2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: Executive summary

Clinical Utility of Synthesized 18-Lead Electrocardiography

Eighteen-lead electrocardiography (18-ECG) includes, in addition to those in standard 12-lead ECG (12-ECG), six additional chest leads: V7-V9 and V3RV5R. Leads V7-V9 require the patient to be in a lateral decubitus position for the electrodes to be attached to the back. Synthesized 18-ECG (syn18-ECG) is a method that only records 12-ECG and uses computational logic to record the posterior wall (V7-V9) and right-sided (V3R-V5R) leads. We review the clinical utility of syn18-ECG in conditions including acute coronary syndromes, arrhythmias, acute pulmonary embolism, and Duchenne muscular dystrophy. The syn18-ECG waveform correlates well with the actual 18-ECG waveform, indicating that syn18-ECG is an excellent substitute for 18-ECG, excluding negative T waves. ST elevation in leads V7-V9 has the effect of reducing missed acute coronary syndromes in the posterior wall. In cases of arrhythmia, syn18-ECG can accurately estimate the target site of radiofrequency catheter ablation using a simple algorithm. The use of additional leads in Duchenne muscular dystrophy is expected to provide new insights. To facilitate gaining more knowledge regarding diseases that have not yet been investigated, it is imperative that the cost of syn18-ECG is reduced in the future.

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.

Long-term outcomes of catheter ablation for atrial fibrillation in octogenarians

BACKGROUND AND AIMS

Catheter ablation is superior to pharmacological therapy in controlling atrial fibrillation (AF). There are few data on the long-term outcome of AF ablation in octogenarian patients. This analysis aims to evaluate the outcome of AF ablation in octogenarians vs. younger patients.

METHODS

In this retrospective study in 13 centres in the UK, France, and Switzerland, the long-term outcomes of 473 consecutive octogenarian patients undergoing ablation for AF were compared to 473 matched younger controls (median age 81.3 [80.0, 83.0] vs. 64.4 [56.5, 70.7] years, 54.3% vs. 35.1% females; p-value for both < 0.001). The primary endpoint was the recurrence of atrial arrhythmia after a blanking period of 90 days within 365 days of follow-up.

RESULTS

Acute ablation success as defined as isolation of all pulmonary veins was achieved in 97% of octogenarians. Octogenarians experienced more procedural complications (11.4% vs 7.0%, p = 0.018). The median follow-up time was 281 [106, 365] days vs. 354 [220, 365] days for octogenarians vs. non-octogenarians (p < 0.001). Among octogenarians, 27.7% (131 patients) experienced a recurrence of atrial arrhythmia, in contrast to 23.5% (111 patients) in the younger group (odds ratio 1.49; 95% confidence interval 1.16-1.92; p = 0.002). In a multivariable regression model including gender, previous AF ablation, vascular disease, chronic kidney disease, CHA2DS2-VASc score, left atrial dilatation, and indwelling cardiac implantable electronic device, age above 80 remained an independent predictor of recurrence of arrhythmia.

CONCLUSION

Ablation for AF is effective in octogenarians, but is associated with slightly higher procedural complication rate and recurrence of atrial arrhythmia than in younger patients.

Radiofrequency ablation-Real-time visualization of lesions and their correlation with underlying parameters

BACKGROUND

Lesion durability and transmurality are crucial for successful radiofrequency (RF) ablation. This study provides a model of real-time RF lesion visualization and insights into the role of underlying parameters, as local impedance (LI).

METHODS

A force-sensing, LI-sensing catheter was used for lesion creation in an ex vivo model involving cross-sections of porcine cardiac preparations. During 60 s of RF application, one measurement per second was performed regarding lesion size and available ablation parameters. In total, 1847 measurements from n = 36 lesions were performed. Power (20-50 W) and contact force (1-5 g, 10-15 g, 20-25 g) were systematically alternated.

RESULTS

Lesion formation was most prominent in the first seconds of RF application during which nonlinear lesion growth was observed (max. 1.08 mm/s for lesion depth and 2.71 mm/s for lesion diameter). Power levels determined the extent of lesion formation in the early phase. After 20 s, lesion size growth velocity approaches 0.1 mm/s at all power levels. LI changes were also highest in the first seconds (up to - 12 Ω/s) and decreased to less than - 0.1Ω/s after prolonged application.

CONCLUSION

Lesion formation in irrigated RF ablation is a nonlinear process. Final lesion size resulting from an RF application is mainly influenced by high rates of lesion growth in the first seconds of ablation. LI seems to be a good surrogate for differentiating changes in lesion formation.

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.

Surgical ablation of atrial fibrillation is associated with improved survival compared with appendage obliteration alone: An analysis of 100,000 Medicare beneficiaries

OBJECTIVE

Societal guidelines support the concomitant surgical ablation of atrial fibrillation in patients undergoing cardiac surgery. Recent evidence has highlighted the stroke reduction of left atrial appendage obliteration with or without surgical ablation in similar populations. To inform clinical decision-making, we evaluated real-world outcomes of patients with atrial fibrillation undergoing cardiac surgery by comparing no atrial fibrillation management with left atrial appendage obliteration alone versus surgical ablation + left atrial appendage obliteration.

METHODS

By using the US Centers for Medicare and Medicaid Services inpatient claims database, we evaluated all beneficiaries aged 65 years and older with a diagnosis of atrial fibrillation undergoing coronary artery bypass grafting or mitral/aortic/tricuspid valve repair or replacement between January 2018 and December 2020. Diagnosis-related group and International Classification of Diseases, 10th Revision procedure codes were used to define variables. Risk adjustment was performed with regression analysis using inverse probability weighting of propensity scores and Cox proportional hazards models. Subgroup analyses stratified patients by primary operation and paroxysmal or persistent atrial fibrillation.

RESULTS

A total of 103,382 patients with preoperative atrial fibrillation were stratified by surgical ablation + left atrial appendage obliteration (10,437; 10.1%), left atrial appendage obliteration alone (12,901; 12.5%), or no atrial fibrillation management (80,044; 77.4%). Patients with persistent atrial fibrillation (21,076; 20.4%) received the highest proportion of surgical ablation + left atrial appendage obliteration (4661 19.4%) and left atrial appendage obliteration alone (3%724%; 15.4%) versus no atrial fibrillation management (15,688; 65.2%). Likewise, patients undergoing open atrial operations (mitral/tricuspid; 17,204; 16.6%) had higher proportions of atrial fibrillation treatment (surgical ablation + left atrial appendage obliteration 5267 30.6%; left atrial appendage obliteration alone 4259 24.8%; no atrial fibrillation management 7678 44.6%). After robust risk adjustment, surgical ablation + left atrial appendage obliteration was independently associated with reduced 3-year mortality compared with no atrial fibrillation treatment (hazard ratio, 0.68, P < .001) and left atrial appendage obliteration alone (hazard ratio, 0.90, P < .001). Compared with no atrial fibrillation treatment, readmissions for embolic stroke were lower with both surgical ablation + left atrial appendage obliteration (hazard ratio, 0.77, P = .009) and left atrial appendage obliteration alone (hazard ratio, 0.73, P < .001). Reduction in 3-year composite mortality or stroke after surgical ablation + left atrial appendage obliteration was superior to left atrial appendage alone (hazard ratio, 0.90, P = .035).

CONCLUSIONS

In Medicare beneficiaries with atrial fibrillation undergoing cardiac surgery, the surgical management of atrial fibrillation was associated with lower 3-year mortality and readmission for stroke, with surgical ablation + left atrial appendage obliteration being associated with higher survival compared with left atrial appendage obliteration alone.

Transoesophageal echocardiography beyond the echo-laboratory. An expert consensus paper of the working group of echocardiography of the hellenic society of cardiology

Transoesophageal echocardiography (TOE) is a well-established and valid imaging modality, providing more accurate and of higher quality information than transthoracic echocardiography (TTE) for several specific diagnoses and recently a useful guide of an increasing number of catheter-based and surgical interventions. The present paper represents an effort by the Echocardiography Working Group (WG) of the Hellenic Society of Cardiology to state the essential steps of the TOE exam performed beyond the echo lab: a) in the operating rooms intraoperatively during either transcatheter interventions, or cardiothoracic surgery and b) in the intensive care unit for critically ill patients' monitoring. This paper includes information and tips and tricks about the pre-procedural evaluation, the procedural echocardiographic guidance, and post-procedural evaluation of the result and potential complications.

Mechanisms of action behind the protective effects of proactive esophageal cooling during radiofrequency catheter ablation in the left atrium

Proactive esophageal cooling for the purpose of reducing the likelihood of ablation-related esophageal injury resulting from radiofrequency (RF) cardiac ablation procedures is increasingly being used and has been Food and Drug Administration cleared as a protective strategy during left atrial RF ablation for the treatment of atrial fibrillation. In this review, we examine the evidence supporting the use of proactive esophageal cooling and the potential mechanisms of action that reduce the likelihood of atrioesophageal fistula (AEF) formation. Although the pathophysiology behind AEF formation after thermal injury from RF ablation is not well studied, a robust literature on fistula formation in other conditions (eg, Crohn disease, cancer, and trauma) exists and the relationship to AEF formation is investigated in this review. Likewise, we examine the abundant data in the surgical literature on burn and thermal injury progression as well as the acute and chronic mitigating effects of cooling. We discuss the relationship of these data and maladaptive healing mechanisms to the well-recognized postablation pathophysiological effects after RF ablation. Finally, we review additional important considerations such as patient selection, clinical workflow, and implementation strategies for proactive esophageal cooling.

