, as compared with the non-LAC group, was 2.81 (95% CI: 1.16-6.84; P = 0.02).

CONCLUSIONS

The presence of LAC was a significant and independent prognostic factor for identifying major adverse cardiovascular events after AF ablation.

Atrial Functional Mitral Regurgitation: A JACC: Cardiovascular Imaging Expert Panel Viewpoint

Functional or secondary mitral regurgitation (MR) is associated with increased cardiovascular morbidity and mortality. Mechanistically, secondary MR is attributable to an imbalance between mitral leaflet tethering and closure forces, leading to poor coaptation. The pathophysiology of functional MR is most often the result of abnormalities in left ventricular function and remodeling, seen in ischemic or nonischemic conditions. Less commonly and more recently recognized is the scenario in which left ventricular geometry and function are preserved, the culprit being mitral annular enlargement associated with left atrial dilatation, termed atrial functional mitral regurgitation (AFMR). This most commonly occurs in the setting of chronic atrial fibrillation or heart failure with preserved ejection fraction. There is variability in the published reports and in current investigations as to the definition of AFMR. This paper reviews the pathophysiology of AFMR and focus on the need for a collective definition of AFMR to facilitate consistency in reported data and enhance much-needed research into outcomes and treatment strategies in AFMR.

Safety, Efficacy and Prognostic Benefit of Atrial Fibrillation Ablation in Heart Failure with Preserved Ejection Fraction

Up to 65% of patients with heart failure with preserved ejection fraction (HFpEF) develop AF during the course of the disease. This occurrence is associated with adverse outcomes, including pump failure death. Because AF and HFpEF are mutually reinforcing risk factors, sinus rhythm restoration may represent a disease-modifying intervention. While catheter ablation exhibits acceptable safety and efficacy profiles, no randomised trials have compared AF ablation with medical management in HFpEF. However, catheter ablation has been reported to result in lower natriuretic peptides, lower filling pressures, greater peak cardiac output and improved functional capacity in HFpEF. There is growing evidence that catheter ablation may reduce HFpEF severity, hospitalisation and mortality compared to medical management. Based on indirect evidence, early catheter ablation and minimally extensive atrial injury should be favoured. Hence, individualised ablation strategies stratified by stepwise substrate inducibility provide a logical basis for catheter-based rhythm control in this heterogenous population. Randomised trials are needed for definitive evidence-based guidelines.

Abnormal left atrial body stiffness is predicted by appendage size: impact of appendage occlusion on left atrial mechanics assessed by pressure-volume analysis

Atrial cardiomyopathy has been recognized as having important consequences for cardiac performance and clinical outcomes. The pathophysiological role of the left atrial (LA) appendage and the effect of percutaneous left atrial appendage occlusion (LAAO) upon LA mechanics is incompletely understood. We evaluated if changes in LA stiffness due to endocardial LAAO can be detected by LA pressure-volume (PV) analysis and whether stiffness parameters are associated with baseline characteristics. Patients undergoing percutaneous endocardial LAAO (n = 25) were studied using a novel PV analysis using near-simultaneous three-dimensional LA volume measurements by transesophageal echocardiography (TEE) and direct invasive LA pressure measurements. LA stiffness (dP/dV, change in pressure with change in volume) was calculated before and after LAAO. Overall LA stiffness significantly increased after LAAO compared with baseline (median, 0.41-0.64 mmHg/mL; P ≪ 0.001). LA body stiffness after LAAO correlated with baseline LA appendage size by indexed maximum depth (Spearman's rank correlation coefficient R_s = 0.61; P < 0.01). LA stiffness change showed an even stronger correlation with baseline LA appendage size by indexed maximum depth (R_s = 0.70; P < 0.001). We found that overall LA stiffness increases after endocardial LAAO. Baseline LA appendage size correlates with the magnitude of increase and LA body stiffness. These findings document alteration of LA mechanics after endocardial LAAO and suggest that the LA appendage modulates overall LA compliance.NEW & NOTEWORTHY Our study documents a correlation of LA appendage remodeling with the degree of chronically abnormal LA body stiffness. In addition, we found that LA appendage size was the baseline parameter that best correlated with the magnitude of a further increase in overall LA stiffness after appendage occlusion. These findings offer insights about the LA appendage and LA mechanics that are relevant to patients at risk for adverse atrial remodeling, especially candidates for LA appendage occlusion.

