Electroanatomic Mapping Research Articles

Radiofrequency ablation vs. cryoablation for pediatric atrioventricular nodal reentrant tachycardia in the era of three-dimensional electroanatomical mapping

Radiofrequency ablation vs. cryoablation for pediatric atrioventricular nodal reentrant tachycardia in the era of three-dimensional electroanatomical mapping

Relationship between left atrial sphericity assessed by echocardiography and left atrial fibrosis in patients undergoing ablation for atrial fibrillation

Abstract Purpose The left atrial (LA) shape is the novel marker characterizing LA myopathy. Increased LA sphericity measured in magnetic resonance was shown to have relationship with LA fibrosis. Data on LA sphericity measured in echocardiography are sparse. The aim was to assess LA sphericity in relation to degree of LA fibrosis derived from electroanatomical mapping (EAM) in patients with atrial fibrillation (AF). Methods Patients (pts) with AF were studied with TTE before first ablation during sinus rhythm. LA sphericity index (LASi) was calculated as the ratio of LA maximum volume (area-length method) to LA volume of sphere structured by maximum LA length from a 4- and 2-chamber views. The EAM of LA was performed using Carto System. Low amplitude potentials area (LAPA) was quantitatively analysed and expressed as a percentage of LA surface using the cut-off <0.05 mV to detect sites of fibrosis. LA parameters were compared between mild (LAPA<10%), moderate (LAPA 10-40%) and extensive (LAPA>40%) degree of LA fibrosis. Results Study group consisted of 51 pts (74,5 % males, mean age 56±10 years). The median [Q1-Q3] LA volume index (LAVi) was 37.1 [28.9 – 52.6] mL/m². The median [Q1-Q3] LASi was 0.82 [0.71 – 1.06]. The LAPA ranged from 2 to 77 percent of LA surface. The Spearman’s correlation analysis showed a significant correlation between LASi and LAPA (0.59, p<0.001). Increased LA sphericity was observed in LAPA≥10% whereas increased LAVi in LAPA≥40% subgroup (table). Conclusion The LASi derived from TTE correlates well with the extent of LAPA, thus might be a simple and useful parameter of LA geometric remodeling associated with increased LA fibrosis. LA geometry in relation to fibrosis

Transhepatic venous access for catheter ablation of right and left side atrial arrhythmias in adults: challenges and outcomes.

Electrophysiologic (EP) procedures are typically performed via the femoral venous system, but in some patients, the inferior vena cava (IVC) is unavailable. The hepatic vein has emerged as a viable alternative to femoral access, providing an inferior route that accommodates large sheaths required for better catheter manipulation. Although the percutaneous transhepatic approach has been used successfully in the pediatric population, its use in adults is scarce, with a complication rate of approximately 5%. Three patients with limited venous access were referred for ablation between 2018 and 2021. The percutaneous transhepatic access approach provided good support for the EP study, electro-anatomical mapping, and effective radiofrequency ablation of right and left-side arrhythmias. No significant complications were documented, and all patients were discharged within 48 hours of the procedure. At follow-up, all patients had excellent arrhythmia control without significant adverse events. Percutaneous transhepatic access is a feasible and safe alternative to femoral venous access for EP procedures in adult patients with limited venous access.

Comparative analysis of left atrial size and appendage morphology in paroxysmal and persistent atrial fibrillation patients.

Pulmonary vein isolation (PVI) is effective in treating atrial fibrillation (AF), but outcomes are worse for persistent AF (persAF) patients than paroxysmal AF (PAF) patients. The study aimed to identify differences in left atrial (LA) and left atrial appendage (LAA) anatomy in different AF types. In a single-center observational study, a blinded retrospective analysis of preprocedural cardiac computed tomography angiography (CCTA) images was performed. The study evaluated the dimensions of the LA and pulmonary veins (PV), as well as the size and morphology of the LAA using a 3D electroanatomical mapping system. Between 2012 and 2016, a total of 1103 patients underwent second-generation cryoballoon PVI. Of these, 725 patients (65.7%) had CCTA available, and 473 of these (65.2%) had sufficient quality for measurements. The mean age of the patients was 66.3 ± 9.5 years, and PAF was present in 277 (58.6%) participants. The study found that in persAF patients, LA dimensions such as LA volume [mL] (108; 125; p < .001) or PV ostial dimensions were significantly larger than in those with PAF. LAA volume [mL] (8.3; 9.2; p = .005) and LAA ostial area [mm2] (325; 353; p = .01) were enlarged in persAF. There were no significant differences regarding LAA morphology, with the overall distribution being "windsock" (51%), "chicken-wing" (20%), "cauliflower" (15%), and "cactus" (13%). Compared to PAF, persAF patients had significantly larger LA as well as LAA dimensions. LAA morphological types were distributed equally in both groups suggesting that LAA morphology may not be associated with the underlying AF type.

