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Introduction: Preliminary data suggest that high power short duration (HPSD) ablation for pulmonary vein isolation (PVI) are safe. Limited data are available on its effectiveness. Aim was to evaluate HPSD ablation in atrial fibrillation ablation using a novel Qdot Micro catheter., Methods and Results: Prospective multicenter study evaluating safety and efficacy of PVI with HPSD ablation. First pass isolation (FPI) and sustained PVI was assessed. If FPI was not achieved additional ablation index (AI)-guided ablation with 45 W was performed and metrics predictive of this were determined. Sixty-five patients and 260 veins were treated. Procedural and LA dwell time was 93.9 ± 30.4 and 60.5 ± 23.1 min, respectively. FPI was achieved in 47 (72.3%) patients and 231 veins (88.8%) with an ablation duration of 4.6 ± 1.0 min. Twenty-nine veins required additional AI-guided ablation to achieve initial PVI with 24 anatomical sites ablated with the right posterior carina being the most common site (37.5%). A contact force of ≥8 g (area under the curve [AUC]: 0.81; p < 0.001) and catheter position variation of ≤1.2 mm (AUC: 0.79; p < 0.001) with HPSD were strongly predictive of not requiring additional AI-guided ablation. Out of the 260 veins, only 5 (1.9%) veins showed acute reconnection. HPSD ablation was associated with shorter procedure times (93.9 vs. 159.4 min; p < 0.001), ablation times (6.1 vs. 27.7 min; p < 0.001), and lower rates of PV reconnection (9.2% vs. 30.8%; p = 0.004) compared to moderate power cohort., Conclusions: HPSD ablation is an effective ablation modality which results in effective PVI whilst maintaining a safety profile. Its superiority needs to be evaluated in randomized controlled trials., (© 2023 Wiley Periodicals LLC.)

Background: Mechanisms sustaining persistent atrial fibrillation (AF) remain uncertain., Objectives: The purpose of this study was to use electrocardiographic imaging (ECGI) mapping to guide localized driver ablation in patients with persistent AF., Methods: Patients undergoing catheter ablation for persistent AF <2 years were included. Patients were enrolled consecutively between 2018 and 2020. ECGI mapping was used to identify focal and rotational potential drivers (PDs). PDs were ablated after pulmonary vein isolation (PVI). The ablation response and freedom from AF/atrial tachycardia (AT) at 1 year were assessed., Results: Forty patients were enrolled. AF terminated with PVI in 8 patients, and 32 underwent ECGI-guided driver ablation. Average procedural duration was 228.8 ± 66.7 minutes, with a total radiofrequency delivery time of 38.9 ± 14.1 minutes. During 1 year of follow-up, the primary endpoint of freedom from AF/AT was achieved in 26 patients (65%). The secondary endpoint of freedom from AF was achieved in 30 patients (75%). AF termination was achieved in 20 of 40 patients (50%). The composite endpoint of an ablation response (AF termination or cycle length slowing ≥10%) occurred in 37 of 40 patients (92.5%). In total, 181 drivers (48 focal and 133 rotational) were ablated, with an ablation response achieved in 59 (32.6%). Focal drivers and drivers with a higher recurrence rate and greater temporal stability were more likely to be associated with an ablation response including AF termination (P <.001)., Conclusion: ECGI-guided ablation plus PVI results in high freedom from AF during follow-up and an ablation response in a large proportion of patients. Using driver type and characteristics may facilitate a hierarchical ablation approach., (Copyright © 2022 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The ganglionated plexuses (GPs) of the intrinsic cardiac autonomic system may play a role in atrial fibrillation (AF)., Objective: We hypothesized that ablating the ectopy-triggering GPs (ET-GPs) prevents AF., Methods: GANGLIA-AF (ClinicalTrials.gov identifier NCT02487654) was a prospective, randomized, controlled, 3-center trial. ET-GPs were mapped using high frequency stimulation, delivered within the atrial