Predictors of systolic function recovery after atrial fibrillation ablation in heart failure patients

INTRODUCTION AND OBJECTIVES

Atrial fibrillation (AF) and heart failure (HF) often coexist. AF catheter ablation improves left ventricular ejection fraction (LVEF), but its impact varies between patients. We aimed to identify predictors of LVEF improvement in HF patients with impaired LVEF undergoing AF ablation.

METHODS

We conducted a retrospective single-center study in HF patients with LVEF <50% undergoing AF catheter ablation between May 2016 and May 2022. The primary endpoint was the LVEF recovery rate ('responders'). Secondary endpoints were one-year safety and effectiveness. We also aimed to validate a prediction model for LVEF recovery.

RESULTS

The study included 100 patients (79% male, median age 60 years, 70% with probable tachycardia-induced cardiomyopathy [TIC], mean LVEF 37%, 29% with paroxysmal AF). After a median follow-up of 12 months after catheter ablation, LVEF improved significantly (36±10% vs. 53±10%, p<0.001), with an 82% responder rate. A suspected diagnosis of TIC (OR 4.916 [95% CI 1.166-20.732], p=0.030), shorter QRS duration (OR 0.969 [95% CI 0.945-0.994], p=0.015), and smaller left ventricle (OR 0.893 [95% CI 0.799-0.999], p=0.049) were independently associated with LVEF improvement. Freedom from any documented atrial arrhythmia was 86% (64% under antiarrhythmic drugs), and the rate of adverse events was 2%. The prediction model had a good discriminative performance (AUC 0.814 [95% CI 0.681-0.947]).

CONCLUSION

In AF patients with HF and impaired LVEF, suspected TIC, shorter QRS duration, and smaller LV diameter were associated with LVEF recovery following AF catheter ablation.

Accuracy of symptoms and pulse checking for detecting atrial fibrillation following catheter ablation

BACKGROUND

There is growing interest in the possibility of discontinuing oral anticoagulation following successful catheter ablation of atrial fibrillation (AF). However, it remains unknown whether patients can accurately detect arrhythmia recurrences following ablation. We therefore sought to characterize the accuracy of pulse checking and arrhythmia symptoms for the identification of AF following ablation.

METHODS

This prospective cohort study included patients at the Hospital of the University of Pennsylvania with an insertable cardiac monitor (ICM) treated with catheter ablation for AF who recorded the results from minimum twice daily pulse checks and additionally with arrhythmia symptoms into a diary for 2 months following their procedure. Accuracy of this self-assessment protocol was determined by comparison to ICM-detected AF.

RESULTS

A total of 55 patients (age 69 ± 8 years, 30 (55%) male, CHA2DS2VASc score 3.2 ± 1. 5) were included. Patients recorded a total of 5911 pulse checks, and there were 280 episodes of ICM-documented AF among 26 patients with an average duration of 2.5 ± 3.3 h. Among 362 episodes of patient-suspected AF, 134 correlated with ICM-identified AF (37% true positive rate). Of the 5549 pulse checks that did not identify AF, 196 correlated with ICM-identified AF (4% false negative rate). Twice daily pulse checking had a sensitivity of 47% and a specificity of 96% for identifying each episode of AF.

CONCLUSIONS

Our data indicate that a strategy of pulse checks and symptom assessment is insufficient to identify all episodes of AF in many patients following catheter ablation.

Borg's exertion scale did not coincide with ventilatory anaerobic threshold in atrial fibrillation patients with restored sinus rhythm after ablation

The determination of precise exercise intensity is essential for effective exercise rehabilitation. The Borg rating of perceived exertion category ratio (CR) scale is utilized to prescribe an appropriate level of exertion intensity. A Borg CR of approximately 13 coincides with the ventilatory aerobic threshold (VAT). Patients with atrial fibrillation (AF) exhibit various symptoms. We hypothesized that the workload at Borg CR13 (Borg CR13-Watt) differs from the workload at the VAT level (VAT-Watt) in AF patients with restored sinus rhythm (SR) following ablation. Accordingly, the relationship between Borg CR13-Watt and VAT-Watt was studied in patients with restored SR. Cardiopulmonary exercise testing (CPET) was performed at 101±88 days after ablation in 150 patients using a bicycle ergometer. No adverse events were observed during CPET. Borg CR13-Watt was significantly higher than VAT-Watt (67.2±27.8 Watt vs. 54.7±17.6 Watt, P<0.0001). Borg CR13-Watt showed significant linear regression with VAT-Watt (regression coefficient, 0.49, P<0.01; correlation coefficient, 0.80, P<0.01). Higher Borg CR13-Watt was associated with greater differences between Borg CR13-Watt and VAT-Watt (ΔWatt). The Bland-Altman plot showed nonconcordance between the two. Male sex, use of antiarrhythmic drugs, and smoking had contributed to the increased ΔWatt. Duration from ablation to time of CPET did not correlate with ΔWatt. Therefore, Borg CR13-Watt did not coincide with VAT-Watt in patients with restored SR. Higher Borg CR13-Watt was associated with greater ΔWatt. Prescribing exertion intensity as determined solely by perceived exertion is inadequate. CPET is required to determine the precise exercise intensity in AF patients with restored SR after ablation.

Wound incidence and outcomes in atrial fibrillation: Comparing catheter ablation and anti-arrhythmic drug therapy

The most prevalent form of cardiac arrhythmia is atrial fibrillation (AF), which is typically managed through catheter ablation or anti-arrhythmic drug therapy. We compared the incidence and outcomes of wound complications in patients with atrial fibrillation who were treated with catheter ablation as opposed to anti-arrhythmic drug therapy. From May to November 2023, 240 adult AF patients who were treated with catheter ablation or anti-arrhythmic medications participated in a 6-month retrospective cohort study at Sir Run Run Shaw Hospital in Hangzhou, China. An observation was made regarding 29 wound complications out of 240 patients. In comparison to drug therapy group, incidence of minor (8 vs. 11) and total complications (18 vs. 11) was greater in catheter ablation group. Significant adverse events occurred at higher rate in the catheter ablation group (6 versus 1) (p < 0.05). However, despite these patterns, there was no statistically significant difference in the rates of complications (total: p = 0.245; minor: p = 0.217; major: p = 0.128). Comparable treatment efficacy was observed across groups. In contrast to drug therapy, catheter ablation was associated with decreased probability of complications (odds ratio: 0.86), as determined by logistic regression; cardiac failure was a significant predictor of adverse outcomes. The study concluded that the risks of wound complications associated with catheter ablation and anti-arrhythmic drug therapy in patients with atrial fibrillation are comparable. Notwithstanding an elevated propensity for complications in ablation group, the statistical analysis indicated comparable safety profiles.

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 .

Surgical options for atrial fibrillation treatment during concomitant cardiac procedures

Current guidelines recommend concomitant surgical ablation (SA) of atrial fibrillation (AF) in the context of mitral valve disease. A variety of energy sources have been tested for SA to perform effective transmural lesions reliably. To date, only radiofrequency and cryothermy energies are considered viable options. The gold standard for SA is the Cox-Maze ablation set, especially for non-paroxysmal AF (nPAF), with the aim of interrupting macro-reentrant drivers perpetuating AF, without hampering the sinus node activation of both atria, and to maintain the atrioventricular synchrony. Although the efficacy of SA in terms of early and late sinus rhythm restoration has been clearly demonstrated over the years, concomitant AF ablation is still underperformed in patients with AF undergoing cardiac surgery. From a surgical standpoint, concerns have been raised about whether a single (left) or double atriotomy would be justified in AF patients undergoing a "non-atriotomy" surgical procedure, such as aortic valve or revascularization surgery. Thus, an array of simplified lesion sets have been described in the last decade, which have unavoidably hampered procedural efficacy, somewhat jeopardizing the standardization process of ablation surgery. As a matter of fact, the term "Maze" has improperly become a generic term for SA. Surgical interventions that do not align with the principles of forming conduction-blocking lesions according to the Maze pattern, cannot be classified as Maze procedures. In this complex scenario, a tailored approach according to the different AF patterns has been proposed: for patients with concomitant nPAF, a biatrial Cox-Maze ablation is recommended. Conversely, it might be reasonable to limit lesions to the left atrium or the pulmonary veins in patients with paroxysmal AF (PAF) in some clinical scenarios. The aim of this review is to provide an overview of the current ablation strategies for patients with AF undergoing concomitant cardiac surgery.

Performance of a non-irrigated bipolar radiofrequency ablation clamp on beating human hearts

OBJECTIVE

This study is intended to examine the efficacy of a non-irrigated bipolar RF clamp and explore the factors that can influence its performance on beating human hearts using the electrophysiology mapping method.

