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Aims Catheter ablation (CA) of post-ablation left atrial tachycardias (LATs) can be challenging. So far, pulsed field ablation (PFA) has not been compared to standard point-by-point radiofrequency current (RFC) energy for LAT ablation. To compare efficacy of PFA vs. RFC in patients undergoing CA for LAT. Methods and results Consecutive patients undergoing LAT-CA were prospectively enrolled (09/2021–02/2023). After electro-anatomical high-density mapping, ablation with either a pentaspline PFA catheter or RFC was performed. Patients were matched 1:1. Ablation was performed at the assumed critical isthmus site with additional ablation, if necessary. Right atrial tachycardia (RAT) was ablated with RFC. Acute and chronic success were assessed. Fifty-six patients (n = 28 each group, age 70 ± 9 years, 75% male) were enrolled. A total of 77 AT (n = 67 LAT, n = 10 RAT; 77% macroreentries) occurred with n = 32 LAT in the PFA group and n = 35 LAT in the RFC group. Of all LAT, 94% (PFA group) vs. 91% (RFC group) successfully terminated to sinus rhythm or another AT during ablation (P = 1.0). Procedure times were shorter (PFA: 121 ± 41 vs. RFC: 190 ± 44 min, P < 0.0001) and fluoroscopy times longer in the PFA group (PFA: 15 ± 9 vs. RFC: 11 ± 6 min, P = 0.04). There were no major complications. After one-year follow-up, estimated arrhythmia free survival was 63% (PFA group) and 87% (RFC group), [hazard ratio 2.91 (95% CI: 1.11–7.65), P = 0.0473]. Conclusion Pulsed field ablation of post-ablation LAT using a pentaspline catheter is feasible, safe, and faster but less effective compared to standard RFC ablation after one year of follow-up. Future catheter designs and optimization of the electrical field may further improve practicability and efficacy of PFA for LAT. [ABSTRACT FROM AUTHOR]

Introduction: Pulsed field ablation (PFA) represents a novel, nonthermal energy modality that can be applied for single‐shot pulmonary vein isolation (PVI) in atrial fibrillation (AF). Comparative data with regard to deep sedation to established single‐shot modalities such as cryoballoon (CB) ablation are scarce. The aim of this study was to compare a deep sedation protocol in patients receiving PVI with either PFA or CB. Methods: Prospective, consecutive AF patients undergoing PVI with a pentaspline PFA catheter were compared to a retrospective CB‐PVI cohort of the same timeframe. Study endpoints were the requirements of analgesics, cardiorespiratory stability, and sedation‐associated complications. Results: A total of 100 PVI patients were included (PFA n = 50, CB n = 50, mean age 66 ± 10.6, 61% male patients, 65% paroxysmal AF). Requirement of propofol, midazolam, and sufentanyl was significantly higher in the PFA group compared to CB [propofol 0.14 ± 0.04 mg/kg/min in PFA vs. 0.11 ± 0.04 mg/kg/min in CB (p =.001); midazolam 0.00086 ± 0.0004 mg/kg/min in PFA vs. 0.0006295 ± 0.0003 mg/kg/min in CB (p =.002) and sufentanyl 0.0013 ± 0.0007 µg/kg/min in PFA vs. 0.0008 ± 0.0004 µg/kg/min in CB (p <.0001)]. Sedation‐associated complications did not differ between both groups (PFA n = 1/50 mild aspiration pneumonia, CB n = 0/50, p >.99). Nonsedation‐associated complications (PFA: n = 2/50, 4%, CB: n = 1/50, 2%, p >.99) and procedure times (PFA 75 ± 31, CB 84 ± 32 min, p =.18) did not differ between groups. Conclusions: PFA is associated with higher sedation and especially analgesia requirements. However, the safety of deep sedation does not differ to CB ablation. This study sought to compare the requirements and safety of deep sedation in patients undergoing pulmonary vein isolation (PVI) with either a pentaspline pulsed field ablation (PFA) catheter, a novel energy modality, or cryoballoon (CB) ablation, an established energy source. In 100 patients undergoing PVI (PFA: n = 50, CB: n = 50), the requirement of analgosedation was significantly higher in the PFA group compared to CB, especially with regard to analgesics. There was no difference in sedation‐associated and nonsedation‐associated complications between groups. [ABSTRACT FROM AUTHOR]