Consideration Regarding the Analysis of Randomized Controlled Trials in the Era of Evidence-based Medicine

ABSTRACT

Analysis of randomized controlled trials (RCTs) is the cornerstone of evidence-based medicine, therapeutic guidelines and ultimately daily practice. However, 2 issues contribute to cloud the analysis of RCTs. Industry-sponsored RCTs aim at capturing as large indications as possible and clinicians rely excessively on P value statistical significance for the evaluation of the findings. To be most valuable to practitioners, analysis of RCTs needs to provide absolute risk reduction, number of patients needed to treat, fragility index along with the estimation of lost to follow-up patients, and outcome postponement (gain in survival time). We analyzed few major cardiovascular RCTs and assessed the robustness of their findings. Our suggested analytic parameters may be further used in future systematic reviews and meta-analyses.

Long-term Outcome of Patients with Long-standing Persistent Atrial Fibrillation undergoing Ablation Guided by a Novel High-Density Panoramic Mapping System - A Propensity Score Matching Study

Background

Catheter ablation is a current therapeutic approach for atrial fibrillation (AF). However, its efficacy for long-standing persistent AF remains suboptimal.

Objective

The purpose of this study was to test the hypothesis that a panoramic mapping system (CARTOFINDER, Biosense Webster) can guide pulmonary vein (PV) isolation and additional potential AF drivers.

Methods

A total of 76 patients with nonparoxysmal AF referred for ablation guided by a novel high-density panoramic mapping system with CARTOFINDER were prospectively enrolled. Of this cohort, 40 patients (52.6%) had long-standing persistent AF (CARTOFINDER group). We then retrospectively screened the patients with long-standing persistent AF undergoing conventional PV isolation and elimination of non-PV triggers during the contemporary period (conventional group). They were matched at a 1:2 ratio (40 patients in group 1 received ablation guided by CARTOFINDER; 80 patients in group 2 receiving conventional PV isolation and elimination of non-PV triggers).

Results

During follow-up, patients in group 1 had a lower recurrence AF rate than those in group 2 (P = .040). There was no difference in recurrence of atrial flutter (P = .996) and atrial tachycardia (P = .525). In Cox proportional hazards regression analysis, AF duration and PV isolation along with AF driver ablation using a panoramic mapping system with CARTOFINDER both were independent predictors of recurrent AF after catheter ablation of long-standing persistent AF.

Conclusion

Identification of the potential drivers in long-standing AF is crucial. Compared with conventional PV isolation and elimination of non-PV triggers, ablation guided by a high-density panoramic mapping system (CARTOFINDER) might have a better outcome in patients with long-standing persistent AF.

Global Substrate Mapping and Targeted Ablation with Novel Gold-tip Catheter in De Novo Persistent AF

Results from catheter ablation for persistent AF are suboptimal, with no strategy other than pulmonary vein isolation showing clear benefit. Recently employed empirical strategies beyond pulmonary vein isolation involve widespread atrial ablation in all patients and do not take into account patient-specific differences in AF mechanisms or phenotype. Charge density mapping using the non-contact AcQMap system (Acutus Medical) allows visualisation of whole-chamber activation during AF and reveals localised patterns of complex activation thought to represent important mechanisms for AF maintenance that can be targeted with focal ablation. In this review, the authors outline the fundamentals of this technology, the initial data exploring the mechanistic role of activation patterns seen and the application to ablation of persistent AF.

Diabetes Mellitus Is an Independent Risk Factor for a Stiff Left Atrial Physiology After Catheter Ablation for Atrial Fibrillation

Background

Scar tissue formation after catheter ablation for atrial fibrillation (AF) may adversely affect the diastolic properties of the left atrium (LA), which can result in a stiff LA physiology in a small proportion of patients. In this study, we aimed to explore the relationship between diabetes mellitus and a stiff LA physiology after AF catheter ablation (AFCA).