refractory period and ablated until nonfunctional. If triggered AF became incessant, atrioventricular dissociating GPs were ablated. We compared GP ablation (GPA) without pulmonary vein isolation (PVI) against PVI in patients with paroxysmal AF. Follow-up was for 12 months including 3-monthly 48-hour Holter monitors. The primary end point was documented ≥30 seconds of atrial arrhythmia after a 3-month blanking period., Results: A total of 102 randomized patients were analyzed on a per-protocol basis after GPA (n = 52; 51%) or PVI (n = 50; 49%). Patients who underwent GPA had 89 ± 26 high frequency stimulation sites tested, identifying a median of 18.5% (interquartile range 16%-21%) of GPs. The radiofrequency ablation time was 22.9 ± 9.8 minutes in GPA and 38 ± 14.4 minutes in PVI (P < .0001). The freedom from ≥30 seconds of atrial arrhythmia at 12-month follow-up was 50% (26 of 52) with GPA vs 64% (32 of 50) with PVI (log-rank, P = .09). ET-GPA without atrioventricular dissociating GPA achieved 58% (22 of 38) freedom from the primary end point. There was a significantly higher reduction in antiarrhythmic drug usage postablation after GPA than after PVI (55.5% vs 36%; P = .05). Patients were referred for redo ablation procedures in 31% (16 of 52) after GPA and 24% (12 of 50) after PVI (P = .53)., Conclusion: GPA did not prevent atrial arrhythmias more than PVI. However, less radiofrequency ablation was delivered to achieve a higher reduction in antiarrhythmic drug usage with GPA than with PVI., (Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Anatomical studies demonstrate significant variation in cavotricuspid isthmus (CTI) architecture., Methods: Thirty-eight patients underwent CTI ablation at two tertiary centers. Operators delivered 682 lesions with a target ablation index (AI) of 600 Wgs. Ablation parameters were recorded every 10-20 ms. Post hoc, Visitags were trisected according to CTI position: inferior vena cava (IVC), middle (Mid), or ventricular (V) lesions., Results: There were no complications. 92.1% of patients (n = 35) remained in sinus rhythm after 14.6 ± 3.4 months. For the whole CTI, peak AI correlated with mean impedance drop (ID) (R 2  = 0.89, p < .0001). However, analysis by anatomical site demonstrated a non-linear relationship Mid CTI (R 2  = 0.15, p = .21). Accordingly, while mean AI was highest Mid CTI (IVC: 473.1 ± 122.1 Wgs, Mid: 539.6 ± 103.5 Wgs, V: 486.2 ± 111.8 Wgs, ANOVA p < .0001), mean ID was lower (IVC: 10.7 ± 7.5Ω, Mid: 9.0 ± 6.5Ω, V: 10.9 ± 7.3Ω, p = .011), and rate of ID was slower (IVC: 0.37 ± 0.05 Ω/s, Mid: 0.18 ± 0.08 Ω/s, V: 0.29 ± 0.06 Ω/s, p < .0001). Mean contact force was similar at all sites; however, temporal fluctuations in contact force (IVC: 19.3 ± 12.0 mg/s, Mid: 188.8 ± 92.1 mg/s, V: 102.8 ± 32.3 mg/s, p < .0001) and catheter angle (IVC: 0.42°/s, Mid: 3.4°/s, V: 0.28°/s, p < .0001) were greatest Mid CTI. Use of a long sheath attenuated these fluctuations and improved energy delivery., Conclusions: Ablation characteristics vary across the CTI. At the Mid CTI, higher AI values do not necessarily deliver more effective ablation; this may reflect localized fluctuations in catheter angle and contact force., (© 2021 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Catheter ablation is an established effective approach for the treatment of atrial fibrillation (AF) in patients with heart failure, however, the role of cryoablation in this setting is unclear. Procedural success and left ventricular systolic dysfunction (LVEF) improvement in patients with LVEF ≤ 45% undergoing index catheter ablation with cryoablation were evaluated. Freedom from AF recurrence was seen in 43% rising to 59% following repeat procedure. There were significant improvements in LVEF and functional status at long-term follow-up. Results were comparable to a contemporaneous cohort of heart failure patients undergoing index ablation with radiofrequency ablation. Cryoablation is an effective first-line AF ablation approach in the setting of heart failure., (© 2021 Wiley Periodicals LLC.)