METHODS

A total of 83 atrial fibrillation (AF) patients were included in this study. Based on the Body mass index (BMI, kg/m2), the AF patients were divided into the normal group (18.5 ≤ BMI < 25) and the overweight or obese group (BMI ≥ 25). They all underwent a stand-alone surgical ablation through our off-pump biatrial mini-maze procedure. After we completed each time of ablation, the achievement of PV isolation was checked using the electrophysiology mapping method. The number of ablation times to achieve the PV isolation on the left and right PVs was recorded respectively.

RESULTS

86.7% (72/83) PV isolation on the LPV and 72.3% (60/83) PV isolation on the RPV could be achieved respectively after performing a single time of surgical ablation. Three times of ablations resulted in 100.0% PV isolation on the left and right PVs. In the normal BMI group, the ratio of patients who achieved a complete PV isolation after a single time of ablation was 83.7% (36/43), which was higher than the 60.0% (24/40) in the overweight or obese group.

CONCLUSIONS

Performing three times of ablations resulted in 100% PV isolation on the left and right PVs. The bipolar RF clamp had a better performance on the LPV than on the RPV. The patients' BMI also influenced the Atricure clamp' s performance.

The effect of an initial catheter ablation with an adjunctive ethanol infusion into the vein of Marshall on persistent atrial fibrillation

INTRODUCTION

Some previous studies have reported that a first-step ethanol infusion into the vein of Marshall (EIVOM) with touch-up radiofrequency (RF) ablation can facilitate mitral isthmus (MI) block and improves the ablation outcomes in persistent atrial fibrillation (PeAF) patients. However, the effect of an initial RF ablation with an adjunctive EIVOM has not been fully investigated.

METHODS

This study enrolled 233 PeAF patients undergoing pulmonary vein isolation and linear ablation including an MI, roof line, and cavotricuspid isthmus ablation. An EIVOM was performed when endocardial ablation with or without coronary sinus ablation failed to create MI block.

RESULTS

Bidirectional MI block was achieved in 224 patients (96.1%). Among them, MI block was obtained by only RF ablation in 174/224 patients (77.7%) (RF group) and an adjunctive EIVOM was needed in 50/224 (22.3%) (EIVOM group). During the follow-up, 113 (64.9%) RF group patients were free from AF/atrial tachycardia compared to 41 (82.0%) EIVOM group patients (log-rank p = .045). In a multivariate Cox regression analysis, an adjunctive EIVOM was associated with a lower recurrence rate (hazard ratio = 0.39, 95% confidence interval = 0.17-0.78, p = .006).

CONCLUSION

An initial RF ablation with an adjunctive EIVOM strategy improved MI ablation's acute success rate and was associated with better clinical outcomes.

Incidence of cryoballoon expansion dislodgement during pulmonary vein isolation-An underappreciated frequent cause of incomplete isolation

BACKGROUND

Cryoballoon ablation for atrial fibrillation (AF) requires adequate contact between the pulmonary vein (PV) antrum and cryoballoon. The surge of intraballoon pressure during the initial phase of ablation may change the balloon's shape and compliance, resulting in balloon dislodgement and loss of PV occlusion. Without continuous monitoring, this phenomenon is often undetected but can be associated with incomplete PV isolation (PVI).

METHODS

Primary cryoablation of AF was performed in 15 patients. PV occlusion status pre- and post-freezing were analyzed with intracardiac echocardiography (ICE) and dielectric imaging-based occlusion tool (DIOT) to calculate the incidence of expansion dislodgement of cryoballoon.

RESULTS

A total of 105 cryoablation applications were performed on 57 veins, including three common ostiums of left pulmonary veins. In the evaluation of PV occlusion, both modalities reported consistent results in 86.7% of the assessments. Despite complete PV occlusion before ablation, peri-balloon leak after initiation of freezing was detected by ICE in 5/22 (22.7%) applications and by DIOT in 8/25 (32%) applications.

CONCLUSION

Incidence of expansion dislodgement of the cryoballoon was detected in one-fourth to one-third of cryoablation applications depending on the imaging modality used, which was clinically frequent and significant.

Combination of frequency- and time-domain characteristics of the fibrillatory waves for enhanced prediction of persistent atrial fibrillation recurrence after catheter ablation

Catheter ablation (CA) remains the cornerstone alternative to cardioversion for sinus rhythm (SR) restoration in patients with atrial fibrillation (AF). Unfortunately, despite the last methodological and technological advances, this procedure is not consistently effective in treating persistent AF. Beyond introducing new indices to characterize the fibrillatory waves (f-waves) recorded through the preoperative electrocardiogram (ECG), the aim of this study is to combine frequency- and time-domain features to improve CA outcome prediction and optimize patient selection for the procedure, given the absence of any study that jointly analyzes information from both domains. Precisely, the f-waves of 151 persistent AF patients undergoing their first CA procedure were extracted from standard V1 lead. Novel spectral and amplitude features were derived from these waves and combined through a machine learning algorithm to anticipate the intervention mid-term outcome. The power rate index (φ), which estimates the power of the harmonic content regarding the dominant frequency (DF), yielded the maximum individual discriminant ability of 64% to discern between individuals who experienced a recurrence of AF and those who sustained SR after a 9-month follow-up period. The predictive accuracy was improved up to 78.5% when this parameter φ was merged with the amplitude spectrum area in the DF bandwidth (A M S A L F ) and the normalized amplitude of the f-waves into a prediction model based on an ensemble classifier, built by random undersampling boosting of decision trees. This outcome suggests that the synthesis of both spectral and temporal features of the f-waves before CA might enrich the prognostic knowledge of this therapy for persistent AF patients.

The role of epicardial fat radiomic profiles for atrial fibrillation identification and recurrence risk with coronary CT angiography

OBJECTIVES

Fat radiomic profile (FRP) was a promising imaging biomarker for identifying increased cardiac risk. We hypothesize FRP can be extended to fat regions around pulmonary veins (PV), left atrium (LA), and left atrial appendage (LAA) to investigate their usefulness in identifying atrial fibrillation (AF) and the risk of AF recurrence.

METHODS

We analysed 300 individuals and grouped patients according to the occurrence and types of AF. We used receiver operating characteristic and survival curves analyses to evaluate the value of imaging biomarkers, including fat attenuation index (FAI) and FRP, in distinguishing AF from sinus rhythm and predicting post-ablation recurrence.

RESULTS

FRPs from AF-relevant fat regions showed significant performance in distinguishing AF and non-AF with higher AUC values than FAI (peri-PV: FRP = 0.961 vs FAI = 0.579, peri-LA: FRP = 0.923 vs FAI = 0.575, peri-LAA: FRP = 0.900 vs FAI = 0.665). FRPs from peri-PV, peri-LA, and peri-LAA were able to differentiate persistent and paroxysmal AF with AUC values of 0.804, 0.819, and 0.694. FRP from these regions improved AF recurrence prediction with an AUC of 0.929, 0.732, and 0.794. Patients with FRP cut-off values of ≥0.16, 0.38, and 0.26 had a 7.22-, 5.15-, and 4.25-fold higher risk of post-procedure recurrence, respectively.

CONCLUSIONS

FRP demonstrated potential in identifying AF, distinguishing AF types, and predicting AF recurrence risk after ablation. FRP from peri-PV fat depot exhibited a strong correlation with AF. Therefore, evaluating epicardial fat using FRP was a promising approach to enhance AF clinical management.

ADVANCES IN KNOWLEDGE

The role of epicardial adipose tissue (EAT) in AF had been confirmed, we focussed on the relationship between EAT around pulmonary arteries and LAA in AF which was still unknown. Meanwhile, we used the FRP to excavate more information of EAT in AF.

Comparison of the electrophysiological properties of the pulmonary veins between paroxysmal and persistent atrial fibrillation

Background

The role of the pulmonary veins (PVs) as triggers in atrial fibrillation (AF) is well-known; however, their detailed electrophysiological properties have not been thoroughly examined.

Objective

This study aimed to investigate the electrophysiological properties of the PVs between paroxysmal AF (pAF) and persistent AF (perAF).

Methods

Prior to catheter ablation in patients with pAF (n = 51) and perAF (n = 41), a voltage map of the left atrium and PVs was created under sinus rhythm, and the area of the myocardial sleeves in the PVs and their electrophysiological characteristics, including the pacing threshold and effective refractory period (ERP), were compared between the two groups.

Results

Compared with perAF, the myocardial sleeves of PVs for pAF were significantly larger for all PVs. The ERP for perAF was significantly shorter than that for pAF for all PVs. The pacing threshold for perAF was significantly higher than that for pAF for the right and left superior PVs.

Conclusion

In patients with perAF, a decrease in the normal myocardial sleeves and a shortening of the ERP were observed for all PVs. Those changes in the electrophysiological properties of the PVs might be related to the persistence of AF.

Experimental study of the bilateral asymmetric single-rivet occluder device for transcatheter patent foramen ovale closure with reserved interatrial septal puncture area

Purpose

To evaluate a noval bilateral asymmetric single-rivet occluder with reserved interatrial septal puncture area for treating patent foramen ovale (PFO).