Aims: Catheter contact and local tissue characteristics are relevant information for successful radiofrequency current (RFC)‐ablation. Local impedance (LI) has been shown to reflect tissue characteristics and lesion formation during RFC‐ablation. Using a novel ablation catheter incorporating three mini‐electrodes, we investigated LI in relation to generator impedance (GI) in patients with ventricular tachycardia (VT) and its applicability as an indicator of effective RFC‐ablation. Methods and Results: Baseline impedance, Δimpedance during ablation and drop rate (Δimpedance/time) were analyzed for 625 RFC‐applications in 28 patients with recurrent VT undergoing RFC‐ablation. LI was lower in scarred (87.0 Ω [79.0‐95.0]) compared to healthy myocardium (97.5 Ω ([82.75‐111.50]; P =.03) while GI did not differ between scarred and healthy myocardium. ΔLI was higher (18 Ω [9.4‐26.0]) for VT‐terminating as compared to non‐terminating RFC‐ablation (ΔLI 13 Ω [8.85‐18.0]; P =.03), but did not differ for ΔGI between terminating vs nonterminating RFC‐ablation. Correspondingly, LI drop rate was higher for RFC‐ablation terminating the VT compared with RFC‐ablation not terminating the VT (0.63 Ω/s [0.52‐0.76] vs 0.32 Ω [0.20‐0.58]; P =.008) while there was no difference for GI drop rate. ΔLI was higher in patients with nonischemic cardiomyopathy vs patients with ischemic cardiomyopathy (16 Ω [11.0‐20.0] vs 11.0 Ω [7.85‐17.00]; P =.003). Conclusion: Our findings suggest that LI is a sensitive parameter to guide RFC‐ablation in patients with VT. LI indicates differences in tissue characteristics and generally is higher in patients with nonischemic cardiomyopathy. Hence, the etiology of the underlying cardiomyopathy needs to be considered when adopting LI for monitoring catheter ablation of VT. [ABSTRACT FROM AUTHOR]

Aims: Catheter ablation (CA) of post-ablation left atrial tachycardias (LATs) can be challenging. So far, pulsed field ablation (PFA) has not been compared to standard point-by-point radiofrequency current (RFC) energy for LAT ablation. To compare efficacy of PFA vs. RFC in patients undergoing CA for LAT., Methods and Results: Consecutive patients undergoing LAT-CA were prospectively enrolled (09/2021-02/2023). After electro-anatomical high-density mapping, ablation with either a pentaspline PFA catheter or RFC was performed. Patients were matched 1:1. Ablation was performed at the assumed critical isthmus site with additional ablation, if necessary. Right atrial tachycardia (RAT) was ablated with RFC. Acute and chronic success were assessed. Fifty-six patients (n = 28 each group, age 70 ± 9 years, 75% male) were enrolled.A total of 77 AT (n = 67 LAT, n = 10 RAT; 77% macroreentries) occurred with n = 32 LAT in the PFA group and n = 35 LAT in the RFC group. Of all LAT, 94% (PFA group) vs. 91% (RFC group) successfully terminated to sinus rhythm or another AT during ablation (P = 1.0). Procedure times were shorter (PFA: 121 ± 41 vs. RFC: 190 ± 44 min, P < 0.0001) and fluoroscopy times longer in the PFA group (PFA: 15 ± 9 vs. RFC: 11 ± 6 min, P = 0.04). There were no major complications. After one-year follow-up, estimated arrhythmia free survival was 63% (PFA group) and 87% (RFC group), [hazard ratio 2.91 (95% CI: 1.11-7.65), P = 0.0473]., Conclusion: Pulsed field ablation of post-ablation LAT using a pentaspline catheter is feasible, safe, and faster but less effective compared to standard RFC ablation after one year of follow-up. Future catheter designs and optimization