Methods

A total of 1,326 patients who underwent de novo AFCA, and baseline and 1-year follow-up echocardiographies were enrolled. After 1:3 propensity score (PS) matching for age, sex, and AF type, we compared 211 patients with DM with 633 patients without DM. A stiff LA physiology was defined as estimated pulmonary arterial pressure increase of >10 mmHg and a right ventricular systolic pressure of >35 mmHg at 1-year follow-up echocardiography. Pulmonary vascular resistance (PVR) was estimated using echocardiographic parameters.

Results

Among the 844 PS-matched patients, a stiff LA physiology was observed in 32 patients (4.1%). The patients with DM showed a higher peak LA pressure (p < 0.001) and greater LA wall stress (p = 0.001) than did those without. A stiff LA physiology was independently associated with DM [Odds ratio (OR) = 2.39, 95% confidence interval (CI) 1.02-5.59, p = 0.045], empirical extra-pulmonary vein LA ablation (OR = 3.14, 95% CI 1.07–9.3, p = 0.038) and the ΔPVR (OR = 1.78, 95% CI 1.37–2.31, p < 0.001). The ΔPVR was independently associated with DM (β = 0.37, 95% CI 0.06-0.67, p = 0.020) and a stiff LA physiology (β = 1.40, 95% CI 0.70–2.10, p < 0.001). During the 38.8 ± 29.3months follow-up, the incidence of the clinical recurrence of AF was significantly higher in the patients with a stiff LA physiology than in those without (log rank p = 0.032).

Conclusion

A stiff LA physiology was independently associated with DM because of the relatively small decrease in the PVR after AFCA in this population. The patients with a stiff LA physiology had worse rhythm outcomes after AFCA than those without.

Left Atrial Function Post Radiofrequency and Cryoballoon Ablation Assessed by Volume-Pressure Loops

Background

Left atrial (LA) function is linked to atrial fibrillation (AF) pathogenesis. AF catheter ablation decreases disease burden with potentially favorable effects on cardiac function. Atrial volume-pressure loops can optimally assess the LA function.

Objective

To investigate changes in LA function by volume-pressure loops after paroxysmal AF ablation and explored potential differences between the radiofrequency and cryoballoon ablation.

Methods

We analyzed 44 patients undergoing paroxysmal AF ablation from 2 centers, 22 treated with radiofrequency and 22 with cryoablation. Pre- and post-procedure, all patients underwent a real-time three-dimensional transthoracic ECG to evaluate LA volume, while simultaneously recording LA pressure following transseptal puncture. Volume-pressure loops pre- and post-procedure were created by paired data. Areas of A-loop (LA booster pump function) and V-loop (LA reservoir function), and the stiffness constant determining the slope of the exponential curve during LA filling were calculated.

Results

Average LA pressure, A-wave amplitude, and V-wave amplitude were increased post-procedurally (p < 0.001). Overall, A-loop area decreased (p = 0.001) and V-loop area tended to increase (p = 0.07). The change in both A-loop and V-loop areas was similar between radiofrequency- and cryoballoon-treated patients (p = 0.18 and p = 0.52, respectively). However, compared with cryoballoon-treated patients, radiofrequency-treated patients had higher increase in the stiffness constant (b = 0.059; 95% CI: 0.022–0.096; p = 0.006).

Conclusion

AF catheter ablation by the radiofrequency or cryoballoon is associated with the decrease of the booster pump function and increase of the reservoir function. Moreover, there is a post-procedural increase of LA pressure which is associated with an acute increase in LA stiffness in radiofrequency ablation, but not in cryoablation.

Echocardiographic Assessment of Atrial Function: From Basic Mechanics to Specific Cardiac Diseases

The left and right atria serve as buffer chambers to control the flow of venous blood for ventricular filling. If an atrium is absent, blood does not flow effectively into the ventricle, leading to venous blood retention and low cardiac output. The importance of atrial function has become increasingly recognized, because left atrial (LA) function contributes to cardiac performance, and loss of LA function is associated with heart failure. LA volume change has been used for LA function assessment in experimental and clinical studies. In conjunction with LA pressure, the LA pressure–volume relationship provides a better understanding of LA mechanics. LA strain measurement by speckle tracking echocardiography was introduced to evaluate three components of LA function as a (booster) pump, reservoir and conduit. Furthermore, increasing evidence supports the theory that LA reservoir strain has prognostic utility in various cardiac diseases. In this review, we summarize LA contribution to maintain cardiac performance by evaluating LA function with echocardiography according to our experiences and previous reports. Furthermore, we discuss LA dysfunction in challenging cardiac diseases of cardiac amyloidosis and adult congenital heart disease.

