Prevention of esophageal lesions during atrial fibrillation catheter ablation using esophageal temperature monitoring: A systematic review and meta-analysis.

INTRODUCTION: The use of esophageal temperature monitoring (ETM) for the prevention of esophageal injury during atrial fibrillation (AF) ablation is often advocated. However, evidence supporting its use is scarce and controversial. We therefore aimed to review the evidence assessing the efficacy of ETM for the prevention of esophageal injury. METHODS: We performed a meta-analysis and systematic review of the available literature from inception to December 31, 2022. All studies comparing the use of ETM, versus no ETM, during radiofrequency (RF) AF ablation and which reported the incidence of endoscopically detected esophageal lesions (EDELs) were included. RESULTS: Eleven studies with a total of 1112 patients undergoing RF AF ablation were identified. Of those patients, 627 were assigned to ETM (56%). The overall incidence of EDELs was 9.8%. The use of ETM during AF ablation was associated with a non significant increase in the incidence of EDELs (12.3% with ETM, vs. 6.6 % without ETM, odds ratio, 1.44, 95%CI, 0.49, 4.22, p = .51, I2 = 72%). The use of ETM was associated with a significant increase in the energy delivered specifically on the posterior wall compared to patients without ETM (mean power difference: 5.13 Watts, 95% CI, 1.52, 8.74, p = .005). CONCLUSIONS: The use of ETM does not reduce the incidence of EDELs during RF AF ablation. The higher energy delivered on the posterior wall is likely attributable to a false sense of safety that may explain the lack of benefit of ETM. Further randomized controlled trials are needed to provide conclusive results.

Ventricular Arrhythmias and Sudden Death Following Percutaneous Pulmonary Valve Implantation in Pediatric Patients.

Reports have suggested a transient increase in ventricular ectopy early after percutaneous pulmonary valve implantation (PPVI). Little is known about the potential for more serious ventricular arrhythmias (VA) in children who undergo PPVI. We sought to evaluate the incidence of severe VA following PPVI in a pediatric population and to explore potential predictive factors. A retrospective cohort study was conducted of patients who underwent PPVI under 20 years of age in our institution from January 2007 to December 2019. The primary outcome of severe VA was defined as sustained and/or hemodynamically unstable ventricular tachycardia (VT), inducible sustained VT, or sudden death of presumed arrhythmic etiology. A total of 21 patients (mean age 16.2 ± 2.1 years; 66.7% male) underwent PPVI. The majority of patients (N = 15; 71.4%) had tetralogy of Fallot (TOF) or TOF-like physiology, with the most common indication being pulmonary insufficiency (N = 10; 47.6%). During a median follow-up of 29.6 months (IQR 10.9-44.0), severe VA occurred in 3 (14.3%) patients aged 15.6 (IQR 14.7-16.1) a median of 12.3 months (IQR 11.2-22.3) after PPVI. All events occurred in patients with TOF-like physiology following Melody valve implant. In conclusion, severe VA can occur long after PPVI in a pediatric population, particularly in those with TOF-like physiology. Further studies are required to elucidate underlying mechanisms and assess strategies to mitigate risks.

[Prevention of thromboembolic complications in adult congenital heart disease]. / Prévention des complications thromboemboliques des patients adultes porteurs de cardiopathie congénitale.

Thromboembolic complications in adults with congenital heart disease are frequent and responsible for significant morbidity and mortality. Their prevention frequently requires long-term thromboprophylaxis. In this article, we discuss the specificities that must be considered when stratifying the thromboembolic risk in these patients, the different therapeutic strategies, particularly the place of direct oral anticoagulants.

Les complications thromboemboliques des adultes porteurs d'une cardiopathie congénitale sont fréquentes et responsables d'une importante morbi-mortalité. Leur prévention passe fréquemment par la mise en place d'une thromboprophylaxie au long cours. Dans cet article, nous discutons des spécificités qui doivent être prises en compte lors de la stratification du risque thromboembolique de ces patients, des différentes stratégies thérapeutiques et notamment de la place des anticoagulants oraux directs.