Materials and methods

The study established a pig model of patent foramen ovale (PFO) by puncturing the oval fossa and then performing high-pressure balloon dilation. A specially designed bilateral asymmetric occluder for the reserved interatrial septal puncture area was then. used to close the PFO through catheter-based intervention. The pigs were kept for 3 months before undergoing a second catheter-based intervention, involving interatrial septal puncture using a newly developed occluder in the reserved interatrial septal puncture area. During 6 months, the experimental pigs underwent assessment using digital subtraction angiography (DSA), echocardiography, and histological evaluation.

Results

A patent foramen ovale (PFO) model was successfully established in 6 pigs using the puncture atrial septum high-pressure balloon dilation method. The diameter of the unclosed PFO was measured (3.56 ± 0.25 mm). Using the newly developed occluder device, all 6 pigs with unclosed PFO underwent successful catheter-based closure surgeries, with intraoperative and postoperative transesophageal echocardiography showing excellent device positioning and complete closure without residual shunting. After 3 months of implantation, the catheter-based interatrial septal puncture was performed through the reserved interatrial septal puncture area, and all procedures were successful. Immediately following euthanasia, a histological examination revealed intact and undamaged occluder devices with visible puncture holes in the reserved interatrial septal puncture area. No fracture of the nitinol wire was observed, and the surface of the occluder device showed coverage of endothelial and connective tissues. Utilizing a bilateral asymmetric single-rivet occluder device implanted through the reserved interatrial septal puncture area has proven effective in closing PFO. After implantation, the occluder device allows subsequent interatrial septal puncture procedures through the reserved area.

Conclusion

The novel occluder device demonstrated excellent closure performance, biocompatibility, and puncturability in the experiment. This indicates the feasibility of conducting further catheter-based interventions on the interatrial septum.

Excess Bed Days and Hospitalization Costs Associated With 30-Day Complications Following Catheter Ablation of Atrial Fibrillation

BACKGROUND

The incidence and type of complications following catheter ablation of atrial fibrillation have been extensively examined, but the impact associated with these complications on the length of stay and hospitalization costs is unknown.

METHODS AND RESULTS

This cohort study included 20 117 adult patients (mean age 62.6±11.4 years, 30.3% women, median length of stay 1 day [interquartile range 1-2 days]) undergoing atrial fibrillation ablation in financial years 2011 to 2017 in Australia with available cost data from the National Hospital Cost Data Collection, which determines government reimbursement of health services provided. The primary outcome was the costs associated with complications occurring up to 30 days postdischarge adjusted for inflation to 2021 Australian dollars. We used generalized linear models to estimate the increase in length of stay and cost associated with complications, adjusting for patient characteristics. Within 30 days of hospital discharge, 1151 (5.72%) patients experienced a complication with bleeding (3.35%) and pericardial effusion (0.75%) being the most common. On average, the occurrence of a complication was associated with an adjusted 3.3 (95% CI, 3.1-3.6) excess bed days of hospital care (totaling 3851 days), and a $7812 (95% CI, $6754-$8870) increase in hospitalization cost (totaling $9.0 million). Most of the total excess cost was attributable to bleeding ($3.8 million, 41.9% of total excess cost) and pericardial effusion ($1.6 million, 18.2%).

CONCLUSIONS

Complications following atrial fibrillation ablation were associated with significant increase in length of stay and hospitalization costs, most of which were attributable to bleeding and pericardial effusion. Strategies to improve procedural safety and reduce health care costs should focus on these complications.

Delayed-enhancement cardiac magnetic resonance imaging detects disease progression in patients with mitral valve disease and atrial fibrillation

Objectives

The mechanism by which mitral valve (MV) disease leads to atrial fibrillation (AF) remains poorly understood. Delayed-enhancement cardiac magnetic resonance imaging (DE-MRI) has been used to assess left atrial (LA) fibrosis in patients with lone AF before catheter ablation; however, few studies have used DE-MRI to assess MV-induced LA fibrosis in patients with or without AF undergoing MV surgery.

Methods

Between March 2018 and September 2022, 38 subjects were enrolled; 15 age-matched controls, 14 patients with lone mitral regurgitation (MR), and 9 patients with MR and AF (MR + AF). Indexed LA volume, total LA wall, and regional LA posterior wall (LAPW) enhancement were defined by the DE-MRI. One-way analysis of variance was performed.

Results

LA volume and LA enhancement were associated (r = 0.451, P = .004). LA volume differed significantly between controls (37.1 ± 10.6 mL) and patients with lone MR (71.0 ± 35.9, P = .020 and controls and patients with MR + AF (99.3 ± 47.4, P < .001). The difference in LA enhancement was significant between MR + AF (16.7 ± 9.6%) versus controls (8.3 ± 3.9%, P = .006) and MR + AF versus lone MR (8.0 ± 4.8%, P = .004). Similarly, the was significantly more LAPW enhancement in the MR + AF (17.5 ± 8.7%) versus control (9.2 ± 5.1%, P = .011) and MR + AF versus lone MR (9.8 ± 6.0%, P = .020).

Conclusions

Patients with MR + AF had significantly more total and LAPW fibrosis compared with both controls and lone MR. Volume and delayed enhancement were associated, but there was no difference between MR and MR + AF.

Safety and efficacy of catheter ablation of atrial fibrillation in the very elderly (≥80 years old): Insights from the UC San Diego AF Ablation Registry

BACKGROUND

Catheter ablation improves outcomes in symptomatic atrial fibrillation (AF) patients. However, its safety and efficacy in the very elderly (≥80 years old) is not well described.

HYPOTHESIS

Ablation of AF in the very elderly is safe and effective.

METHODS

We performed a retrospective study of all patients who underwent catheter ablation enrolled in the University of California, San Diego AF Ablation Registry. The primary outcome was freedom from atrial arrhythmias on or off antiarrhythmic drugs (AADs).

RESULTS

Of 847 patients, 42 (5.0%) were 80 years of age or greater with a median age of 81.5 (80-82.3) and 805 (95.0%) were less than 80 years of age with a median age of 64.4 (57.6-70.2). Among those who were ≥80 years old, 29 were undergoing de novo ablation (69.0%), whereas in the younger cohort, 518 (64.5%) were undergoing de novo ablation (p = .548). There were no statistically significant differences in fluoroscopy (p = .406) or total procedure times (p = .076), AAD use (p = .611), or procedural complications (p = .500) between groups. After multivariable adjustment, there were no statistically significant differences in recurrence of any atrial arrhythmias on or off AAD (adjusted hazard ratio [AHR]: 0.75; 95% confidence interval [CI]: 0.45-1.23; p = .252), all-cause hospitalizations (AHR: 0.86; 95% CI: 0.46-1.60; p = .626), or all-cause mortality (AHR: 4.48; 95% CI: 0.59-34.07; p = .147) between the very elderly and the younger cohort.

CONCLUSION

In this registry analysis, catheter ablation of AF appears similarly effective and safe in patients 80 years or older when compared to a younger cohort.

Impact of Vein of Marshall Ethanol Infusion Combined with Anatomical Ablation for the Treatment of Persistent Atrial Fibrillation: A Long-Term Follow-Up Based on Implantable Loop Recorders

BACKGROUND

The best ablation treatment for persistent atrial fibrillation (PeAF) patients is still debated. The vein of Marshall (VOM) seems to be a promising target for ablation and could be combined with a linear set of ablation lesions. The aim of our study is to evaluate the incidence of AF recurrences in a PeAF population treated with a comprehensive ablation approach consisting of VOM ethanol infusion (EI), pulmonary vein isolation (PVI), a left atrial (LA) roofline, a mitral line (guided by the newly formed lesion after alcohol infusion into the VOM and validated by pacing), and a cavotricuspid isthmus line.

METHODS

Consecutive patients undergoing the first ablation procedure of catheter ablation (CA) for PeAF were enrolled. All patients underwent VOM-EI, PVI, and ablation lines along the roof of the LA, mitral, and cavotricuspid isthmus. LA voltage mapping before and after VOM-EI was also performed. An implantable loop recorder (ILR) was implanted at the end of the ablation in each patient.

RESULTS

Thirty-one consecutive patients (66 ± 8 years and 71% male) affected by PeAF were included in this study. The VOM-EI procedural phase lasted 21.4 ± 10.1 min. PV isolation and lines were validated in all subjects. The ML block was achieved within 10.8 ± 8.7 min. At a mean follow-up of 12 ± 7 months, 27 out of 31 (87%) patients remained free from AT/AF recurrences. Among the patients with recurrences, two (50%) had incomplete ablation lesions and three (75%) had "suboptimal" VOM-EI. In 23/31 patients (74%), antiarrhythmic drugs (AADs) were discontinued after 1 month of follow-up. No significant complications were reported during the follow-up.

CONCLUSIONS

this single-center experience demonstrates that VOM-EI systematically combined with an anatomical ablation set in patients with PeAF resulted in feasible, safe, and effective freedom from AF/AT recurrences in 87% of the population after a 1-year follow-up period according to an ILR.