Introduction: The optimal ablation approach for persistent atrial fibrillation (AF) remains unclear., Methods and Results: Objective was to compare the long-term rates of freedom from AF/AT in patients that underwent STAR mapping guided ablation against outcomes of patients undergoing conventional ablation procedures. Patients undergoing ablation for persistent AF as part of the Stochastic Trajectory Analysis of Ranked signals (STAR) mapping study were included. Outcomes following 'pulmonary vein isolation (PVI) plus STAR mapping guided ablation (STAR mapping cohort) were compared to patients undergoing PVI alone ablation during the same time period and also a propensity-matched cohort undergoing PVI plus the addition of complex fractionated electrogram (CFAE) and/or linear ablation ("conventional ablation"). Rates of procedural AF termination and freedom from AF/AT during follow-up were compared. Sixty-five patients were included in both the STAR cohort and propensity matched conventional ablation cohort. AF termination rates were significantly higher in the STAR cohort (51/65, 78.5%) than conventional ablation cohort (10/65, 15.4%) and PVI alone ablation cohort (13/50, 26.0%; STAR cohort vs. other 2 cohorts both p < .001). There was no significant difference in procedure time between the three cohorts. During ≥20 months follow-up a lower proportion of patients had AF/AT recurrence in the STAR cohort (20.0%) compared with the conventional ablation cohort (50.8%) or the PVI alone ablation cohort (50.0%; both p < .05 compared to STAR cohort)., Conclusions: Outcomes of PVI plus STAR mapping guided ablation was superior to PVI alone or in combination with linear/CFAE ablation. A multicenter randomized controlled trial is planned to confirm these findings., (© 2020 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.)

Introduction: The frequency of catheter ablation for atrial fibrillation (AF) has increased dramatically, stretching resources. Discharge on the same day as treatment may increase the efficiency and throughput. There are limited data regarding the safety of this strategy., Methods: We performed a retrospective analysis of consecutive patients undergoing AF ablation in a tertiary center and in a district general hospital, and identified those discharged on the same day of treatment. The safety endpoint was any complication and/or presentation to hospital in the 48-h and at 30 days postdischarge. We performed an economic analysis to calculate potential cost saving., Results: Among a total population of 2628 patients, we identified 727 subjects (61.1 ± 12.5 years, 69.6% male) undergoing day-case AF ablation. Cryoballoon technique was used in 79.2% of the day-cases, and 91.6% of the procedures were performed under conscious sedation. 1.8% (13) of the participants met the safety composite endpoint at 48-h, however only 0.7% (5) required at least 1 day of hospitalization. Bleeding or hematoma at the femoral access site (0.5%) and pericarditic chest pain (0.5%) were the main reasons for readmission. None experienced cardiac tamponade or other life-threatening complications in the 48-h postdischarge. Overall rate of complication and/or presentation to hospital at 30 days was 3.7%. Our day-case policy resulted in an annual cost-saving of approximately of £83 927 for our hospital., Conclusion: In this large multicentre cohort, same-day discharge in selected patients following AF ablation appears to be safe and cost-effective, with a very low rate of early readmission or post-discharge complication., (© 2020 Wiley Periodicals LLC.)