Stiff Left Atrium Syndrome After Atrial Fibrillation Ablation – A Diagnosis Not To Forget

Atrial fibrillation is the most prevalent arrhythmia in clinical practice and has different strategies for its control. Of these strategies, the percutaneous ablation of the pulmonary veins stands out, with robust results in relation to drug treatment. It is an invasive procedure and, therefore, not free from complications, which must be properly diagnosed and treated. Among the possible complications, there is stiff atrium syndrome, characterized by reduced atrial compliance caused by post-ablation fibrosis, which, in turn, leads to atrial filling dysfunction and the consequent increase in atrial and venous capillary pulmonary pressures. The case report demonstrates this infrequent but important complication, which presents good results for clinical treatment, in addition to the contribution of cardiac magnetic resonance in its diagnosis and in the assessment of arrhythmia recurrence rates.

Acute myocardial injury after radiofrequency catheter ablation: impact on pulmonary vein reconnection and relevant factors

Radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) causes myocardial injury and induces high-sensitive cardiac troponin I (hs-TnI) release into the systemic circulation. Several factors are considered to be associated with myocardial injury after ablation, but few studies showed the relationship between the value of myocardial injury marker after the RFCA and relevant factors. AF patients who underwent primary RFCA were enrolled from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry. The relationship between hs-TnI after the RFCA and PV reconnection (PVR) was evaluated. The impact of relevant factors, including baseline patient characteristics, detail of procedure on myocardial injury was investigated. This study included 407 patients (median age was 71 years, the ratio of female was 30.7%). Late arrhythmia recurrence was observed in 111 patients (27.3%) and 66 patients were underwent repeated ablation. PVR was observed in 33 patients (50.0%). The hs-TnI level was significantly lower in the patients with PVR than those without PVR (1.150 ng/ml vs 1.921 ng/ml, p = 0.040). Paroxysmal AF and age were significantly associated with acute myocardial injury after the RFCA (standardized beta coefficient = 0.206 and p < 0.001, standardized beta coefficient = - 0.114 and p = 0.043, respectively). The hs-TnI after RFCA was significantly higher in PAF patients than PerAF (p < 0.001), even if application number and total application time were taken into consideration. Acute myocardial injury after RFCA was significantly lower in the patients with PVR than those without PVR. Age and AF type were significantly and strongly associated with acute myocardial injury after the RFCA.

Risk Factors for Stiff Left Atrial Physiology 1 Year After Catheter Ablation of Atrial Fibrillation

Catheter ablation is the most effective rhythm control method for patients with atrial fibrillation (AF); however, it inevitably causes atrial tissue damage. We previously reported that AF catheter ablation (AFCA) increases left atrial (LA) pressure without changes in symptom scores. We hypothesized that extensive LA ablation increased the risk of stiff LA physiology. We included 1,720 patients (69.1% male, 60.0 [53.0-68.0] years old, 66.2% with paroxysmal AF) who underwent de novo AFCA and echocardiography before and 1-year after the procedure. Stiff LA physiology was defined, when the amount of the estimated pulmonary arterial pressure increase between the pre-procedural and the 1-year post-procedural follow-up echocardiography was >10 mmHg and when right ventricular systolic pressure (RVSP) was >35 mmHg at 1-year follow-up echocardiography. The failed rhythm control within 1 year was defined as recurrent AF despite using anti-arrhythmic drugs or cardioversion within a year of AFCA. We explored the incidence and risk factors for stiff LA physiology and the rhythm outcome of AFCA. Among the 1,720 patients, 64 (3.7%) had stiff LA physiology 1 year after AFCA. Stiff LA physiology was independently associated with diabetes (odds ratio [OR], 2.36 [95% CI, 1.14-4.87], p = 0.020), the ratio of the peak mitral flow velocity of the early rapid filling to the early diastolic velocity of the mitral annulus (E/Em; OR, 1.04 [95% CI, 1.00-1.10], p = 0.049), LA pulse pressure (Model 2: OR, 1.05 [95% CI, 1.00-1.11], p = 0.049), low LA voltage (OR, 0.36 [95% CI, 0.18-0.74], p = 0.005), empirical extra-pulmonary vein (PV) LA ablation (OR, 2.60 [95% CI, 1.17-5.74], p = 0.018), and radiofrequency (RF) ablation duration (Model 2: OR, 1.02 [95% CI, 1.01-1.03], p = 0.003). Although the incidence of post-AFCA stiff LA physiology was 3.7% and most of the cases were subclinical, the empirical extra-PV ablation was associated with this undesirable condition. In addition, patients who had low mean LA voltage before AFCA could be susceptible to stiff LA physiology.