[An update on some atypical electrocardiographic forms of acute coronary syndrome The "STEMI equivalents"]. / Mise au point sur certaines formes électrocardiographiques atypiques du syndrome coronarien aigu - « Équivalents STEMI ¼.

The diagnosis of acute coronary syndrome with ST segment elevation (STEMI) is based on clinical symptoms suggestive of acute myocardial ischemia and precise ECG criteria. STEMI is due to an acute occlusion or subocclusion of a coronary artery, generating a transmural ischaemia, requiring coronary angiography with urgent coronary revascularization. However, some authors consider the current STEMI ECG criteria to be too restrictive: up to 30 % of patients who do not meet these criteria present with critical coronary artery stenosis or acute coronary occlusion. Atypical electrocardiographic patterns, known as "STEMI equivalents", can be found in some cases and justify a rapid cardiological evaluation. We present a pragmatic review of five STEMI equivalents.

Le diagnostic de syndrome coronarien aigu avec sus-décalage du segment ST (ST-Elevation Myocardial Infarction (STEMI)) est basé sur une clinique évocatrice d'une ischémie myocardique et des critères ECG précis. Le STEMI est le reflet d'une (sub)occlusion aiguë d'une artère coronaire engendrant une ischémie transmurale, nécessitant une coronarographie avec un geste de revascularisation en urgence. Certains auteurs considèrent les critères ECG actuels du STEMI comme étant trop restrictifs : jusqu'à 30 % des patients ne remplissant pas ces critères présenteraient une sténose coronarienne critique ou une occlusion coronarienne aiguë. Des aspects électrocardiographiques atypiques, dits « équivalents STEMI ¼, peuvent être mis en évidence dans certains cas et justifient une prise en charge cardiologique rapide. Nous présentons une revue pragmatique de cinq équivalents STEMI.

[Epicardial adipose tissue and atrial fibrillation]. / Tissu adipeux épicardique et fibrillation auriculaire.

Atrial fibrillation (AF) is the most common arrhythmia encountered in adults; it is associated with a significant morbidity and mortality. Obesity is a risk factor contributing to AF occurrence. Recently, interest has focused on epicardial adipose tissue (EAT), defined as a fatty deposit located between the epicardium and the visceral pericardium. Its characteristics are distinct from classic adipose deposits: it infiltrates the epicardial myocardium and secretes cytokines, which modulate cardiomyocyte electrophysiology and cardiac remodeling. Different studies show that EAT can be an independent risk factor for AF and that EAT thickness, as measured by CT or MRI, could predict the presence, severity and recurrence of AF.

La fibrillation auriculaire (FA) est l'arythmie la plus fréquemment rencontrée chez l'adulte ; elle est associée à une morbi-mortalité importante. L'obésité est un facteur de risque contribuant à sa survenue. Récemment, l'intérêt s'est porté sur le tissu adipeux épicardique (TAE), défini comme un dépôt adipeux situé entre l'épicarde et le péricarde viscéral. Ses caractéristiques sont distinctes des dépôts adipeux classiques : il infiltre le myocarde épicardique et sécrète des cytokines modulant l'électrophysiologie des cardiomyocytes et provoquant un remodelage fibro-adipeux cardiaque. Différentes études montrent que le TAE peut être un facteur de risque indépendant de survenue de FA. L'épaisseur du TAE mesurée par CT-scan ou par IRM pourrait être utilisée comme facteur prédictif de la présence, de la gravité et de la récidive de FA.

[Cardiology]. / Cardiologie.

Significant advances have been made in 2021 in the areas of interventional cardiology, heart failure, cardiac imaging, electrophysiology and congenital heart disease. In addition to improving the screening, diagnosis and management of many heart diseases, these advances will change our daily practice. Moreover, the European Society of Cardiology has updated its guidelines on heart failure, valve disease, cardiac pacing and cardiovascular disease prevention. As in previous years, members of the Cardiology division of Lausanne University Hospital (CHUV) came together to select and present to you the papers that they considered to be the most important of the past year.