An approach to fluoroless radiofrequency atrial fibrillation ablation

Atrial fibrillation is the most prevalent arrhythmia with a lifetime risk of nearly 30%. It can be associated with reduced quality of life and complications such as heart failure and stroke. Pulmonary vein isolation (PVI) is the most effective treatment for rhythm control. It has initially been performed with fluoroscopic catheter guiding. The advent of three-dimensional (3D) electro-anatomical mapping has significantly reduced the need for fluoroscopy. More recently, intracardiac echography (ICE) techniques have been used to eliminate the need for x-rays. Additional advantages include providing electrophysiology lab personnel with a lead-free working environment and avoiding radiation exposure for both patients and physicians. ICE may also enhance the safety of the procedure by enabling a safe trans-septal puncture and the early recognition of cardiac tamponade. In this article, we present our approach to fluoroless radiofrequency PVI using ICE and 3D electro-anatomical mapping.

A catheter ablation case of confluent inferior and left superior pulmonary veins: a rare pulmonary vein variation.

Pulmonary vein (PV) variations are commonly detected by preoperative imaging modalities in catheter ablation for atrial fibrillation. However, rare variations that have not been previously reported exist. The present case is the first reported instance of three PVs originating from a common trunk. Contrast-enhanced cardiac computed tomography revealed that the left superior, left inferior, and right inferior PVs originated from the common trunk. Additionally, 3-dimensional electroanatomical mapping revealed interesting findings, showing that the three PVs and their common trunk were scarred areas prior to catheter ablation. The rare common PV may have no arrhythmogenic substrate in the PV antrum or common trunk.

A tailored substrate-based approach using focal pulsed field catheter ablation in patients with atrial fibrillation and advanced atrial substrate: Procedural data and 6-months success rates.

Focal pulsed-field ablation (F-PFA) integrated in electroanatomical mapping (EAM) systems allows tailored lesion sets in patients with atrial fibrillation (AF). To determine feasibility, safety and 6-months outcome of F-PFA for a tailored substrate-based catheter ablation (CA) approach in patients with AF and advanced atrial substrate. Consecutive patients with AF and advanced atrial substrate treated by a F-PFA system (Cardiofocus) through contact-force sensing catheters integrated in EAM systems were prospectively enrolled. The tailored substrate-based CA approach included isolation of all pulmonary veins (PVI) with wide area circumferential ablation, posterior wall isolation (PWI), mitral anterior line and cavo-tricuspid isthmus (CTI) ablation, according to substrate. At 6 months, feasibility, arrhythmia recurrence and safety were evaluated. In 83 patients (33% female, indexed left atrial volume: 44±15ml/m2, 80% persistent AF or atrial flutter (AFl), 57% re-do procedures), successful de-novo PVI was performed in 36 patients and PV reisolation in 30 patients. Mitral anterior line was performed in 19 patients with atypical AFl or anterior low voltage areas; PWI was performed in 38 patients with low voltage areas or evoked delayed electrograms during premature atrial extrastimuli; CTI was performed in 24 patients with typical AFl. Median procedural and fluoroscopy times were 115 and 7 minutes, respectively. No complications occurred. At 6 months, arrhythmia recurrence occurred in 30/83 patients (21 AF; 9 atypical AFl). Tailored substrate-based F-PFA in patients with AF and advanced atrial substrate is safe and effective. Acute procedural success was 100% with 64% freedom from arrhythmias after 6 months.

Whole-Heart Histological and CMR Validation of Electroanatomic Mappingby Multielectrode Catheters inan Ovine Model.