Post-ablation left atrial function impacts long-term recurrence of atrial fibrillation after ablation

Left atrial (LA) function can help predict various cardiovascular events. Catheter ablation for atrial fibrillation (AF) modifies baseline LA function through the maintenance of sinus rhythm and myocardial injury. We investigated the impact of post-ablation LA function on recurrence of AF after ablation and identified the predictors of reduced post-ablation LA function. A total of 616 patients who underwent AF ablation (paroxysmal, N = 310; non-paroxysmal, N = 306) were retrospectively examined with cardiac computed tomography at baseline and 3 months after the final ablation procedure. Post-ablation LA emptying fraction (LAEF_post) was calculated. We evaluated the association between LAEF_post and recurrence of AF after the final ablation procedure. Further, we assessed the predictors of reduced LAEF_post. The recurrence rate of AF was 72.7% after the final ablation procedure [median follow-up 48 months (48.0, 48.0), total number of ablation sessions: 1.4 ± 0.7]. Multivariate analysis revealed that LAEF_post was associated with the recurrence of AF (hazard ratio/10% increase: 0.62, 95% confidence interval: 0.51-0.75, P < 0.0001). LAEF_post had a mild predictive power for recurrence of AF (c-statistics: 0.670, optimal cutoff: 26.36%, P < 0.0001). The recurrence-free proportion among patients with reduced LAEF_post (< 26.36%, N = 100) and those with preserved LAEF_post (≥ 26.36%, N = 516) was 40% and 79%, respectively (P < 0.0001). The predictors of reduced LAEF_post were low pre-ablation LAEF, high pre-ablation LA volume, low body mass index (BMI), and female sex. Further, reduced LAEF_post was associated with the total number of ablation sessions and extra-pulmonary vein LA ablation. In conclusion, reduced LAEF_post was associated with recurrence of AF after ablation. Advanced LA remodeling, low BMI, and female sex could predict reduced LAEF_post. Although additional ablation was associated with reduced LAEF_post, it remains unclear whether reduced LAEF_post resulted from the additional ablation. Reduced LAEF_post might help stratify patients with ablation-refractory AF.

Pulsed field ablation prevents chronic atrial fibrotic changes and restrictive mechanics after catheter ablation for atrial fibrillation

Aims

Pulsed field ablation (PFA), a non-thermal ablative modality, may show different effects on the myocardial tissue compared to thermal ablation. Thus, this study aimed to compare the left atrial (LA) structural and mechanical characteristics after PFA vs. thermal ablation.

Methods and results

Cardiac magnetic resonance was performed pre-ablation, acutely (<3 h), and 3 months post-ablation in 41 patients with paroxysmal atrial fibrillation (AF) undergoing pulmonary vein (PV) isolation with PFA (n = 18) or thermal ablation (n = 23, 16 radiofrequency ablations, 7 cryoablations). Late gadolinium enhancement (LGE), T2-weighted, and cine images were analysed. In the acute stage, LGE volume was 60% larger after PFA vs. thermal ablation (P < 0.001), and oedema on T2 imaging was 20% smaller (P = 0.002). Tissue changes were more homogeneous after PFA than after thermal ablation, with no sign of microvascular damage or intramural haemorrhage. In the chronic stage, the majority of acute LGE had disappeared after PFA, whereas most LGE persisted after thermal ablation. The maximum strain on PV antra, the LA expansion index, and LA active emptying fraction declined acutely after both PFA and thermal ablation but recovered at the chronic stage only with PFA.