De nombreux progrès ont été réalisés en 2021 dans les domaines de la cardiologie interventionnelle, de l'insuffisance cardiaque, de l'imagerie cardiaque, de l'électrophysiologie et des cardiopathies congénitales. En plus d'améliorer le dépistage, le diagnostic et la prise en charge de nombreuses cardiopathies, ces avancées vont faire évoluer notre pratique quotidienne. Par ailleurs, la Société européenne de cardiologie a mis à jour ses recommandations portant sur l'insuffisance cardiaque, les valvulopathies, la stimulation cardiaque et la prévention des maladies cardiovasculaires. Comme les années précédentes, les membres du Service de cardiologie du CHUV se sont réunis pour sélectionner et vous présenter les travaux qui leur ont semblé être les plus importants de l'année écoulée.

Myocardial extracellular volume by T1 mapping: a new marker of arrhythmia in mitral valve prolapse.

OBJECTIVES: We aimed to evaluate the relationship between mitral annular disjunction (MAD) severity and myocardial interstitial fibrosis at the left ventricular (LV) base in patients with mitral valve prolapse (MVP), and to assess the association between severity of interstitial fibrosis and the occurrence of ventricular arrhythmic events. BACKGROUND: In MVP, MAD has been associated with myocardial replacement fibrosis and arrhythmia, but the importance of interstitial fibrosis remains unknown. METHODS: In this retrospective study, 30 patients with MVP and MAD (MVP-MAD) underwent cardiovascular magnetic resonance (CMR) with assessment of MAD length, late gadolinium enhancement (LGE), and basal segments myocardial extracellular volume (ECVsyn). The control group included 14 patients with mitral regurgitation (MR) but no MAD (MR-NoMAD) and 10 patients with normal CMR (NoMR-NoMAD). Fifteen MVP-MAD patients underwent 24 h-Holter monitoring. RESULTS: LGE was observed in 47% of MVP-MAD patients and was absent in all controls. ECVsyn was higher in MVP-MAD (30 ± 3% vs 24 ± 3% MR-NoMAD, p < 0.001 and vs 24 ± 2% NoMR-NoMAD, p < 0.001), even in MVP-MAD patients without LGE (29 ± 3% vs 24 ± 3%, p < 0.001 and vs 24 ± 2%, p < 0.001, respectively). MAD length correlated with ECVsyn (rho = 0.61, p < 0.001), but not with LGE extent. Four patients had history of out-of-hospital cardiac arrest; LGE and ECVsyn were equally performant to identify those high-risk patients, area under the receiver operating characteristic (ROC) curve 0.81 vs 0.83, p = 0.84). Among patients with Holter, 87% had complex ventricular arrhythmia. ECVsyn was above the cut-off value in all while only 53% had LGE. CONCLUSION: Increase in ECVsyn, a marker of interstitial fibrosis, occurs in MVP-MAD even in the absence of LGE, and was correlated with MAD length and increased risk of out-of-hospital cardiac arrest. ECV should be includedin the CMR examination of MVP patients in an effort to better assess fibrous remodelling as it may provide additional value beyond the assessment of LGE in the arrhythmic risk stratification.

[The year in cardiology : 2018]. / Cardiologie.

This review article provides a broad overview of the novelties in cardiology in 2018. Advances in interventional cardiology and cardiovascular prevention, heart failure, electrophysiology and non-invasive cardiovascular imaging have provided important new insights in the pathophysiology, diagnosis and treatment of ischemic and valvular heart disease, heart failure, rhythm disorders and cardiomyopathies. This article provides an overview of the most relevant articles published in 2018.

L'année 2018 a été riche en nouveautés dans les domaines de la cardiologie interventionnelle, de l'insuffisance cardiaque, de l'électrophysiologie et de l'imagerie cardiaque. Les progrès dans ces domaines respectifs ont fourni de nouveaux outils pour le diagnostic et le traitement des cardiopathies ischémiques et valvulaires, de l'insuffisance cardiaque à fraction d'éjection réduite ou préservée, des troubles du rythme et des cardiomyopathies. Cet article fournit un aperçu des articles les plus pertinents publiés en 2018.