Accurate electroanatomic mapping is critical for identifying scar and the long-term success of ventricular tachycardia ablation. This study sought to determine the accuracy of multielectrode mapping (MEM) catheters to identify scar on cardiac magnetic resonance (CMR) and histopathology. In an ovine model of myocardial infarction, we examined the effect of electrode size, spacing, and mapping rhythm on scar identification compared to CMR and histopathology using 5 multielectrode mapping catheters. We co-registered electroanatomic mapping, CMR, and histopathology for comparison. Catheter-specific voltage thresholds were identified based on underlying amounts of normal myocardium on transmural histology biopsies. Ten animals were included: 6 with anteroseptal myocardial infarction and 4 control animals. A total of 419,597 points were manually reviewed across the catheters, with 315,487 points used in the analysis. There were minimal differences in bipolar and unipolar voltages, scar areas, and abnormal electrograms between catheters and between rhythms. Catheter-specific bipolar and unipolar voltage thresholds for normal myocardium were High-Density Grid >2.78mV and >6.19mV, DuoDecapolar >2.22mV and >6.05mV, PentaRay >1.66mV and >5.35mV, Decanav >1.36mV and >4.75mV, Orion >1.21mV and >6.05mV, respectively. Catheter-specific bipolar thresholds improved the accuracy for detecting endo-mid myocardial scar on CMR by 1.8%-15.6% and catheter-specific unipolar thresholds improved the accuracy in the mid-epicardial layers by 25.3%-81.1%. Minimal differences were observed in scar detection and electrogram markers between commercially available multielectrode mapping catheters and differing wave fronts. Compared to traditional voltage criteria for bipolar and unipolar scar, catheter-specific thresholds markedly improved accuracy for delineating scar on CMR.

Conduction system pacing using electro-anatomical mapping-guided system vs. fluoroscopy: a systematic review, meta-analysis and economic evaluation

Electro-anatomical mapping (EAM) system has been shown as an alternative procedure to fluoroscopy for conduction system pacing (CSP) in patients with severe bradyarrhythmia, however its beneficial and harmful effects has not been assessed in a systematic review (SR). We sought to assess their safety, effectiveness and cost-effectiveness. A SR of the available scientific literature was conducted on the safety, effectiveness, and cost-effectiveness of CSP using EAM system vs. fluoroscopy in patients with severe bradyarrhythmia. A partial economic evaluation was carried out to compare the costs of both strategies from the perspective of the Spanish National Health System. A budget impact analysis was also conducted with a five-year horizon. Seven comparative observational studies (N = 231), analyzing the use of EAM vs. fluoroscopy were selected. Statistically significant differences were observed in total fluoroscopy time: −9.87 min (95%CI:−14.20, −5.53, p &amp;lt; 0.01; I2 = 95%; k = 7; n = 231); His-lead fluoroscopic time: −8.08 min (95%CI:−10.36, −5.81, p &amp;lt; 0.01; I2 = 0%; k = 2; n = 50); and His-lead radiation dose: −17.21 mGy (95%CI:−24.08, −10.34, p &amp;lt; 0.01; k = 1; n = 20). No differences in total fluoroscopy dose, successful procedure or safety were found. The use of EAM represents an increase of EUR 1,397.81 per patient and a net budget impact of EUR 1.63 million. EAM is a valuable alternative for patients who should not be exposed to ionizing radiation with similar effectiveness and safety than fluoroscopy. However, the inclusion of EAM systems, for the indication under study, in routine clinical practice would mean an increase in costs for the Spanish National Health System.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=421072, identifier (CRD42023421072).

Effect analysis of radiofrequency catheter ablation in the treatment of 7 children with atrial tachycardia-induced cardiomyopathy