Conclusion

Pulsed field ablation induces large acute LGE without microvascular damage or intramural haemorrhage. Most LGE lesions disappear in the chronic stage, suggesting a specific reparative process involving less chronic fibrosis. This process may contribute to a preserved tissue compliance and LA reservoir and booster pump functions.

Pulsed field ablation: a promise that came true

PURPOSE OF REVIEW

Pulsed field ablation is a nonthermal ablative modality that uses short living, strong electrical field created around catheter to create microscopic pores in cell membranes (electroporation). When adequately dosed/configured it shows a preference for myocardial tissue necrosis. Thus, it holds a promise to become a 'perfect' energy source for cardiac ablation to treat arrhythmias. Herein, we present update on platforms in clinical development.

RECENT FINDINGS

First in human series using pulsed field ablation for atrial fibrillation ablation have been completed and data published for several platforms. Acute safety outcomes are similar across the platforms with exceptionally low rate of those complications that are typically reported for thermal ablation methods (esophageal injury, pulmonary vein stenosis, phrenic nerve palsy). Promising acute data on pulmonary vein isolation had been corroborated with satisfactory 1-year clinical follow-up for a single platform, whereas reports are pending for the rest. Research efforts are being expanded to a development of focal catheters, and therefore, pulsed field ablation application for ventricular arrhythmias.

SUMMARY

As the reports confirming its safety and efficacy build up, there seems to be no way that the promise of pulsed field ablation could end in a blind alley.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Novel approaches to mechanism-based atrial fibrillation ablation

Modern cardiac electrophysiology has reported significant advances in the understanding of mechanisms underlying complex wave propagation patterns during atrial fibrillation (AF), although disagreements remain. One school of thought adheres to the long-held postulate that AF is the result of randomly propagating wavelets that wonder throughout the atria. Another school supports the notion that AF is deterministic in that it depends on a small number of high-frequency rotors generating three-dimensional scroll waves that propagate throughout the atria. The spiralling waves are thought to interact with anatomic and functional obstacles, leading to fragmentation and new wavelet formation associated with the irregular activation patterns documented on AF tracings. The deterministic hypothesis is consistent with demonstrable hierarchical gradients of activation frequency and AF termination on ablation at specific (non-random) atrial regions. During the last decade, data from realistic animal models and pilot clinical series have triggered a new era of novel methodologies to identify and ablate AF drivers outside the pulmonary veins. New generation electroanatomical mapping systems and multielectrode mapping catheters, complimented by powerful mathematical analyses, have generated the necessary platforms and tools for moving these approaches into clinical procedures. Recent clinical data using such platforms have provided encouraging evidence supporting the feasibility of targeting and effectively ablating driver regions in addition to pulmonary vein isolation in persistent AF. Here, we review state-of-the-art technologies and provide a comprehensive historical perspective, characterization, classification, and expected outcomes of current mechanism-based methods for AF ablation. We discuss also the challenges and expected future directions that scientists and clinicians will face in their efforts to understand AF dynamics and successfully implement any novel method into regular clinical practice.

Barriers and financial impact of same-day discharge after atrial fibrillation ablation

BACKGROUND

Same-day discharge (SDD) after atrial fibrillation (AF) ablation is increasingly being considered. This study examined the barriers and financial impact associated with SDD in a contemporary cohort of patients undergoing elective AF ablation.

METHODS

A single center retrospective review was conducted of the 249 first case-of-the-day outpatient AF ablations performed in 2019 to evaluate the proportion of patients that could have undergone SDD. Barriers to SDD were defined as any intervention that prevented SDD by 8 p.m. The financial impact of SDD was based on savings from avoidance of the overnight hospital stay and revenue related to management of chest pain facilitated by a vacant hospital bed.

RESULTS

SDD could have occurred in 157 patients (63%) without change in management and in up to 200 patients (80%) if avoidable barriers were addressed. Barriers to SDD included non-clinical logistical issues (43%), prolonged post-procedure recovery (42%) and minor procedural complications (15%). On multivariate analysis, factors associated with barriers to SDD included increasing age (P = .01), left ventricular ejection fraction ≤ 35% (P = .04), and severely dilated left atrium (P = .04). The financial gain from SDD would have ranged from $1,110,096 (assuming discharge of 63% of eligible patients) to $1,480,128 (assuming 80% discharge) over the course of a year.