Validation of the SCALE-CryoAF risk model to predict very late return of atrial fibrillation after cryoballoon ablation

BACKGROUND

To date, few risk models have been validated to predict recurrent atrial fibrillation (AF) >1 year after ablation. The SCALE-CryoAF score was previously derived to predict very late return of AF (VLRAF) >1 year following cryoballoon ablation (CBA), with strong predictive ability. In this study, we aim to validate the SCALE-CryoAF score for VLRAF after CBA in a novel patient cohort.

METHODS

Retrospective analysis of a prospectively maintained single-center database was performed. Inclusion criteria were pulmonary vein isolation using CBA 2017-2020. Exclusion criteria included prior ablation, <1-year follow-up, lack of pre-CBA echocardiogram, additional ablation lesion sets, and documented AF recurrence 90-365 days post-CBA. The area under the curve (AUC) of SCALE-CryoAF was compared to the derivation value and other established risk models.

RESULTS

Among 469 CBA performed, 241 (61% male, 62.8 ±11.7 years old) cases were included in analysis. There were 37 (15.4%) patients who developed VLRAF. Patients with VLRAF had a higher SCALE-CryoAF score (VLRAF 5.4 ± 2.7; no VLRAF 3.1 ± 2.9; p<0.001). SCALE-CryoAF was linearly associated with VLRAF (y=14.35x-11.72, R2=0.99), and a score > 5 had a 32.7% risk of VLRAF. The SCALE-CryoAF risk model predicted VLRAF with an AUC of 0.74, which was similar to the derivation value (AUCderivation: 0.73) and statistically superior to MB-LATER, CHA2DS2-VASc, and CHADS2 scores.

CONCLUSIONS

The current analysis validates the ability of SCALE-CryoAF to predict VLRAF after CBA in a novel patient cohort. Patients with a high SCALE-CryoAF score should be monitored closely for recurrent AF >1 year following CBA.

Esophageal luminal temperature monitoring using a multi-sensor probe lowers the risk of esophageal injury in cryo and radiofrequency catheter ablation for atrial fibrillation

BACKGROUND

Esophageal luminal temperature monitoring is a commonly used strategy to reduce esophageal thermal injury in catheter ablation for atrial fibrillation (AFib).

OBJECTIVES

We sought to compare the incidence of endoscopically detected esophageal lesions (EDEL) between two commonly used esophageal luminal temperature probes.

METHODS

Consecutive patients undergoing ablation with esophageal luminal temperature monitoring and upper endoscopy within 24 h after ablation were included.

RESULTS

Four hundred forty-five patients (64 ± 10 years, 44% female) were included. Esophageal temperature monitoring was done with a single-sensor probe in 213 (48%) and multi-sensor probe in 232 (52%). Cryoballoon (CB) ablation was performed in 118 (27%) and radiofrequency (RF) ablation in 327 (73%) of patients. EDEL was present in 94 (22.9%) of which 85 were mild, 8 were moderate, and 1 was severe, and none progressed to atrial-esophageal fistula. The use of the multi-sensor probe during CB ablation was associated with a reduction in EDEL compared to single sensor (6.8% vs 24.3%; P = 0.016). Similarly, in the RF ablation group, EDEL was present in 19.5% of the multi-sensor group vs 32.8% in the single-sensor group (P = 0.001). Logistic regression showed that multi-sensor probe use was associated with reduction in EDEL with an odds ratio of 0.23 in CB ablation (P = 0.024) and 0.44 for RF ablation (P = 0.001).

CONCLUSIONS

Esophageal luminal temperature monitoring during AFib ablation using a multi-sensor probe was associated with a significant reduction in EDEL compared to a single-sensor probe.

Colchicine for the Prevention of Recurrent Arrhythmia After Catheter Ablation of Atrial Fibrillation: Results of a Single-Center, Retrospective Study

BACKGROUND

There is evidence to suggest that colchicine reduces the risk of recurrent atrial fibrillation (AF) after catheter ablation; however, the tolerability and safety of colchicine in routine practice is unknown.

METHODS

Patients undergoing catheter ablation for AF who received colchicine after ablation were matched 1:1 to patients who did not by age, sex, and renal function. Recurrent AF was compared between groups categorically at 12 months and via propensity weighted Cox proportional hazards models with and without a 3-month blanking period.

RESULTS

Overall, 180 patients (n = 90 colchicine and n = 90 matched controls) were followed for a median (Q1, Q3) of 10.3 (7.0, 12.0) months. Mean age was 65.3 ± 9.1 years, 33.9% were women, mean CHA2DS2-VASc score was 2.9 ± 1.5, and 51.1% had persistent AF. Most patients (70%) received colchicine 0.6 mg daily for a median of 30 days. In the colchicine group, 55 patients (61.1%) were receiving at least one known interacting medication with colchicine. After ablation, one patient required colchicine dose reduction and four patients required discontinuation. After adjusting for covariate imbalance using propensity weighting, no significant association between colchicine use and AF recurrence was identified (adjusted hazard ratio 0.94, 95% confidence interval [CI] 0.48-1.85; p = 0.853). No significant association was found between colchicine use and all-cause hospitalizations (adjusted odds ratio 0.74, 95% CI 0.28-1.96; p = 0.548).

CONCLUSION

Despite the frequent presence of drug-drug interactions, a 30-day course of colchicine is well-tolerated after AF ablation; however, we did not observe any association between colchicine and lower rates of AF recurrence or hospitalization.

Chronic Effect of HotBalloon-Based Wide Planar Ablation on Epicardial Adipose Tissue in Persistent Atrial Fibrillation

Background: Adverse atrial remodeling, including epicardial adipose tissue (EAT) deposition in the left atrium (LA), is implicated in atrial fibrillation (AF). Radiofrequency hotballoon (RHB) ablation can produce wide planar lesions because the balloon is highly compliant; however, chronic effects of RHB ablation on structural remodeling remain unknown. This clinical-experimental investigation characterized chronic effects of RHB ablation on EAT in persistent AF (PsAF). Methods and Results: The clinical study involved 91 patients (obese, n=30; non-obese, n=61) undergoing RHB ablation for PsAF. LA-EAT was assessed from computed tomography images obtained before ablation and 6 months later. Tissue effects of RHB ablation were explored in a chronic swine model. RHB ablation significantly reduced LA volume (mean [±SD] 177.7±29.7 vs. 138.4±29.6 mL; P<0.001) and LA-EAT volume (median [interquartile range] 22.0 [12.4-33.3] vs. 16.5 [7.9-25.8] mL; P<0.001). The reduction in EAT was significantly greater in the pulmonary vein (PV) antrum than in other LA regions (37.9% vs. 15.8%; P<0.001). The percentage reduction in PV antrum EAT was equivalent between obese and non-obese patients, as was the postablation success rate (73% vs. 70%; P=0.77). RHB ablation produced transmural lesions reaching the pigs' epicardial fat region. Conclusions: RHB-based planar-transmural lesions altered the structurally remodeled LA, including EAT. Further studies are needed to determine whether factors other than PV isolation contribute to the clinical success of RHB ablation.

Initial multicenter clinical experience with the first-generation endoscopic guided laser balloon in Japan

BACKGROUND

Isolation of the pulmonary veins (PVs) is the golden standard for atrial fibrillation (AF) ablation. To achieve a permanent PV isolation, the endoscopic guided HeartLight laser balloon system was invented. We analyzed the safety and efficacy of this laser balloon system.

METHODS AND RESULTS

Three hundred four patients from 21 investigational sites inside Japan were enrolled in this study. One thousand sixty-two out of 1175 PVs (90.4%) were isolated using the HeartLight laser balloon. The isolation rate of the left superior, left inferior, right superior, and right inferior PVs was 87.8%, 91.3%, 91.6%, and 92.1%, respectively. The procedure time, defined as the time from the venous access to taking out the balloon, was 155 ± 39 min. The fluoroscopic time was 44 ± 25 min. The mean follow-up period was 309 ± 125 days. The freedom from AF recurrence at 3 months was 89.0% and at 12 months 82.1%. Adverse events occurred in 22 patients (7.2%) including phrenic nerve injury lasting more than 3 months in 1.6% and strokes in 1.0% of the patients.

CONCLUSIONS

This initial experience demonstrated that the laser balloon ablation was feasible for PV isolation in Japanese AF patients.

Histological validation of atrial structural remodelling in patients with atrial fibrillation

BACKGROUND AND AIMS

This study aimed to histologically validate atrial structural remodelling associated with atrial fibrillation.