The influence of cardiac arrhythmias on the detection of heartbeats in the photoplethysmogram: benchmarking open-source algorithms.

Objective.Cardiac arrhythmias are a leading cause of mortality worldwide. Wearable devices based on photoplethysmography give the opportunity to screen large populations, hence allowing for an earlier detection of pathological rhythms that might reduce the risks of complications and medical costs. While most of beat detection algorithms have been evaluated on normal sinus rhythm or atrial fibrillation recordings, the performance of these algorithms in patients with other cardiac arrhythmias, such as ventricular tachycardia or bigeminy, remain unknown to date.Approach. ThePPG-beatsopen-source framework, developed by Charlton and colleagues, evaluates the performance of the beat detectors namedQPPG,MSPTDandABDamong others. We applied thePPG-beatsframework on two newly acquired datasets, one containing seven different types of cardiac arrhythmia in hospital settings, and another dataset including two cardiac arrhythmias in ambulatory settings.Main Results. In a clinical setting, theQPPGbeat detector performed best on atrial fibrillation (with a medianF1score of 94.4%), atrial flutter (95.2%), atrial tachycardia (87.0%), sinus rhythm (97.7%), ventricular tachycardia (83.9%) and was ranked 2nd for bigeminy (75.7%) behindABDdetector (76.1%). In an ambulatory setting, theMSPTDbeat detector performed best on normal sinus rhythm (94.6%), and theQPPGdetector on atrial fibrillation (91.6%) and bigeminy (80.0%).Significance. Overall, the PPG beat detectorsQPPG,MSPTDandABDconsistently achieved higher performances than other detectors. However, the detection of beats from wrist-PPG signals is compromised in presence of bigeminy or ventricular tachycardia.

Conduction System Pacing versus Conventional Biventricular Pacing for Cardiac Resynchronization Therapy: Where Are We Heading?

Over the last few years, pacing of the conduction system (CSP) has emerged as the new standard pacing modality for bradycardia indications, allowing a more physiological ventricular activation compared to conventional right ventricular pacing. CSP has also emerged as an alternative modality to conventional biventricular pacing for the delivery of cardiac resynchronization therapy (CRT) in heart failure patients. However, if the initial clinical data seem to support this new physiological-based approach to CRT, the lack of large randomized studies confirming these preliminary results prevents CSP from being used routinely in clinical practice. Furthermore, concerns are still present regarding the long-term performance of pacing leads when employed for CSP, as well as their extractability. In this review article, we provide the state-of-the-art of CSP as an alternative to biventricular pacing for CRT delivery in heart failure patients. In particular, we describe the physiological concepts supporting this approach and we discuss the future perspectives of CSP in this context according to the implant techniques (His bundle pacing and left bundle branch area pacing) and the clinical data published so far.

Case report: First-in-human combined low-dose whole-heart irradiation and high-dose stereotactic arrhythmia radioablation for immunosuppressive refractory cardiac sarcoidosis and ventricular tachycardia.