CONCLUSIONS

Up to 80% of patients undergoing outpatient AF ablation were amenable to SDD if avoidable delays in care had been anticipated. Based on reduced hospital operating expenses and increased revenue from management of individuals with chest pain, this would translate to a financial savings of ∼$1.5 million.

Ablation Versus Drug Therapy for Atrial Fibrillation in Heart Failure: Results From the CABANA Trial

BACKGROUND

In patients with heart failure and atrial fibrillation (AF), several clinical trials have reported improved outcomes, including freedom from AF recurrence, quality of life, and survival, with catheter ablation. This article describes the treatment-related outcomes of the AF patients with heart failure enrolled in the CABANA trial (Catheter Ablation Versus Antiarrhythmic Drug Therapy for Atrial Fibrillation).

METHODS

The CABANA trial randomized 2204 patients with AF who were ≥65 years old or <65 years old with ≥1 risk factor for stroke at 126 sites to ablation with pulmonary vein isolation or drug therapy including rate or rhythm control drugs. Of these, 778 (35%) had New York Heart Association class >II at baseline and form the subject of this article. The CABANA trial's primary end point was a composite of death, disabling stroke, serious bleeding, or cardiac arrest.

RESULTS

Of the 778 patients with heart failure enrolled in CABANA, 378 were assigned to ablation and 400 to drug therapy. Ejection fraction at baseline was available for 571 patients (73.0%), and 9.3% of these had an ejection fraction <40%, whereas 11.7% had ejection fractions between 40% and 50%. In the intention-to-treat analysis, the ablation arm had a 36% relative reduction in the primary composite end point (hazard ratio, 0.64 [95% CI, 0.41-0.99]) and a 43% relative reduction in all-cause mortality (hazard ratio, 0.57 [95% CI, 0.33-0.96]) compared with drug therapy alone over a median follow-up of 48.5 months. AF recurrence was decreased with ablation (hazard ratio, 0.56 [95% CI, 0.42-0.74]). The adjusted mean difference for the AFEQT (Atrial Fibrillation Effect on Quality of Life) summary score averaged over the entire 60-month follow-up was 5.0 points, favoring the ablation arm (95% CI, 2.5-7.4 points), and the MAFSI (Mayo Atrial Fibrillation-Specific Symptom Inventory) frequency score difference was -2.0 points, favoring ablation (95% CI, -2.9 to -1.2).

CONCLUSIONS

In patients with AF enrolled in the CABANA trial who had clinically diagnosed stable heart failure at trial entry, catheter ablation produced clinically important improvements in survival, freedom from AF recurrence, and quality of life relative to drug therapy. These results, obtained in a cohort most of whom had preserved left ventricular function, require independent trial verification. Registration: URL: https://www.clinicaltrials.gov/ct2/show/NCT00911508; Unique identifier: NCT0091150.

Anatomical targets and expected outcomes of catheter-based ablation of atrial fibrillation in 2020

Anatomical-based approaches, targeting either pulmonary vein isolation (PVI) or additional extra PV regions, represent the most commonly used ablation treatments in symptomatic patients with atrial fibrillation (AF) recurrences despite antiarrhythmic drug therapy. PVI remains the main anatomical target during catheter-based AF ablation, with the aid of new technological advances as contact force monitoring to increase safety and effective radiofrequency (RF) lesions. Nowadays, cryoballoon ablation has also achieved the same level of scientific evidence in patients with paroxysmal AF undergoing PVI. In parallel, electrical isolation of extra PV targets has progressively increased, which is associated with a steady increase in complex cases undergoing ablation. Several atrial regions as the left atrial posterior wall, the vein of Marshall, the left atrial appendage, or the coronary sinus have been described in different series as locations potentially involved in AF initiation and maintenance. Targeting these regions may be challenging using conventional point-by-point RF delivery, which has opened new opportunities for coadjuvant alternatives as balloon ablation or selective ethanol injection. Although more extensive ablation may increase intraprocedural AF termination and freedom from arrhythmias during the follow-up, some of the targets to achieve such outcomes are not exempt of potential severe complications. Here, we review and discuss current anatomical approaches and the main ablation technologies to target atrial regions associated with AF initiation and maintenance.

