Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
In patients with longstanding persistent atrial fibrillation (LSPAF), mapping with multipolar catheter can enhance ...identification of arrhythmogenic sources during ongoing AF/converted atrial tachycardia (AT), reduce procedure time, and improve outcome of catheter ablation.
Purpose
To compare procedural characteristics and long-term outcome of radiofrequency catheter ablation (RFA) for LSPAF between two mapping approaches in a prospective randomized bi-centric study.
Methods
Between 1/2019-9/2021, RFA was performed in in 172 patients with LSPAF. Mapping with multipolar catheter Pentaray (group 1, n=85) vs. mapping with ablation catheter Navistar STSF (group 2, n=87) were compared. Stepwise ablation to the desired AF termination included pulmonary vein isolation (PVI), electrogram guided left atrial (LA) ablation, CS isolation, and right atrial electrogram guided ablation. PVI, mitral isthmus, LA roof, and CTI block were Intermediate endpoints proved at the procedure end. Sinus rhythm (SR) restoration by ablation was the desired procedure endpoint. Follow-up included 7-day ECG monitoring every 3 months during the first year, and every 6 months afterwards.
Results
In groups 1 vs. 2, AF was terminated (into SR or AT) in 70 (82%) vs. 68 (78%) patients (p=0.81); and SR was restored by ablation in 54 (64%) vs. 46 (53%) patients(p=0.46), respectively. Procedure, fluoroscopy, and RF delivery times (min) were 251±46 vs. 257±45 (p=0.35); 10,4±2,8 vs. 11,0±3,1 (p=0.17), and 70±21 vs. 70±24 (p=0.98), respectively. At the end of 13-45 months follow-up, stable SR was present in 72 (85%) vs. 69 (79%), patients following repeat ablation in 42 (49%) vs. 42 (48%) patients. Only 29 (34%) vs. 26 (30%) patients remained free from any AF/AT recurrence (>30 s) after single ablation (all p=NS).
Conclusion
Mapping with multipolar catheter vs. standard ablation catheter was associated with nonsignificant differences in procedural characteristics and clinical results of RF catheter ablation for LSPAF.
Abstract Background There is a limited knowledge on atrial arrhythmias recurring after complex left atrial (LA) pulsed field ablation (PFA) for longstanding persistent atrial fibrillation (LSPAF). ...Purpose To present recurrent atrial arrhythmias and their sources found at repeat ablation following PFA for LSPAF. Methods and results Of 214 patients with LSPAF (age 65±8, 53 females, continuous AF for 30±27 months) with complex LA PFA (Farapulse) in 10/2021-10/2023, 19 patients (64±8 years, 5 females) underwent repeat ablation for recurrent AF or arial tachycardia (AT) in 20 procedures. First PFA procedure included pulmonary vein isolation (PVI), roof/posterior wall, and mitral isthmus/coronary sinus/Ligament of Marshal region (LOM) ablation. At repeat ablation, 3D activation and entrainment mapping and ablation identified the AF/AT sources; ATs sources were classified as macroreentry (MRAT) (perimitral, roof-dependent, typical flutter) or localized (LOCAT) in case of smaller reentry or ectopic origin. Results The clinical recurrent arrhythmias included paroxysmal AF (n=1), persistent AF (n=2), paroxysmal AT (n=1) or persistent AT (n=16). At the onset of repeat ablation, persistent AF/AT was present (n=15) or had to be induced (n=5). AF was finally present during the procedure in 8 patients, and was terminated by ablation directly into SR (n=3) or into intermediate AT (n=3) (conversion sites included LA ridge/LOM region 2x, RA septum 1x, RA low lateral 2x, CTI 1x), or required DCC (n=2). Primary recurrent or from AF converted AT was present in 15 patients; only MRAT in 6 patients, only LOCAT in 3 patients, and both AT types in 6 (patients). Of MRAT (N. ATs = 16), there were 12 perimitral ATs, 0 roof-dependent AT, and 2 typical flutters. Of LOCATs, sources were located at LA anterior wall 4x, LA septum 2x, LA roof 1x, LA ridge/LOM 1x, persistent left vena cava 1x, and RA – para SA node 1x. Recurrent AF/AT sources were targeted by radiofrequency or PFA in 16 and 4 cases, respectively, all spontaneous and induced AF/AT were finally terminated into SR in 16 cases, subsequent noninducibility by atrial pacing up to 300 bpn was achieved in 13 cases, and recurrent AF/AT occurred in 3 patients. Conclusion At repeat ablation PFA (Farapulse) for LSPAF, recurrent AT dominated over AF, MRAT slightly prevailed over LOCAT, mostly constituted by perimitral AT, while roof-dependent AT recurrence was reduced to zero. A majority of AF/AT sources were located outside prior PFA lesions at the LA anterior wall, septum and the right atrium.