Background: Cardiac sarcoidosis is associated with heart failure, conduction abnormalities, and life-threatening arrhythmias including ventricular tachycardia (VT). Radiotherapy has been suggested as a treatment for extra-cardiac sarcoidosis in patients refractory to immunomodulatory treatment. Methods: The effectiveness and safety of low-dose whole-heart radiotherapy for therapy refractory cardiac sarcoidosis were evaluated in a pre- and post-intervention case report comparing the 54 months before and after treatment. Immunomodulatory low-dose whole-heart irradiation as sarcoidosis treatment consisted of a 2 × 2 Gy scheme. Additionally, high-dose single-fraction stereotactic arrhythmia radioablation of 1 × 20 Gy was applied to the pro-arrhythmic region to manage the ventricular tachycardia episodes. Cardiac sarcoidosis disease activity was measured by hypermetabolic areas on repeated fluorodeoxyglucose ([18F]FDG)-PET/computed tomography (CT) scans and by evaluating changes in ventricular tachycardia episodes before and after treatment. Results: One patient with therapy refractory progressive cardiac sarcoidosis and recurrent ventricular tachycardia was treated. The cardiac sarcoidosis disease activity showed a durable regression of inflammatory disease activity from 3 months onwards. The [18F]FDG-PET/CT scan at 54 months did not show any signs of active cardiac sarcoidosis, and a state of remission was achieved. The number of sustained VT episodes was reduced by 95%. We observed that the development of moderate aortic valve regurgitation was likely irradiation-related. No other irradiation-related adverse events occurred, and the left ventricular ejection fraction remained stable. Conclusion: We report here for the first time on the beneficial and lasting effects of combined immunomodulatory low-dose whole-heart radiotherapy and high-dose stereotactic arrhythmia radioablation in a patient with therapy refractory cardiac sarcoidosis and recurrent VT.

New Insights in Central Venous Disorders. The Role of Transvenous Lead Extractions.

Over the last decades, the implementation of new technology in cardiac pacemakers and defibrillators as well as the increasing life expectancy have been associated with a higher incidence of transvenous lead complications over time. Variable degrees of venous stenosis at the level of the subclavian vein, the innominate trunk and the superior vena cava are reported in up to 50% of implanted patients. Importantly, the number of implanted leads seems to be the main risk factor for such complications. Extraction of abandoned or dysfunctional leads is a potential solution to overcome venous stenosis in case of device upgrades requiring additional leads, but also, in addition to venous angioplasty and stenting, to reduce symptoms related to the venous stenosis itself, i.e., the superior vena cava syndrome. This review explores the role of transvenous lead extraction procedures as therapeutical option in case of central venous disorders related to transvenous cardiac leads. We also describe the different extraction techniques available and other clinical indications for lead extractions such as lead infections. Finally, we discuss the alternative therapeutic options for cardiac stimulation or defibrillation in case of chronic venous occlusions that preclude the implant of conventional transvenous cardiac devices.

Corrigendum: Yield of the electrophysiological study in patients with new-onset left bundle branch block after transcathether aortic valve replacement: The PR interval matters.

[This corrects the article DOI: 10.3389/fcvm.2022.910693.].

Familial Recurrence Patterns in Congenitally Corrected Transposition of the Great Arteries: An International Study.

BACKGROUND: Congenitally corrected transposition of the great arteries (ccTGA) is a rare disease of unknown cause. We aimed to better understand familial recurrence patterns. METHODS: An international, multicentre, retrospective cohort study was conducted in 29 tertiary hospitals in 6 countries between 1990 and 2018, entailing investigation of 1043 unrelated ccTGA probands. RESULTS: Laterality defects and atrioventricular block at diagnosis were observed in 29.9% and 9.3%, respectively. ccTGA was associated with primary ciliary dyskinesia in 11 patients. Parental consanguinity was noted in 3.4% cases. A congenital heart defect was diagnosed in 81 relatives from 69 families, 58% of them being first-degree relatives, including 28 siblings. The most prevalent defects in relatives were dextro-transposition of the great arteries (28.4%), laterality defects (13.6%), and ccTGA (11.1%); 36 new familial clusters were described, including 8 pedigrees with concordant familial aggregation of ccTGA, 19 pedigrees with familial co-segregation of ccTGA and dextro-transposition of the great arteries, and 9 familial co-segregation of ccTGA and laterality defects. In one family co-segregation of ccTGA, dextro-transposition of the great arteries and heterotaxy syndrome in 3 distinct relatives was found. In another family, twins both displayed ccTGA and primary ciliary dyskinesia. CONCLUSIONS: ccTGA is not always a sporadic congenital heart defect. Familial clusters as well as evidence of an association between ccTGA, dextro-transposition of the great arteries, laterality defects and in some cases primary ciliary dyskinesia, strongly suggest a common pathogenetic pathway involving laterality genes in the pathophysiology of ccTGA.