Atrial appendages’ mechanics assessed by 3D transoesophageal echocardiography as predictors of atrial fibrillation recurrence after pulmonary vein isolation

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Data on atrial appendages' mechanics as predictors of AF recurrence after PVI is scarce.

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3D and 2D-TEE have potential to provide additional data on LAA function.

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Patients with AFR had significantly lower LAA tissue velocity and ostium surface area.

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RAA tissue velocity and SVC ostium surface area were not correlated to AF recurrence.

Background

Although there are numerous studies reflecting predictors of atrial fibrillation (AF) recurrence (AFR) after pulmonary vein isolation (PVI), data on atrial appendages' mechanics is scarce. This study aimed to assess atrial appendages' mechanics by 2-dimensional (2D) and 3-dimenssional (3D) transoesphageal echocardiography (TEE) and to explore its value to predict AFR after PVI.

Methods

Consecutive patients with paroxysmal AF undergoing first PVIwere analysed. 3D and 2D-TEE with tissue Doppler imaging (TDI) and strain analysis was obtained prior to the PVI, including: left atrial appendage (LAA) TDI and strain analysis, LAA ostium surface area, right atrial appendage’s TDI velocity and superior vena cava (SVC) ostium surface area. The primary end-point was freedom from any documented recurrence of atrial arrhythmia lasting > 30 s.

Results

This single-centre, prospective study included 74 patients with paroxysmal AF (median age 59 years; 36% female; BMI 27.4 ± 4.1 kg/m², LA volume index 32 ± 11 mL/m²). After a median follow-up of 14 (IQR 10–22) months, 21 (28%) patients had AFR. In a univariate and multivariate Cox-regression analysis LAA TDI velocity (HR 1.48, 95%CI 1.28–1.62, p < 0.001) and LAA ostium surface area(HR 1.58, 95%CI 1.06–1.81, p = 0.033) both independently predicted AFR after single PVI. RAA TDI velocity and SVC ostium surface area were not correlated to AFR.

Conclusion

Paroxysmal AF patients with lower LAA TDI tissue velocity and LAA ostium surface area have higher risk of developing AFR after PVI. To our knowledge, this is the first study assessing atrial appendages’ mechanics in predicting AFR after PVI.

Clinical trial registration: www.drks.de(Identifier: DRKS00010495)

Higher Pulmonary Arterial Pressure Was Related to Non-Pulmonary Vein Atrial Tachyarrhythmia

Recurrence of atrial tachyarrhythmias (ATA) following catheter ablation for atrial fibrillation (AF) is often associated with the recovery of conduction into previously isolated pulmonary veins (PVs). Little evidence concerning repeat PV isolation (PVI) and non-PV ATA ablation has been reported. This study aimed to explore the clinical outcome of recurrent ATA ablation after PVI and the difference between patients with and without non-PV ATA.A total of 49 patients without structural heart diseases who received catheter ablation for recurrent AF between January 2014 and December 2018 were recruited (prior ablation with PVI only 71.4% and PVI with cavotricuspid isthmus line ablation 28.6%). Patients were divided into two groups according to the presence or absence of non-PV ATA.Most patients (53.1%) experienced very late recurrence with a median duration of 15 months. A total of 15 patients had non-PV ATA and received non-PV ATA ablation whereas 34 patients received only repeat PVI for reconnected PVs. A higher pulmonary arterial systolic pressure (PASP) was associated with non-PV ATA (odds ratio: 1.161; 95% confidence interval: 1.021-1.321; P = 0.023). During 4.7 ± 1 months, 4/15 (26.7%) and 1/34 (2.9%) patients with and without non-PV ATA, respectively, had ATA recurrence (P = 0.011). The cumulative incidence of ATA recurrence after repeat ablation was significantly lower in patients without non-PV ATA (P = 0.013).In our study, a high PASP was associated with non-PV ATA in patients with recurrent AF. Repeat PVI had a high rate of maintenance of sinus rhythm in patients without non-PV ATA.