BackgroundTachycardia-induced cardiomyopathy refers to changes in cardiac structure and function that result from rapid arrhythmia and can manifest as a continuous or recurrent event. Cardiomyopathy induced by atrial tachycardia is typically reversible if the arrhythmia is effectively controlled. There are few literature reports of atrial tachycardia-induced cardiomyopathy in children, and fewer cases have been effectively treated by radiofrequency catheter ablation in children.Objectivewe conducted a clinical summary of 7 cases of atrial tachycardia-induced cardiomyopathy in children in Wuhan Children’s Hospital to investigate the effectiveness and safety of radiofrequency catheter ablation for atrial tachycardia-induced cardiomyopathy.MethodsA total of 7 children (4 girls and 3 boys) diagnosed with atrial tachycardia-induced cardiomyopathy and admitted to Wuhan Children’s Hospital from January 2017 to April 2024 were selected. An intracardiac electrophysiological study was conducted on all 7 children to verify the origin of the atrial tachycardia and the presence of decreased cardiac function. All children were followed up for a period ranging from 2 to 12 months after RFCA or atrial appendectomy. During this follow-up, left ventricular end-diastolic diameter and left ventricular ejection fraction were monitored.ResultsThe age range was 3.6 to 13 years and the median age was 11.2 years. The weight range was from 15 to 92 kg, the average weight was 34 kg. The results of the intracardiac electrophysiological study of the 7 cases showed that the origin came from the right pulmonary vein in 2 cases, from the left pulmonary vein in 2 cases, from the left atrial appendage in one case, and from the right atrial appendage in 2 cases. Four cases of tachycardia-induced cardiomyopathy originating in the left and right pulmonary veins were successfully eliminated by radiofrequency catheter ablation (RFCA). The foci of atrial tachycardia were located in the atrial appendages of three children. For two of them, after precise positioning by the atrium three-dimensional electroanatomic mapping system and performing RFCA, the atrial tachycardia briefly stopped for approximately 24 h before reoccurring, and atrial appendectomy was subsequently performed. Nevertheless, in the other child, whose focus of atrial tachycardia was in the right atrial appendage, the lesion was successfully eliminated by RFCA. After RFCA or in combination with atrial appendectomy, 6 children were followed for more than 1 year and 1 child for 2 months. All children had sinus rhythm. At the same time, the left ventricular ejection fraction after RFCA or combined atrial appendectomy was significantly increased in 7 cases, indicating statistical significance (P = 0.018)), but the left ventricular end-diastolic diameter was not statistically significant in the treatment (P = 0.203)).ConclusionsSustained atrial tachycardia can lead to the occurrence of cardiomyopathy such as cardiac enlargement and heart failure. RFCA and combined atrial appendectomy can effectively stop tachycardia, eliminate the mechanism of tachycardia, and allow complete recovery of cardiac function.

Long road to success. Endocardial radiofrequency ablation of septal hypertrophy using three-dimensional electroanatomic mapping guided by echocardiography in a patient with hypertrophic obstructive cardiomyopathy and severe aortic stenosis.

Long road to success. Endocardial radiofrequency ablation of septal hypertrophy using three-dimensional electroanatomic mapping guided by echocardiography in a patient with hypertrophic obstructive cardiomyopathy and severe aortic stenosis.

Personalized Heart Digital Twins Detect Substrate Abnormalities in Scar-Dependent Ventricular Tachycardia.

Current outcomes from catheter ablation for scar-dependent ventricular tachycardia (VT) are limited by high recurrence rates and long procedure durations. Personalized heart digital twin technology presents a noninvasive method of predicting critical substrate in VT, and its integration into clinical VT ablation offers a promising solution. The accuracy of the predictions of digital twins to detect invasive substrate abnormalities is unknown. We present the first prospective analysis of digital twin technology in predicting critical substrate abnormalities in VT. Heart digital twin models were created from 18 patients with scar-dependent VT undergoing catheter ablation. Contrast-enhanced cardiac magnetic resonance images were used to reconstruct finite-element meshes, onto which regional electrophysiological properties were applied. Rapid-pacing protocols were used to induce VTs and to define the VT circuits. Predicted optimum ablation sites to terminate all VTs in the models were identified. Invasive substrate mapping was performed, and the digital twins were merged with the electroanatomical map. Electrogram abnormalities and regions of conduction slowing were compared between digital twin-predicted sites and nonpredicted areas. Electrogram abnormalities were significantly more frequent in digital twin-predicted sites compared with nonpredicted sites (468/1029 [45.5%] versus 519/1611 [32.2%]; P<0.001). Electrogram duration was longer at predicted sites compared with nonpredicted sites (82.0±25.9 milliseconds versus 69.7±22.3 milliseconds; P<0.001). Digital twins correctly identified 21 of 26 (80.8%) deceleration zones seen on isochronal late activation mapping. Digital twin-predicted sites display a higher prevalence of abnormal and prolonged electrograms compared with nonpredicted sites and accurately identify regions of conduction slowing. Digital twin technology may help improve substrate-based VT ablation. URL: https://www.clinicaltrials.gov; Unique identifier: NCT04632394.