New developments in catheter ablation for patients with congenital heart disease.

Introduction: There are numerous challenges to catheter ablation in patients with congenital heart disease (CHD), including access to cardiac chambers, distorted anatomies, displaced conduction systems, multiple and/or complex arrhythmia substrates, and excessively thickened walls, or interposed material. Areas covered: Herein, we review recent developments in catheter ablation strategies for patients with CHD that are helpful in addressing these challenges. Expert opinion: Remote magnetic navigation overcomes many challenges associated with vascular obstructions, chamber access, and catheter contact. Patients with CHD may benefit from a range of ablation catheter technologies, including irrigated-tip and contact-force radiofrequency ablation and focal and balloon cryoablation. High-density mapping, along with advances in multipolar catheters and interpolation algorithms, is contributing to new mechanistic insights into complex arrhythmias. Ripple mapping allows the activation wave front to be tracked visually without prior assignment of local activation times or window of interest, and without interpolations of unmapped regions. There is growing interest in measuring conduction velocities to identify arrhythmogenic substrates. Noninvasive mapping with a multielectrode-embedded vest allows prolonged bedside monitoring, which is of particular interest in those with non-sustained or multiple arrhythmias. Further studies are required to assess the role of radiofrequency needle catheters and stereotactic radiotherapy in patients with CHD.

Dynamics of Intraprocedural Dominant Frequency Identifies Ablation Outcome in Persistent Atrial Fibrillation.

Background: The role of dominant frequency (DF) in tracking the efficiency of a stepwise catheter ablation (step-CA) in persistent atrial fibrillation (peAF) remains poorly studied. We hypothesized that the DF time-course during step-CA displays divergent patterns between patients in whom a step-CA successfully restores long-term sinus rhythm (SR) and those with recurrence. Methods: This study involved 40 consecutive patients who underwent a step-CA for peAF (sustained duration 19 ± 11 months). Dominant frequency was computed on electrograms recorded from the right and left atrial appendages (RAA; LAA) and the coronary sinus before and during the step-CA synchronously to the 12-lead ECG. Dominant frequency was defined as the highest peak within the power spectrum. Results: Persistent atrial fibrillation was terminated by a step-CA in 28 patients [left-terminated (LT)], whereas 12 patients remaining in AF after ablation [not left-terminated (NLT)] were cardioverted. Over a mean follow-up of 34 ± 14 months, all NLT patients had a recurrence. Among the 28 LT patients, 20 had a recurrence, while 8 remained in SR throughout follow-up. The RAA and V1 DF had the best predictive values of the procedural failure to terminate AF (area under the curve; AUC 0.84, p < 0.05). A decision tree model including a decrease in LAA DF ≥ 6.61% during the first 20 min following pulmonary vein isolation (PVI) and a baseline RAA DF <5.6 Hz predicted long-term SR restoration with a sensitivity of 83% and a specificity of 93% (p < 0.05). Conclusion: This study found that high baseline DF values are predictive of unfavorable ablation outcomes. The reduction of the LAA DF at early ablation steps following PVI is associated with procedural AF termination and long-term SR maintenance.

Efficiency of the RADPAD Surgical Cap in Reducing Brain Exposure During Pacemaker and Defibrillator Implantation.

OBJECTIVES: This study sought to investigate the RADPAD No Brainer (Worldwide Innovation and Technologies, Overland Park, Kansas) efficiency in reducing brain exposure to scattered radiation. BACKGROUND: Cranial radioprotective caps such as the RADPAD No Brainer are being marketed as devices that significantly reduce operator's brain exposure to scattered radiation. However, the efficiency of the RADPAD No Brainer in reducing brain exposure in clinical practice remains unknown to date. METHODS: Five electrophysiologists performing device implantations over a 2-month period wore the RADPAD cap with 2 strips of 11 thermoluminescent dosimeter pellets covering the front head above and under the shielded cap. Phantom measurements and Monte Carlo simulations were performed to further investigate brain dose distribution. RESULTS: Our study showed that the right half of the operators' front head was the most exposed region during left subpectoral device implantation; the RADPAD cap attenuated the skin front-head exposure but provided no protection to the brain. The exposure of the anterior part of the brain was decreased by a factor of 4.5 compared with the front-head skin value thanks to the skull. The RADPAD cap worn as a protruding horizontal plane, however, reduced brain exposure by a factor of 1.7 (interquartile range: 1.3 to 1.9). CONCLUSIONS: During device implantation, the RADPAD No Brainer decreased the skin front head exposure but had no impact on brain dose distribution. The RADPAD No Brainer worn as a horizontal plane worn around the neck reduces brain exposure and confirms that the exposure comes from upward scattered radiation.