METHODS AND RESULTS

Patients undergoing atrial fibrillation ablation and endomyocardial atrial biopsy were included (n = 230; 67 ± 12 years old; 69 women). Electroanatomic mapping was performed during right atrial pacing. Voltage at the biopsy site (Vbiopsy), global left atrial voltage (VGLA), and the proportion of points with fractionated electrograms defined as ≥5 deflections in each electrogram (%Fractionated EGM) were evaluated. SCZtotal was calculated as the total width of slow conduction zones, defined as regions with a conduction velocity of <30 cm/s. Histological factors potentially associated with electroanatomic characteristics were evaluated using multiple linear regression analyses. Ultrastructural features and immune cell infiltration were evaluated by electron microscopy and immunohistochemical staining in 33 and 60 patients, respectively. Fibrosis, intercellular space, myofibrillar loss, and myocardial nuclear density were significantly associated with Vbiopsy (P = .014, P < .001, P < .001, and P = .002, respectively) and VGLA (P = .010, P < .001, P = .001, and P < .001, respectively). The intercellular space was associated with the %Fractionated EGM (P = .001). Fibrosis, intercellular space, and myofibrillar loss were associated with SCZtotal (P = .028, P < .001, and P = .015, respectively). Electron microscopy confirmed plasma components and immature collagen fibrils in the increased intercellular space and myofilament lysis in cardiomyocytes, depending on myofibrillar loss. Among the histological factors, the severity of myofibrillar loss was associated with an increase in macrophage infiltration.

CONCLUSION

Histological correlates of atrial structural remodelling were fibrosis, increased intercellular space, myofibrillar loss, and decreased nuclear density. Each histological component was defined using electron microscopy and immunohistochemistry studies.

Freedom from atrial arrhythmia and other clinical outcomes at 5 years and beyond after catheter ablation of atrial fibrillation: a systematic review and meta-analysis

AIMS

Catheter ablation of atrial fibrillation (AF) is now a mainstream procedure although long-term outcomes are uncertain. We performed a systematic review and meta-analysis of procedural outcomes at 5 years and beyond.

METHODS AND RESULTS

We searched PubMed and Embase and after the screening, identified 73 studies (67 159 patients) reporting freedom from atrial arrhythmia, all-cause death, stroke, and major bleeding at ≥5 years after AF ablation. The pooled mean age was 59.7y, 71.5% male, 62.2% paroxysmal AF, and radiofrequency was used in 78.1% of studies. Pooled incidence of freedom from atrial arrhythmia at 5 years was 50.6% (95%CI 45.5-55.7%) after a single ablation and 69.7% [95%CI (confidence interval) 63.8-75.3%) after multiple procedures. The incidence was higher among patients with paroxysmal compared with non-paroxysmal AF after single (59.7% vs. 33.3%, p = 0.002) and multiple (80.8% vs. 60.6%, p < 0.001) ablations but was comparable between radiofrequency and cryoablation. Pooled incidences of other outcomes were 6.0% (95%CI 3.2-9.7%) for death, 2.4% (95%CI 1.4-3.7%) for stroke, and 1.2% (95%CI 0.8-2.0%) for major bleeding at 5 years. Beyond 5 years, freedom from arrhythmia recurrence remained largely stable (52.3% and 64.7% after single and multiple procedures at 10 years), while the risk of stroke and bleeding increased over time.

CONCLUSION

Nearly 70% of patients having multiple ablations remained free from atrial arrhythmia at 5 years, with the incidence slightly decreasing beyond this period. Risk of death, stroke, and major bleeding at 5 years were low but increased over time, emphasizing the importance of long-term thromboembolism prevention and bleeding risk management.

Association of isoproterenol infusion during catheter ablation of atrial fibrillation with outcomes: insights from the UC San Diego AF Ablation Registry

BACKGROUND

High-dose isoproterenol infusion is a useful provocative maneuver to elicit triggers of atrial fibrillation (AF) during ablation. We evaluated whether the use of isoproterenol infusion to elicit triggers of AF after ablation is associated with differential outcomes.

METHODS

We performed a retrospective study of all patients who underwent de novo radiofrequency catheter ablation of AF enrolled in the University of California, San Diego AF Ablation Registry. The primary outcome was freedom from atrial arrhythmias on or off antiarrhythmic drugs (AAD).

RESULTS

Of 314 patients undergoing AF ablation, 235 (74.8%) received isoproterenol while 79 (25.2%) did not. Among those who received isoproterenol, 11 (4.7%) had additional triggers identified. There were no statistically significant differences in procedure time (p = 0.432), antiarrhythmic drug use (p = 0.289), procedural complications (p = 0.279), recurrences of atrial arrhythmias on or off AAD [adjusted hazard ratio (AHR) 0.92 (95% CI 0.58-1.46); p = 0.714], all-cause hospitalizations [AHR 1.00 (95% CI 0.60-1.67); p = 0.986], or all-cause mortality [AHR 0.14 (95% CI 0.01-3.52); p = 0.229] between groups.

CONCLUSIONS

In this registry analysis, use of isoproterenol is safe but was not associated with a reduction in recurrence of atrial arrhythmias.

A computational modeling framework for pre-clinical evaluation of cardiac mapping systems

There are a variety of difficulties in evaluating clinical cardiac mapping systems, most notably the inability to record the transmembrane potential throughout the entire heart during patient procedures which prevents the comparison to a relevant "gold standard". Cardiac mapping systems are comprised of hardware and software elements including sophisticated mathematical algorithms, both of which continue to undergo rapid innovation. The purpose of this study is to develop a computational modeling framework to evaluate the performance of cardiac mapping systems. The framework enables rigorous evaluation of a mapping system's ability to localize and characterize (i.e., focal or reentrant) arrhythmogenic sources in the heart. The main component of our tool is a library of computer simulations of various dynamic patterns throughout the entire heart in which the type and location of the arrhythmogenic sources are known. Our framework allows for performance evaluation for various electrode configurations, heart geometries, arrhythmias, and electrogram noise levels and involves blind comparison of mapping systems against a "silver standard" comprised of computer simulations in which the precise transmembrane potential patterns throughout the heart are known. A feasibility study was performed using simulations of patterns in the human left atria and three hypothetical virtual catheter electrode arrays. Activation times (AcT) and patterns (AcP) were computed for three virtual electrode arrays: two basket arrays with good and poor contact and one high-resolution grid with uniform spacing. The average root mean squared difference of AcTs of electrograms and those of the nearest endocardial action potential was less than 1 ms and therefore appears to be a poor performance metric. In an effort to standardize performance evaluation of mapping systems a novel performance metric is introduced based on the number of AcPs identified correctly and those considered spurious as well as misclassifications of arrhythmia type; spatial and temporal localization accuracy of correctly identified patterns was also quantified. This approach provides a rigorous quantitative analysis of cardiac mapping system performance. Proof of concept of this computational evaluation framework suggests that it could help safeguard that mapping systems perform as expected as well as provide estimates of system accuracy.

Advances in basic and translational research in atrial fibrillation

Atrial fibrillation (AF) is a very common cardiac arrhythmia with an estimated prevalence of 33.5 million patients globally. It is associated with an increased risk of death, stroke and peripheral embolism. Although genetic studies have identified a growing number of genes associated with AF, the definitive impact of these genetic findings is yet to be established. Several mechanisms, including electrical, structural and neural remodelling of atrial tissue, have been proposed to contribute to the development of AF. Despite over a century of exploration, the molecular and cellular mechanisms underlying AF have not been fully established. Current antiarrhythmic drugs are associated with a significant rate of adverse events and management of AF using ablation is not optimal, especially in cases of persistent AF. This review discusses recent advances in our understanding and management of AF, including new concepts of epidemiology, genetics and pathophysiological mechanisms. We review the current status of antiarrhythmic drug therapy for AF, new potential agents, as well as mechanism-based AF ablation. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.

Multicenter Study of Surgical Ablation for Atrial Fibrillation in Aortic Valve Replacement

There is controversy regarding appropriate surgical ablation procedures concomitant with nonmitral valve surgery. We retrospectively investigated the impact of surgical ablation for atrial fibrillation during aortic valve replacement between 2010 and 2015 in 16 institutions registered through the Japanese Society for Arrhythmia Surgery. Clinical data of 171 patients with paroxysmal and nonparoxysmal atrial fibrillation undergoing aortic valve replacement were collected and classified into full maze operation (n = 79), pulmonary vein isolation (PVI) (n = 56), and no surgical ablation (n = 36) groups. All patients were followed up and electrocardiograms were recorded in 68% at 2 years. The myocardial ischemia time was significantly longer in the maze group than the others during isolated aortic valve replacement (p ≤ 0.01), but there were no significant differences in 30-day or 2-year mortality rates between groups. The ratios of sinus rhythm at 2 years in paroxysmal and nonparoxysmal atrial fibrillation in the maze group versus PVI group were 87% versus 97%, respectively (p = 0.24) and 53% versus 42%, respectively (p = 0.47). No patients with nonparoxysmal atrial fibrillation in the no surgical ablation group maintained sinus rhythm at 2 years. In conclusion, both maze and PVI during aortic valve replacement are valuable strategies to restore sinus rhythm at 2 years and result in favorable early and midterm survival rates.

Positional obstructive sleep apnea in patients with atrial fibrillation

PURPOSE

Obstructive sleep apnea (OSA) is a common, potentially modifiable condition implicated in the pathogenesis of atrial fibrillation (AF). The presence and severity of OSA is largely sleep position-dependent, yet there is high variability in positional dependence among patients with OSA. We investigated the prevalence of positional OSA (POSA) and examined associated factors in patients with AF.