Technical standards for performing radiofrequency catheter ablation for atrial fibrillation: a series of consortium standards

Atrial fibrillation (AF) has emerged as a major global cardiovascular disease in the 21st century. In China, there are greater than 12 million patients with AF, and its incidence continues to rise. AF affects patients' quality of life and significantly increases the risks of mortality, stroke, heart failure, cognitive impairment, and dementia. In recent years, multiple clinical guidelines have expanded the indications for catheter ablation and raised its level of recommendation. Concurrently, there has been a rapid and sustained increase in the number of AF ablation procedures performed across China. Among these, radiofrequency catheter ablation remains the most used method. Consequently, the Chinese Heart Rhythm Society of the Chinese Society of Biomedical Engineering, in collaboration with 40 arrhythmia centers and 60 leading clinical experts specializing in AF catheter ablation, developed a comprehensive set of standards. These standards were developed based on extensive clinical experience accumulated in recent years and the latest national and international AF guidelines and consensus documents. They address five critical domains: periprocedural management, intra-atrial septal puncture, anatomical reconstruction and electroanatomic mapping, ablation, and complication identification and management. By providing a structured framework, these standards aim to guide AF catheter ablation practice, thereby enhancing procedural safety and efficacy.

Characterization and Localization of Focal Atrial Tachycardia in Patients With Adult Congenital Heart Disease.

In patients with structurally normal hearts, algorithms using surface electrocardiographic P-wave morphology are helpful to predict focal atrial tachycardia (FAT) location. However, these algorithms have not been formally assessed in patients with adult congenital heart disease (ACHD). This study sought to assess the efficacy of FAT-location prediction algorithms in an adult population of patients with ACHD. In this single-center retrospective cross-sectional study, FAT P-waves were classified as: 1) positive; 2)negative; 3) isoelectric; or 4) biphasic. FAT ablation sites identified by electroanatomic mapping were grouped by region: right atrium (RA), paraseptal (PS), and left atrium. Accuracy of P-wave classification criteria to predict FAT region were determined. Thirty FATs were assessed in 29 patients (mean age 47 ± 16 years, female 55%, and prior surgical repair in 83%): RA FAT sites-crista terminalis (n=14), Fontan baffle (n=3), nonseptal tricuspid annulus (n=1); PS FAT sites-PS tricuspid annulus (n=2), coronary sinus ostium (n=3), foramen ovale (n=1); and left atrial FAT sites-mitral annulus (n=2), right superior pulmonary vein (n=1), left atrial appendage (n=3). A negative or (±) P-wave in V1 had a 100% specificity for RA origin. Other P-wave morphologies in lead V1 poorly predicted atrial origin. All P-wave morphologies in lead aVL had low sensitivity and specificity for atrial origin. The vast majority of FATs observed in patients with ACHD originate from origins common to those with normal hearts rather than foci unique to ACHD. However, applying algorithms established in patients with normal hearts using P-wave morphology to localize FAT only variably predicts FAT origin in our cohort of ACHD patients.

Hospital readmissions following catheter ablation for atrial fibrillation with THERMOCOOL™ STSF/ THERMOCOOL™ ST catheter with CARTO™ 3 system versus TactiCath™ catheter with EnSite™ system.