Aims: Despite recent advances in catheter ablation for atrial fibrillation (AF), pulmonary vein reconnection (PVR), and AF recurrence remain significantly high. Ablation index (AI) is a new method incorporating contact force, time, and power that should optimize procedural outcomes. We aimed to evaluate the efficacy and safety of AI-guided catheter ablation compared to a non-AI-guided approach., Methods and Results: A systematic search was performed on MEDLINE (via PubMED), EMBASE, COCHRANE, and European Society of Cardiology (ESC) databases (from inception to 1 July 2019). We included only studies that compared AI-guided with non-AI-guided catheter ablation of AF. Eleven studies reporting on 2306 patients were identified. Median follow-up period was 12 months. Ablation index-guided ablation had a significant shorter procedural time (141.0 vs. 152.8 min, P = 0.01; I2 = 90%), ablation time (21.8 vs. 32.0 min, P < 0.00001; I2 = 0%), achieved first-pass isolation more frequently [odds ratio (OR) = 0.09, 95%CI 0.04-0.21; 93.4% vs. 62.9%, P < 0.001; I2 = 58%] and was less frequently associated with acute PVR (OR = 0.37, 95%CI 0.18-0.75; 18.0% vs 35.0%; P = 0.006; I2 = 0%). Importantly, atrial arrhythmia relapse post-blanking was significantly lower in AI compared to non-AI catheter ablation (OR = 0.41, 95%CI 0.25-0.66; 11.8% vs. 24.9%, P = 0.0003; I2 = 35%). Finally, there was no difference in complication rate between AI and non-AI ablation, with the number of cardiac tamponade events in the AI group less being numerically lower (OR = 0.69, 95%CI 0.30-1.60, 1.6% vs. 2.5%, P = 0.39; I2 = 0%)., Conclusions: These data suggest that AI-guided catheter ablation is associated with increased efficacy of AF ablation, while preserving a comparable safety profile to non-AI catheter ablation., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Background: Maintenance of sinus rhythm is challenging in patients with longstanding persistent atrial fibrillation (PeAF). Minimally invasive surgical AF ablation may improve outcomes when combined with catheter ablation (the 'convergent' procedure). This study evaluates the safety and efficacy of the convergent procedure versus catheter ablation alone in longstanding PeAF., Methods: 43 consecutive patients with longstanding PeAF underwent subxiphoid endoscopic ablation of the posterior left atrium followed by catheter ablation from 2013 to 2018. The primary outcome was AF-free survival at 12 months; secondary outcomes included change in EHRA class, echocardiographic data, procedural complications, freedom from anti-arrhythmic drugs (AADs), and long term arrhythmia-free survival. Outcomes were compared with a matched group of 43 patients who underwent catheter ablation alone. Both groups underwent multiple catheter ablations as required. Baseline characteristics were similar between groups., Results: After 12 months, the convergent procedure was associated with increased AF-free survival on AADs (60.5% versus 25.6%, p = .002) and off AADs (37.2% versus 13.9%, p = .025), versus catheter ablation. Allowing for multiple procedures, after 30.5 ± 13.3 months' follow-up the convergent procedure was associated with increased arrhythmia-free survival on AADs (58.1% versus 30.2%, p = .016) and off AADs (32.5% versus 11.6%, p = .036) versus catheter ablation. There were more complications in the convergent procedure group (11.6% versus 2.3%, p = .2). Multivariate analysis identified only the convergent procedure (OR 3.06 (1.23-7.6), p = .017) as predictive of arrhythmia-free survival long term., Conclusions: In longstanding PeAF, the convergent procedure is associated with improved arrhythmia-free survival versus catheter ablation alone. Complication rates are significant but have been shown to depreciate with experience., Competing Interests: Declaration of competing interest Dr. Ahsan has received an educational grant and speaker fees from Atricure., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Aims: Although cryoballoon pulmonary vein isolation is a well-established treatment for paroxysmal atrial fibrillation (AF), it's role in persistent AF is unclear. We examined procedural success and long-term outcomes of cryoablation in persistent and longstanding persistent AF., Methods and Results: International multicentre registry from three UK and eight European centres. Consecutive patients undergoing cryoablation for persistent AF included. Procedural data, complications, and follow-up were prospectively recorded. Patients were followed-up at 3, 6, and 12 months with an electrocardiogram