Severe and uniform bi-atrial remodeling measured by dominant frequency analysis in persistent atrial fibrillation unresponsive to ablation.

BACKGROUND: High values of ECG and intracardiac dominant frequency (DF) are indicative of significant atrial remodeling in persistent atrial fibrillation (peAF). We hypothesized that patients with peAF unresponsive to ablation display higher ECG and intracardiac DFs than those remaining in sinus rhythm (SR) on the long term. METHODS: Forty consecutive patients underwent stepwise ablation for peAF (sustained duration 19 ± 11 months). Electrograms were recorded before ablation at 13 left atrium (LA) sites and at the right atrial appendage (RAA) and coronary sinus (CS) synchronously to the ECG. DF was defined as the highest peak within the power spectrum. RESULTS: peAF was terminated within the LA in 28 patients (left-terminated [LT]), whereas 12 patients remaining in AF after ablation (not left-terminated [NLT]) were cardioverted. Over a mean follow-up of 34 ± 14 months, all 12 NLT patients had a recurrence. Of the LT patients, 71% had a recurrence (20/28, LT_Rec), while 29% remained in SR throughout the follow-up (8/28, LT_SR). DF values and correlations between pairs of LA appendage (LAA), RAA, and CS DFs showed distinctive patterns among the subgroups. The NLT subgroup displayed the highest ECG and intracardiac DFs, with strong intragroup homogeneity between pairs of CS and LAA DFs, and to a lesser extent between pairs of CS and RAA DFs. Conversely, the LT_SR subgroup showed the lowest DFs, with significant intragroup heterogeneity between pairs of CS and both LAA and RAA DFs. CONCLUSIONS: Patients with peAF unresponsive to ablation show high surface and intracardiac DFs indicative of severe and uniform bi-atrial remodeling.

Maximal Pre-Excitation Based Algorithm for Localization of Manifest Accessory Pathways in Adults.

OBJECTIVES: This study evaluated a new algorithm relying on maximal pre-excitation. BACKGROUND: Prior knowledge of accessory pathway (AP) location facilitates an individual ablation strategy. Delta-wave analysis on a 12-lead electrocardiogram is recognized as crucial for predicting ablation site, but can be ambiguous at basal state. METHODS: An algorithm based on maximal pre-excitation, as induced by atrial pacing during an electrophysiological study, was initially developed in 132 patients with a single manifest AP. The maximally pre-excited QRS features included the global polarity in lead V1 (step 1), inferior leads (step 2), and leads V3 or I (step 3), as well as the morphology in lead II (step 4). Three investigators prospectively tested the new algorithm in 207 consecutive patients by comparing its efficacy to a control algorithm relying on basal pre-excitation. RESULTS: The accuracy, defined as the percent of patients with an exact prediction of AP location, was significantly greater with the new algorithm (90% vs. 63%; p < 0.001). The reproducibility, defined as the level of agreement between investigators in determining AP location, was excellent (κ > 0.75; p < 0.05) with the new algorithm and fair (0.40 < κ < 0.75; p < 0.05) with the control algorithm. CONCLUSIONS: An algorithm based on maximal pre-excitation allows accurate and reproducible localization of manifest APs. When ablation is indicated, the analysis of maximal pre-excitation is a sensible approach for giving a head start in endocardial mapping.