Aim: Radiofrequency (RF) catheter ablation (CA) is a mainstay treatment for atrial fibrillation (AF). RF catheters with contact force (CF) sensing technology and electroanatomical mapping systems enable real-time assessment of catheter tip-tissue interface CF, facilitating individualized and precise CA. This study examined inpatient hospital readmissions in patients with AF treated with THERMOCOOL™ ST/ THERMOCOOL™ STSF catheter with the CARTO™ 3 System versus TactiCath™ catheter with the EnSite™ System. Materials & methods: Patients undergoing CA for AF between 1 July 2019 to 30 November 2021 were identified from the Premier Healthcare Database and grouped based on use of THERMOCOOL ST/STSF or TactiCath™. Study outcomes were all-cause, cardiovascular (CV)-, and AF-related inpatient readmission at 91-365-day post-CA. Inverse probability of treatment weighting of propensity scores balanced baseline patient, comorbidity and hospital characteristics. A weighted generalized estimating equation (GEE) model examined differences in readmission outcomes. Results: A total of 15,518 patients met inclusion criteria (THERMOCOOL ST/STSF, n=13,001; TactiCath™, n=2517). Patient characteristics were generally well-balanced after weighting. Patients treated with THERMOCOOL ST/STSF+CARTO 3 had a 20% lower likelihood of all-cause inpatient readmissions (7.8 vs 9.3%, chi-square p=0.041; odds ratio [OR]: 0.80, 95% confidence interval [CI]: 0.66-0.96, GEE p=0.019) and a 21% lower likelihood of CV-related inpatient readmission (5.2 vs 6.2%, chi-square p=0.133, OR: 0.79, 95% CI: 0.62-0.99, GEE p=0.043) in 91-365-days post-CA versus those treated with TactiCath™+ Ensite. No significant differences were observed for AF-related readmissions. Conclusion: Patients undergoing CA for AF treated with THERMOCOOL ST/STSF+CARTO 3 had a significantly lower risk of all-cause and CV-related inpatient hospital readmission versus those treated with TactiCath™+Ensite.

The Electroanatomic Volume of the Left Atrium as a Determinant of Recurrences in Patients with Atrial Fibrillation After Pulmonary Vein Isolation: A Prospective Study.

Background/Objectives: Catheter ablation for atrial fibrillation (AF) is a well-established therapeutic approach for maintaining sinus rhythm, though its efficacy remains suboptimal in certain patients. The left atrium (LA) volume, commonly assessed through transthoracic echocardiography (TTE), is a recognized predictor of AF recurrence after pulmonary vein isolation (PVI). However, the complex three-dimensional structure of the LA makes precise measurement challenging with traditional TTE techniques. Electroanatomic mapping (EAM) offers a more accurate evaluation of LA geometry and volume, which may enhance the prediction of ablation outcomes. Methods: This prospective study included 197 patients with AF who were referred for PVI to our center (Hospital Universitario Central de Asturias, Spain) between 2016 and 2020. All participants underwent pre-ablation TTE and EAM to assess the electric active volume (EAV) of the LA. Clinical follow-up included regular Holter monitoring and electrocardiograms to detect AF recurrences. Results: The mean age was 56.3 ± 9.67 years, and 34% had persistent AF. The mean LA volumes measured by TTE and the EAV by EAM were 62.86 ± 15.58 mL and 126.75 ± 43.35 mL, respectively, with a moderate positive correlation (r = 0.49, p < 0.001). AF recurrences were observed in 51.27% of patients over a 36 ± 15-month follow-up period. Cox regression analyses (univariate and multivariate), Kaplan-Meier curves and log-rank tests were used to illustrate freedom from atrial arrhythmia during follow-up. Both EAV by EAM and TTE volumes were significant predictors of AF recurrence in the univariate analysis (HR 1.002 [1.001-1.003], p = 0.033 and HR 1.001 [1.006-1.012], p < 0.01, respectively). Among clinical variables, persistent AF was significantly associated with a higher risk of recurrence (HR 1.17 [1.096-1.268], p = 0.02). Conclusions: EAV of the LA assessment by EAM demonstrates a significant correlation with TTE measurements and is a predictor of AF post-ablation recurrence. In patients selected for catheter ablation, EAV by EAM provides additional insights that could contribute to therapeutic decision-making and risk stratification of AF recurrences.

High-density mapping in catheter ablation for atrial fibrillation in Asia Pacific region: An observational study.