of the electrical field may further improve practicability and efficacy of PFA for LAT., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Introduction: Respiratory sinus arrhythmia (RSA) describes heart rate (HR) changes in synchrony with respiration. It is relevant for exercise capacity and mechanistically linked with the cardiac autonomic nervous system. After pulmonary vein isolation (PVI), the current therapy of choice for patients with paroxysmal atrial fibrillation (AF), the cardiac vagal tone is often diminished. We hypothesized that RSA is modulated by PVI in patients with paroxysmal AF., Material and Methods: Respiratory sinus arrhythmia, measured by using a deep breathing test and heart rate variability parameters, was studied in 10 patients (64 ±3 years) with paroxysmal AF presenting in stable sinus rhythm for their first catheter-based PVI. Additionally, heart rate dynamics before and after PVI were studied during sympathetic/parasympathetic coactivation by using a cold-face test. All tests were performed within 24 h before and 48 h after PVI., Results: After PVI RSA (E/I difference: 7.9 ±1.0 vs. 3.5 ±0.6 bpm, p = 0.006; E/I ratio: 1.14 ±0.02 vs. 1.05 ±0.01, p = 0.003), heart rate variability (SDNN: 31 ±3 vs. 14 ±3 ms, p = 0.006; RMSSD: 17 ±2 vs. 8 ±2 ms, p = 0.002) and the HR response to sympathetic/parasympathetic coactivation (10.2 ±0.7% vs. 5.7 ±1.1%, p = 0.014) were diminished. The PVI-related changes in RSA correlated with the heart rate change during sympathetic/parasympathetic coactivation before vs. after PVI (E/I difference: r = 0.849, p = 0.002; E/I ratio: r = 0.786, p = 0.007). One patient with vagal driven arrhythmia experienced AF recurrence during follow-up (mean: 6.5 ±0.6 months)., Conclusions: Respiratory sinus arrhythmia is reduced after PVI in patients with paroxysmal AF. Our findings suggest that this is related to a decrease in cardiac vagal tone. Whether and how this affects the clinical outcome including exercise capacity need to be determined., Competing Interests: The authors declare no conflict of interest., (Copyright: © 2019 Termedia & Banach.)

Aims: A novel measure of local impedance (LI) has been found to predict lesion formation during radiofrequency current (RFC) catheter ablation. The aim of this study was to investigate the utility of this novel approach, while comparing LI to the well-established generator impedance (GI)., Methods and Results: In 25 consecutive patients with a history of atrial fibrillation, catheter ablation was guided by a 3D-mapping system measuring LI in addition to GI via an ablation catheter tip with three incorporated mini-electrodes. Local impedance and GI before and during RFC applications were studied. In total, 381 RFC applications were analysed. The baseline LI was higher in high-voltage areas (>0.5 mV; LI: 110.5 ± 13.7 Ω) when compared with intermediate-voltage sites (0.1-0.5 mV; 90.9 ± 10.1 Ω, P < 0.001), low-voltage areas (<0.1 mV; 91.9 ± 16.4 Ω, P < 0.001), and blood pool LI (91.9 ± 9.9 Ω, P < 0.001). During ablation, mean LI drop (△LI; 13.1 ± 9.1 Ω) was 2.15 times higher as mean GI drop (△GI) (6.1 ± 4.2 Ω, P < 0.001). Baseline LI correlated with △LI: a mean LI of 99.9 Ω predicted a △LI of 12.9 Ω [95% confidence interval (12.1-13.6), R2 0.41; P < 0.001]. This relationship was weak for baseline GI predicting △GI (R2 0.06, P < 0.001). Catheter movements were represented by rapid LI changes. The duration of an RFC application was not predictive for catheter-tissue coupling with no further change of △LI (P = 0.247) nor △GI (P = 0.376) during prolonged ablation., Conclusion: Local impedance can be monitored during ablation. Compared with the sole use of GI, baseline LI is a better predictor of impedance drops during ablation and may provide useful insights regarding lesion