METHODS

We recruited an equal number of patients with and without AF who underwent diagnostic polysomnography. Patients included had ≥ 120 min of total sleep time with 30 min of sleep in both supine and lateral positions. POSA was defined as an overall apnea hypopnea index (AHI) ≥ 5/h, supine AHI (sAHI) ≥ 5/h, and sAHI greater than twice the non-supine AHI. POSA prevalence was compared in patients with and without AF adjusting for age, sex, OSA severity, and heart failure.

RESULTS

A total of patients (male: 56%, mean age 62 years) were included. POSA prevalence was similar between the two groups (46% vs. 39%; p = 0.33). Obesity and severe OSA (AHI ≥ 30/h) were associated with low likelihood of POSA (OR [CI] of 0.17 [0.09-0.32] and 0.28 [0.12-0.62]). In patients with AF, male sex was associated with a higher likelihood of POSA (OR [CI] of 3.16 [1.06-10.4]).

CONCLUSION

POSA is common, affecting more than half of patients with AF, but the prevalence was similar in those without AF. Obesity and more severe OSA are associated with lower odds of POSA. Positional therapy should be considered in patients with mild OSA and POSA.

Economic and Health Value of Delaying Atrial Fibrillation Progression Using Radiofrequency Catheter Ablation

BACKGROUND

Radiofrequency catheter ablation (RFCA) is an established treatment for atrial fibrillation (AF) refractory to antiarrhythmic drugs. The economic value of RFCA in delaying disease progression has not been quantified.

METHODS

An individual-level, state-transition health economic model estimated the impact of delayed AF progression using RFCA versus antiarrhythmic drug treatment for a hypothetical sample of patients with paroxysmal AF. The model incorporated the lifetime risk of progression from paroxysmal AF to persistent AF, informed by data from the ATTEST (Atrial Fibrillation Progression Trial). The incremental effect of RFCA on disease progression was modeled over a 5-year duration. Annual crossover rates were also included for patients in the antiarrhythmic drug group to mirror clinical practice. Estimates of discounted costs and quality-adjusted life years asssociated with health care utilization, clinical outcomes, and complications were projected over patients' lifetimes.

RESULTS

From the payer's perspective, RFCA was superior to antiarrhythmic drug treatment with an estimated mean net monetary benefit per patient of $8516 ($148-$16 681), driven by reduced health care utilization, cost, and improved quality-adjusted life years. RFCA reduced mean (95% CI) per-patient costs by $73 (-$2700 to $2200), increased mean quality-adjusted life years by 0.084 (0.0-0.17) and decreased the mean number of cardiovascular-related health care encounters by 24%.

CONCLUSIONS

RFCA is a dominant (less costly and more effective) treatment strategy for patients with AF, especially those with early AF for whom RFCA could delay progression to advanced AF. Increased utilization of RFCA-particularly among patients earlier in their disease progression-may provide clinical and economic benefits.

Detailed analysis of the lesion formation using a diamond tip catheter in an ex vivo experimental model

BACKGROUND

A novel Diamond Temp™ (DT; Medtronic, Minneapolis, MN, USA) catheter has enabled performing a surface temperature-controlled ablation. The chemical vapor deposition diamond of the ablation catheter acts as a thermal radiator and is useful for effective cooling of the ablation catheter tip. However, a detailed analysis of the lesion formation with this catheter remains unknown.

METHODS

DT catheters were used in an excised swine heart experimental model. A cross-sectional analysis of 60-s lesions [a combination of various energy power settings (30, 40, and 50 W), and various contact forces (CF) (10, 30, and 50 g)] and a longitudinal analysis [a combination of various powers (40 W or 50 W), various CFs (10, 30, and 50 g), and various ablation times (5 s, 10 s, 15 s, 20 s, 25 s, 30 s, and 60 s)] of the DT catheter were analyzed.

RESULTS

The maximum lesion depth, maximum diameter, and lesion volume with a 10 g ablation were significantly lower than those with a 30 g or 50 g ablation. There were no significant differences in the lesion formation between the 30 g ablation and 50 g ablation under each radiofrequency (RF) power setting. The impedance drops with steam pops were significantly greater than those without steam pops (pop (+) vs. pop (-), 26.2 ± 6.6 Ohm vs. 18.4 ± 7.1 Ohm, p = 0.0001). A non-linear, time-dependent increase in the lesion depth and diameter was observed for all power and CF settings. Comparing the lesion depth and diameter between 40 W and 50 W under the same CF setting and same ablation time, most of the settings had no significant difference.

CONCLUSION

Ablation lesions created with the DT catheter were similar to other catheters. Similar ablation lesions were created with the 40 W or 50 W ablation under the same CF setting and same ablation time. Regardless of the ablation power, monitoring the general impedance during the RF application was indispensable for a safe procedure.

Oral Class I and III antiarrhythmic drugs for maintaining sinus rhythm after catheter ablation of atrial fibrillation

BACKGROUND

Recurrence of atrial tachyarrhythmias (ATa) following catheter ablation for atrial fibrillation (AF) is a common problem. Antiarrhythmic drugs have been used shortly after ablation in an attempt to maintain sinus rhythm, particularly Class I and III agents. However, it still needs to be established if the use of Class I or III antiarrhythmic medications, or both, reduce the risk of recurrence of ATa.

OBJECTIVES

To assess the effects of oral Class I and III antiarrhythmic drugs versus control (standard medical therapy without Class I or III antiarrhythmics, or placebo) for maintaining sinus rhythm in people undergoing catheter ablation for AF.

SEARCH METHODS

We systematically searched CENTRAL, MEDLINE, Embase, Web of Science Core Collection, and two clinical trial registers without restrictions on language or date to 5 August 2022.

SELECTION CRITERIA

We sought published, unpublished, and ongoing parallel-design, randomised controlled trials (RCTs) involving adult participants undergoing ablation for AF, with subsequent comparison of Class I and/or III antiarrhythmic use versus control (standard medical therapy or non-Class I and/or III antiarrhythmic use).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane and performed meta-analyses with risk ratios (RR) and Peto odds ratios (Peto OR). Our primary outcomes were recurrence of atrial tachyarrhythmias; adverse events: thromboembolic events; adverse events: myocardial infarction; adverse events: new diagnosis of heart failure; and adverse events: requirement for one or more hospitalisations for atrial tachyarrhythmia. Our secondary outcomes were: all-cause mortality; and requirement for one or more repeat ablations. Where possible, we performed comparison analysis by Class I and/or III antiarrhythmic and divided follow-up periods for our primary outcome. We performed comprehensive assessments of risk of bias and certainty of evidence applying the GRADE methodology.

MAIN RESULTS

We included nine RCTs involving a total of 3269 participants. Participants were on average 59.3 years old; 71.0% were male; and 72.9% and 27.4% had paroxysmal and persistent AF, respectively. Class I and/or III antiarrhythmics may reduce recurrence of ATa at 0 to 3 months postablation (risk ratio (RR) 0.74, 95% confidence interval (CI) 0.59 to 0.94, 8 trials, 3046 participants, low-certainty evidence) and likely reduce recurrence at > 3 to 6 months, our a priori primary time point (RR 0.85, 95% CI 0.78 to 0.93, 5 trials, 2591 participants, moderate-certainty evidence). Beyond six months the evidence is very uncertain, and the benefit of antiarrhythmics may not persist (RR 1.14, 95% CI 0.84 to 1.55, 4 trials, 2244 participants, very low-certainty evidence). The evidence suggests that Class I and/or III antiarrhythmics may not increase the risk of thromboembolic events, myocardial infarction, all-cause mortality, or requirement for repeat ablation, at 0 to 3, > 3 to 6, and > 6 months (where data were available; low- to very low-certainty evidence). The use of Class I and/or III antiarrhythmics postablation likely reduces hospitalisations for ATa by approximately 57% at 0 to 3 months (RR 0.43, 95% CI 0.28 to 0.64, moderate-certainty evidence). No data were available beyond three months. No data were available on new diagnoses of heart failure. Fewer data were available for Class I and III antiarrhythmics individually. Based on only one and two trials (n = 125 to 309), Class I antiarrhythmics may have little effect on recurrence of ATa at 0 to 3, > 3 to 6, and > 6 months (RR 0.88, 95% CI 0.64 to 1.20, 2 trials, 309 participants; RR 0.54, 95% CI 0.25 to 1.19, 1 trial, 125 participants; RR 0.87, 95% CI 0.57 to 1.32, 1 trial, 125 participants; low-certainty evidence throughout); requirement for hospitalisation for ATa at 0 to 3 months (low-certainty evidence); or requirement for repeat ablation at 0 to 3 months (low-certainty evidence). No data were available for thromboembolic events, myocardial infarction, new diagnosis of heart failure, or all-cause mortality at any time points, or hospitalisation or repeat ablation beyond three months. Class III antiarrhythmics may have little effect on recurrence of ATa at up to 3 months and at > 3 to 6 months (RR 0.76, 95% CI 0.50 to 1.16, 4 trials, 599 participants, low-certainty evidence; RR 0.82, 95% CI 0.62 to 1.09, 2 trials, 318 participants, low-certainty evidence), and beyond 6 months one trial reported a possible increase in recurrence of ATa (RR 1.95, 95% CI 1.29 to 2.94, 1 trial, 112 participants, low-certainty evidence). Class III antiarrhythmics likely reduce hospitalisations for ATa at 0 to 3 months (RR 0.40, 95% CI 0.26 to 0.63, moderate-certainty evidence), and may have little effect on all-cause mortality (low- to very low-certainty evidence). The effect of Class III antiarrhythmics on thromboembolic events and requirement for repeat ablation was uncertain (very low-certainty evidence for both outcomes). No data were available for myocardial infarction or new diagnosis of heart failure at any time point, outcomes other than recurrence beyond 6 months, or for hospitalisation and repeat ablation > 3 to 6 months. We assessed the majority of included trials as at low or unclear risk of bias. One trial reported an error in the randomisation process, raising the potential risk of selection bias; most of the included trials were non-blinded; and two trials were at high risk of attrition bias.