with open access to arrhythmia nurses thereafter. Ambulatory monitoring was dictated by symptoms. Success was defined as freedom from AF or atrial tachycardia lasting >30 s off antiarrhythmic drugs (AADs). Six hundred and nine consecutive cryoablation procedures. Mean procedure and fluoroscopy times were 95 ± 65 and 13 ± 10 min. Single procedure success rates were 368/602 (61%) off AADs over a median of 2.4 (1.0-4.0) years. Arrhythmia-free survival off AADs was 64% and 57% for persistent and longstanding persistent AF at 24 months of follow-up (P = 0.02). Rate of repeat ablations was 20% in persistent and 32% in longstanding persistent AF (P = 0.006). Cox regression analyses showed a significant association between duration of AF and left atrial diameter and arrhythmia recurrence [hazard ratio (HR) 1.05, P-value 0.01 and HR 1.02, P-value 0.004]., Conclusion: Cryoablation for persistent AF is safe, fast and has good outcomes at long-term follow-up. Cryoablation is reasonable as a first line option for these patients. Short procedure times may help increase capacity of cardiac units to meet the rising demand for AF ablation. Randomised control trials are needed to compare outcomes with different techniques., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Background: ECG imaging (ECGI) has been used to guide treatment of ventricular ectopy and arrhythmias. However, the accuracy of ECGI in localizing the origin of arrhythmias during catheter ablation of ventricular tachycardia (VT) in structurally abnormal hearts remains to be fully validated., Methods: During catheter ablation of VT, simultaneous mapping was performed using electroanatomical mapping (CARTO, Biosense-Webster) and ECGI (CardioInsight, Medtronic) in 18 patients. Sites of entrainment, pace-mapping, and termination during ablation were used to define the VT site of origin (SoO). Distance between SoO and the site of earliest activation on ECGI were measured using co-registered geometries from both systems. The accuracy of ECGI versus a 12-lead surface ECG algorithm was compared., Results: A total of 29 VTs were available for comparison. Distance between SoO and sites of earliest activation in ECGI was 22.6, 13.9 to 36.2 mm (median, first to third quartile). ECGI mapped VT sites of origin onto the correct AHA segment with higher accuracy than a validated 12-lead ECG algorithm (83.3% versus 38.9%; P =0.015)., Conclusions: This simultaneous assessment demonstrates that CardioInsight localizes VT circuits with sufficient accuracy to provide a region of interest for targeting mapping for ablation. Resolution is not sufficient to guide discrete radiofrequency lesion delivery via catheter ablation without concomitant use of an electroanatomical mapping system but may be sufficient for segmental ablation with radiotherapy.

Background: Pulmonary vein isolation (PVI) using high power delivered by SmartTouch Surround Flow (STSF) catheters guided by ablation index (AI) was evaluated in a multicenter registry., Methods: Patients with paroxysmal AF underwent PVI with STSF catheters using 30 W on the posterior wall and 40 W elsewhere. AI targets were 350 posterior walls and 450 elsewhere. Procedures were compared with controls using conventionally irrigated contact force-sensing catheters using conventional powers (25 W posterior wall and 30 W elsewhere) guided by force-time integral (no agreed targets). The waiting period of 30 minutes was observed before adenosine administration to assess acute pulmonary vein (PV) reconnection., Results: One hundred patients from four centers were included: 50 patients in the high power ablation index (HPAI) group and 50 controls. Procedure time was 22% shorter in the HPAI group (156 [133.8-179] vs 199 [178.5-227] minutes; P < 0.001). Duration of the radiofrequency application was 37% shorter in the HPAI group (27.2 [21.5-35.8] vs 43.2 [35.1-52.1] minutes; P < 0.001). Acute PV reconnection was reduced (28 of 200 [14%] vs 48 of 200 [24%] veins; P = 0.015). Reconnection was predicted by a largest interlesion distance greater than 6 mm, a lesion with impedance drop less than 2.5 Ω, contact force less than 6 g, or less than 68% of the regional AI target (all P < 0.001). Freedom from atrial arrhythmia at 1 year off antiarrhythmic drugs after a single procedure was 78% in the HPAI group vs 64% in the control group ( P = 0.186)., Conclusion: High-powered ablation guided by AI was safe and led to shorter procedure times with reduced acute PV reconnection compared with conventional ablation., (© 2018 Wiley Periodicals, Inc.)