formation. However, further studies are needed to investigate if this novel approach is useful to guide catheter ablation., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Aims: During ablation in the vicinity of the coronary arteries establishing a safe distance from the catheter tip to the relevant vessels is mandatory and usually assessed by fluoroscopy alone. The aim of the study was to investigate the feasibility of an image integration module (IIM) for continuous monitoring of the distance of the ablation catheter tip to the main coronary arteries during ablation of ventricular arrhythmias (VA) originating in the sinus of valsalva (SOV) and the left ventricular summit part of which can be reached via the great cardiac vein (GCV)., Methods and Results: Of 129 patients undergoing mapping for outflow tract arrhythmias from June 2014 till October 2015, a total of 39 patients (52.4 ± 18.1 years, 17 female) had a source of origin in the SOV or the left ventricular summit. Radiofrequency (RF) ablation was performed when a distance of at least 5 mm could be demonstrated with IIM. A safe distance in at least one angiographic plane could be demonstrated in all patients with a source of origin in the SOV, whereas this was not possible in 50% of patients with earliest activation in the summit area. However, using the IIM a safe position at an adjacent site within the GCV could be obtained in three of these cases and successful RF ablation performed safely without any complications. Ablation was successful in 100% of patients with an origin in the SOV, whereas VAs originating from the left ventricular summit could be abolished completely in only 60% of cases., Conclusion: Image integration combining electroanatomical mapping and fluoroscopy allows assessment of the safety of a potential ablation site by continuous real-time monitoring of the spatial relations of the catheter tip to the coronary vessels prior to RF application. It aids ablation in anatomically complex regions like the SOV or the ventricular summit providing biplane angiograms merged into the three-dimensional electroanatomical map., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.)

Introduction: Comparative data of early recurrence rates of atrial fibrillation (ERAF) following second-generation cryoballoon (CB-G2) and radiofrequency current (RFC) ablation for pulmonary vein isolation (PVI) in paroxysmal AF (PAF) are rare. We randomized PAF patients into either PVI with CB-G2 (group 1) or PVI with a combined RFC-approach applying contact force (CF) with the endpoint of unexcitability (group 2) to investigate ERAF., Methods and Results: In group 1 (n = 30), CB-G2-PVI was performed. After CF-PVI in group 2 (n = 30), bipolar pacing on the ablation line and additional ablation until unexcitability was conducted. Follow-up included 48 h of in-hospital monitoring followed by 5-day Holter ECGs 1, 2, 3, 6, 12 months postablation to evaluate ERAF. Acute PVI was reached in 100% of group 2 and in 99% of group 1. Shorter procedure durations (98.0 ± 21.9 vs. 114.3 ± 18.7 min, P < 0.05) but extended fluoroscopy times (15.4 ± 3.9 vs. 10.0 ± 4.3 min, P < 0.05) were found in the CB-G2 group. Ten non-severe complications occurred (6 vs. 4 in group 1 and 2, P = 0.73). In group 2, five patients suffered from ERAF vs. seven patients in group 1 (P = 0.67). The time until the occurrence of ERAF was shorter in group 2 (1 day (q1-q3: 1-4.5)) when compared with group 1 (22 (q1-q3: 6-54) days, P = 0.025)., Conclusion: ERAF rates were equal among groups; however, they occurred earlier in the initial phase after RFC ablation when compared with CB-G2. PVI utilizing cryoablation is associated with shorter procedure durations but extended fluoroscopy time while being similarly secure., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)