AUTHORS' CONCLUSIONS

We found evidence to suggest that the use of Class I and/or III antiarrhythmics up to 3 months after ablation is associated with a reduced recurrence of ATa 0 to 6 months after ablation, which may not persist beyond 6 months, and an immediate reduction in hospitalisation for ATa 0 to 3 months after ablation. The evidence suggests there is no difference in rates of all-cause mortality, thromboembolic events, or myocardial infarction between Class I and/or III antiarrhythmics versus control.

Failure of Guidelines and Consensus Statements to Recommend Follow-up for Chronic Cardiovascular Conditions

BACKGROUND

Many cardiac conditions require long-term clinical follow-up to monitor progression of disease and tolerance and adherence to therapies. Providers are often unsure as to the frequency of clinical follow-up and who should provide the follow-up. In the absence of formal guidance, patients may be seen more frequently than necessary - thereby limiting clinic space for other patients, or not frequently enough, potentially leading to undetected progression of disease.

OBJECTIVES

To determine the extent to which guidelines (GL)/consensus statements (CS) provide guidance about appropriate follow-up for common cardiovascular conditions.

METHODS

We identified 31 chronic cardiovascular disease conditions for which long-term (beyond 1 year) follow-up is indicated and used PubMed and professional society websites to identify all relevant GL/CS (n = 33) regarding these chronic cardiac conditions.

RESULTS

Of the 31 cardiac conditions reviewed, GL/CS contained no recommendation or vague recommendation for long-term follow-up for 7 of the conditions. Of the 24 conditions with recommendations for follow-up, 3 had recommendations for imaging follow-up only without mention of clinical follow-up. Of the 33 GL/CS reviewed, 17 made any recommendations about long-term follow-up. When recommendations were made regarding follow-up, they were often vague, using terminology such as "as needed".

CONCLUSIONS

Half of GL/CS fail to provide recommendations for clinical follow-up of common cardiovascular conditions. Writing groups for GL/CS should adopt a standard of routinely including recommendations for follow-up including specific advice about level of expertise needed (eg, primary care physician, cardiologist), need for imaging or testing, and frequency of follow-up.

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.

Real-World Investigation on Anticoagulation Management Before and After Catheter Ablation for Atrial Fibrillation in Japan - Periprocedural and Long-Term Outcomes

BACKGROUND

Optimal periprocedural oral anticoagulant (OAC) therapy before catheter ablation (CA) for atrial fibrillation (AF) and the safety profile of OAC discontinuation during the remote period (from 31 days and up to 1 year after CA) have not been well defined.

METHODS AND RESULTS

The RYOUMA registry is a prospective multicenter observational study of Japanese patients who underwent CA for AF in 2017-2018. Of the 3,072 patients, 82.3% received minimally interrupted direct-acting OACs (DOACs) and 10.2% received uninterrupted DOACs. Both uninterrupted and minimally interrupted DOACs were associated with an extremely low thromboembolic event rate. Female, long-standing persistent AF, low creatinine clearance, hepatic disorder, and high intraprocedural heparin dose were independent factors associated with periprocedural major bleeding. At 1 year after CA, DOAC was continued in 55.9% of patients and warfarin in 56.4%. The incidence of thromboembolic and major bleeding events for 1 year was 0.3% and 1.2%, respectively. Age ≥73 years, dementia, and AF recurrence were independently associated with major bleeding events. Univariate analyses revealed that warfarin continuation and off-label overdose of DOACs were risk factors for major bleeding after CA.

CONCLUSIONS

High intraprocedural dose of heparin was associated with periprocedural major bleeding events. At 1 year after CA, over half of the patients had continued OAC therapy. Thromboembolic events were extremely low; however, major bleeding occurred in 1.2%. Age ≥73 years, dementia, and AF recurrence were independently associated with major bleeding after CA.

Time dependency in the radiofrequency lesion formation for a local impedance guided catheter in an ex vivo experimental model

Background

The local impedance (LI) is an emerging technology that monitors tissue-catheter coupling during radiofrequency (RF) ablation. The relationships between the LI, RF delivery time, and lesion formation remain unclear.

Methods

Using an LI-enabled RF catheter in an ex vivo experimental model, RF lesions were created combined with various steps in the power (40 and 50 W), CF (10 g, 30 g, and 50 g), and time (10s, 20s, 30s, 40s, 50s, and 60s at 40 W and 5 s, 10s, 20s, 30s, 40s, 50s, and 60s at 50 W). The correlations between the LI drop, lesion size, and RF delivery time were evaluated. The rate of change in the time-dependent gain in the LI, depth, and diameter and the time to reach 90% decay of the peak dY/dT (time to 90% decay) were assessed.

Results

The correlation between the LI drop and ablation time revealed non-linear changes. The time to a 90% decay in the LI drop differed depending on the RF ablation setting and was always shorter with the 50 W setting than 40 W setting. The LI drop always correlated with the lesion formation under all ablation power settings. Deeper or wider lesions were predominantly created within the time to 90% decay of the LI drop.

Conclusion

The LI drop was useful for predicting lesion sizes. Deeper or wider lesions cannot be obtained with a longer ablation than the 90% decay time of the LI drop. A shorter ablation than the 90% decay time of the LI drop would be preferable for an effective ablation.

Preoperative Prediction of Catheter Ablation Outcome in Persistent Atrial Fibrillation Patients through Spectral Organization Analysis of the Surface Fibrillatory Waves

Catheter ablation (CA) is a commonly used treatment for persistent atrial fibrillation (AF). Since its medium/long-term success rate remains limited, preoperative prediction of its outcome is gaining clinical interest to optimally select candidates for the procedure. Among predictors based on the surface electrocardiogram, the dominant frequency (DF) and harmonic exponential decay (γ) of the fibrillatory waves (f-waves) have reported promising but clinically insufficient results. Hence, the main goal of this work was to conduct a broader analysis of the f-wave harmonic spectral structure to improve CA outcome prediction through several entropy-based measures computed on different frequency bands. On a database of 151 persistent AF patients under radio-frequency CA and a follow-up of 9 months, the newly introduced parameters discriminated between patients who relapsed to AF and those who maintained SR at about 70%, which was statistically superior to the DF and approximately similar to γ. They also provided complementary information to γ through different combinations in multivariate models based on lineal discriminant analysis and report classification performance improvement of about 5%. These results suggest that the presence of larger harmonics and a proportionally smaller DF peak is associated with a decreased probability of AF recurrence after CA.

Preprocedural Multimodality Imaging in Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide and is associated with increased risk of heart failure, stroke, and death. In current medical practice, multimodality imaging is routinely used in the management of AF. Twenty-one years ago, the ACUTE trial (Assessment of Cardioversion Using Transesophageal Echocardiography) results were published, and the management of AF changed forever by incorporating transesophageal echocardiography guided cardioversion of patients in AF for the first time. Current applications of multimodality imaging in AF in 2022 include the use of transesophageal echocardiography and computed tomography before cardioversion to exclude left atrial thrombus and in left atrial appendage occlusion device implantation. Transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance are clinically used for AF ablation planning. The decision to use a particular imaging modality in AF is based on patient's characteristics, guideline recommendation, institutional preferences, expertise, and cost. In this first of 2-part review series, we discuss the preprocedural role of echocardiography, computed tomography, and cardiac magnetic resonance in the AF, with regard to their clinical applications, relevant outcomes data and unmet needs, and highlights future directions in this rapidly evolving field.

Hybrid Ablation of Nonparoxysmal Atrial Fibrillation: The Convergent and Totally Thoracoscopic Approaches

Nonparoxysmal atrial fibrillation continues to challenge electrophysiologist and surgeons alike. Stand-alone endocardial catheter ablation has resulted in less than satisfying results, and while the on-pump Cox-Maze surgery has excellent results, the invasiveness has limited its adoption amongst both referring providers and surgeons. The CONVERGE IDE trial has shed new light on this once dim problem. EPs and Surgeons are now working together in a Hybrid Team Ablation Approach to provide a combined ablation strategy that has improved patient outcomes and rekindled the collaboration necessary to better patient outcomes. We herein summarize the current Hybrid Team Ablation Approaches (CONVERGE and Totally Thoracoscopic) with nonparoxysmal atrial fibrillation.