Introduction: Catheter ablation has been evaluated as treatment for fascicular ventricular tachycardia (FVT) in several single-centre cohort studies, with variable results regarding efficacy and outcomes., Methods: A systematic search was performed on PubMed, EMBASE and Cochrane database (from inception to November 2017) that included studies on FVT catheter ablation., Results: Thirty-eight observational non-controlled case series comprising 953 patients with FVT undergoing catheter ablation were identified. Three studies were prospective and only 5 were multi-centre. Eight-hundred and eighty-four patients (94.2%) had left posterior FVT, 25 (3.4%) left anterior FVT and 30 (2.4%) other forms. In 331 patients (41%), ablation was performed in sinus rhythm (SR). The mean follow-up period was 41.4 ± 10.7 months. Relapse of FVT occurred in 100 patients (10.7%). Among the 79 patients (8.3%) requiring a further procedure after the index ablation, 19 (2%) had further FVT relapses. Studies in which ablation was performed in FVT had similar success rate after multiple procedures compared to ablation in SR only (95.1%, CI 95% 92.2-97%, I 2  = 0% versus 94.8%, CI 95% 87.6-97.9%, I 2  = 0%, respectively). Success rate was numerically lower in paediatric-only series compared to non-paediatric cases (90.0%, CI 95% 82.1-94.6%, I 2  = 0% versus 94.3%, CI 95% 92.2-95.9%, I 2  = 0%, respectively)., Conclusion: Data derived from observational non-controlled case series, with low-methodological quality, suggest that catheter ablation is a safe and effective treatment for FVT, with a 93.5% success rate after multiple procedures. Ablation during FVT represents the first-line and most commonly used approach; however, a strategy of mapping and ablation during SR displayed comparable procedural results to actively mapping patients in FVT and should therefore be considered in selected cases where FVT is not inducible., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Introduction: Panoramic mapping with basket catheters has been used to map atrial fibrillation (AF). However, the limited tissue contact and coverage achieved has raised concerns., Methods and Results: Patients undergoing catheter ablation for atrial tachycardia (AT) and persistent AF were recruited. Unipolar signals were recorded with the Constellation or FIRMap catheters. The proportion and distribution of anatomical coverage by the catheters was determined and tissue contact achieved measured. The impact of catheter position, left atrium (LA) size, and bipolar voltage were evaluated. Forty patients were recruited (20 Constellation and 20 FIRMap). The LA coverage achieved with the FIRMap catheter compared to the Constellation catheter was greater (76.9 ± 12.9% vs. 50.8 ± 10.3%; P < 0.001), with better septal coverage (66.8 ± 20.9% vs. 15.5 ± 12.0%; P < 0.001). A greater number of electrodes recorded peak-to-peak electrogram amplitude of ≥0.5 mV (84.2% vs. 62.8%; P < 0.001). Positioning the catheter tip at or posterior to LA appendage ridge gave better coverage than a more anterior position (P = 0.001). Increasing LA area correlated inversely with coverage (P < 0.001) and contact (P = 0.002) despite patient-specific basket catheter sizing. An LA area of >30 cm 2 and mean bipolar voltage of <0.3 mV was associated with reduction in coverage and contact (both P < 0.001). There was a significant difference in AT/AF freedom during follow-up in the FIRMap versus Constellation group (13/13 vs. 8/12; P = 0.04)., Conclusions: The FIRMap is superior to the Constellation catheter in terms of LA coverage and contact. Optimizing catheter position and appropriate patient selection based on no more than moderately dilated or scarred atria will also facilitate mapping with basket catheters., (© 2017 Wiley Periodicals, Inc.)