Few clinical studies of atrial fibrillation (AF) have focused on Asian patients; data are lacking on current mapping and ablation strategies in the Asia Pacific region (APAC). The HD Mapping Observational Study (NCT04022954) was designed to characterize electroanatomic mapping (EAM) with market-released high-density mapping (HDM) catheters in subjects with AF in APAC. Subjects undergoing HDM and indicated for radiofrequency ablation (RFA) to treat AF were prospectively enrolled in APAC. Data included mapping strategy and ablation targets. EAM was performed using one of two commercially available HDM catheters (Advisor™ HD Grid, Sensor Enabled™, Abbott [GRID] or Inquiry™ AFocus II™ Double Loop, Abbott [DL]). Procedure-related adverse events were collected. Two hundred subjects were enrolled at 15 centers: 164 with symptomatic paroxysmal (PAF) and 36 with symptomatic persistent (PersAF) AF for de novo ablation. GRID and DL were used in 186 and 14 cases, respectively. All subjects underwent voltage mapping, with conservative thresholds (low voltage ≤0.5 mV and very low voltage/electrical scar ≤0.1 mV) used in 60.2% and 35.4% of maps, respectively. Focal impulses, rotors, complex fractionated electrograms, and other substrate targets were each searched for in <3% of subjects. Median time to generate a map was 9.0 (Q1: 5.0, Q3: 13.0) minutes. Ablation strategy included pulmonary vein (PV) isolation in all, and non-PV triggers in 75/200 (37.5%) subjects. Five serious adverse events were reported. The study demonstrated an efficient strategy with the feasibility and safety of using HDM during AF ablation procedures in APAC.

Pulsed-field ablation of atrial fibrillation with a pentaspline catheter across National Health Service England centres

IntroductionPulsed-field ablation (PFA) is a novel modality for pulmonary vein isolation in patients with atrial fibrillation (AF). We describe the initial uptake and experience of PFA using a pentaspline catheter...

Catheter Ablation in Atrial Fibrillation: Recent Advances.

Atrial fibrillation (AF) is the leading cause of arrhythmia-related morbidity and mortality. Recurrent symptoms, hospitalizations, and cost burden to patients have necessitated treatments beyond antiarrhythmic drugs (AADs) for patients with AF. Catheter ablation has proven to be effective over medical therapy alone; however the recurrence rates for atrial tachyarrhythmias post-ablation remain significant, particularly in patients with persistent and long-standing persistent AF. Hence, new techniques for catheter ablation have arisen, such as non-thermal energy sources, novel catheters, electroanatomical mapping, and ablation of additional targets. In this review, we discuss the recent advances in the field of catheter ablation, including newer modalities for the prevention of adverse events and future perspectives.

Late Enhancement Computed Tomography for Left Atrial Fibrosis Imaging: A Pilot "Proof-of-Concept" Study.

Background/Objective: Left atrial (LA) fibrosis imaging improves the guidance of LA catheter ablation. Cardiac computed tomography (CT) may be a reasonable alternative to CMR. The aim was to evaluate late enhancement (LE) fibrosis mapping by CT, and to correlate the results with low-voltage areas on electroanatomical mapping (EAM). Methods: In patients with atrial fibrillation who underwent 128-slice dual-source CT angiography (CTA) prior to LA catheter ablation, an additional LE-CT scan was performed 7 min after CTA. (1) Left atrial wall thickness (LAWT) was measured at three sites along the LA ridge. (2) Late enhancement (LE) was quantified co-axially aligned to LAWT and compared with low-voltage areas (LVA) on EAM. Results: Of 137 patients (age: 59.8 years; 27.7% females), 108 were included. The prevalence of LE was higher in patients with LAWT > 2 mm compared with 1.5 mm, with 78 (91.7%) vs. 77 (80.2%) (p = 0.022). Of 78 patients with LE, 60 (77.1%) had focal, 13 (16.5%) had diffuse, and 5 (6.3%) had mixed LE patterns. The CT density of focal LE was not different from that of diffuse patterns (104.2 +/- 21 HU vs. 98.9 +/- 18 HU; p = 0.360). Increasing LAWT and LE-HU were weakly correlated (r = 0.229; p = 0.041). LA wall artifacts had higher CT density compared with LE (154.1 HU vs. 114.2 HU; p = 0.002). The effective radiation dose was 0.95 mSv (range, 0.52-1.2 mSv) for LE-CT. The agreement of LE-CT was 80% for LVA < 0.5 mV and 86.6% for LVA < 0.7 mV in a subset of 30 patients. Conclusions: Left atrial fibrosis mapping by LE-CT is feasible. Late enhancement was found more frequently in LAWTs of more than 2 mm, and LE was correlated with increasing LA remodeling and low-voltage areas.