Abstract Background There is a limited knowledge on immediate and long-term efficacy of pulsed field ablation (PFA) for residual atrial tachycardia (AT) recurring after persistent atrial fibrillation ...ablation (AF). Purpose To present immediate and medium-term outcome of PFA (Farapulse) for complex AT recurring after ≥1 radiofrequency ablation (RFA) of primary (longstanding) persistent AF. Methods In 5/2022-10/2023, 81 patients (64±8 years, 19 females) underwent PFA for complex AT in 83 PFA procedures after prior RFA procedure(s); in first (n=21), second (n=33), third (n=23), fourth (n=5), or fifth (n=1) repeat ablation procedure, respectively. Mapping/ablation strategy was directed by the CS activation/entrainment to: 1) no 3D mapping and direct PFA in left atrium (n=67); 2) PFA directly after 3D LA mapping (n=9); 3) PFA following RFA after 3D LA mapping (n=7). AT sources were classified as macroreentry (MRAT) (perimitral, roof-dependent, typical flutter) or localized (LOCAT) in case of smaller reentry or ectopic origin. Results At the procedure onset, persistent AT was present in 58 patients, in the remaining cases AT (n=21) or AF (n=4) were induced. AF eventually occurred at some time of procedure in another 10 patients and was terminated by ablation at LA ridge/CS/LOM region 8x, LA posterior wall 3x, LUPV 1x, RUPV 1x, and RA low lateral wall 1x. Only MRAT, only LOCAT, or both AT types were found at 34 (41%), 35 (42%), and 14 (17%) procedures, respectively. A total of 125 ATs was identified (1, 2, and 3 ATs in 52, 20, and 11 patients). MRAT (n=60) included 32 perimitral ATs, 20 roof-dependent ATs, and 8 typical flutters. LOCAT (n=65) included RUPV source (n=1), LA extraPV sources (n=59), and RA sources (n=5). SR was restored with a 5±7 PFA applications at the site of AF source, total of PFA deliveries was 71±27, and procedure and fluoroscopy times were and 89±37 and 9±5 minutes, respectively. In the 7 patients with initial ineffective 6, 6, 11, 5, 18, 10, and 2 minutes of RFA, the AT was converted into SR by subsequent 1, 4, 1, 13, 4, 24, and 20 PFA applications. All ATs were terminated and noninducibility was achieved in 82 (99%) and 74 (89%) procedures, respectively. In 52 patients with >3 month follow-up, 46 (88%) patients remain in stable SR (41 / 79%) off AAD); 3 and 3 patients have paroxysmal or persistent AT. Conclusion PFA with catheter Farapulse can affect complex/epicardial AT sources resistant to RFA in prior or present ablation procedure; however, there is a certain discrepancy between high efficacy in AT terminating and medium-term clinical outcome.
Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
Pulsed field ablation (PFA) is a promising method to reduce procedure time and improve ablation safety and efficacy in all ...types of atrial fibrillation (AF).
Purpose
To present ablation approach and medium-term outcomes of PFA in all AF types.
Methods
Between 9/2021-10/2022, PFA using Farawave catheter was performed in 250 patients (63±11 years, 65 females). Patients with paroxysmal AF were basically scheduled for simple pulmonary vein isolation (PVI) (Farawave, ICE), patients with longstanding AF (LSPAF) underwent complex left atrial (LA) PFA (Farawave, CS 10-pole catheter, ICE); ablation extent varied in persistent AF.
Results
Paroxysmal AF (n=131; 115 ablated in SR), persistent AF (n=39; 11 ablated in SR), and LSPAF (n=64) were ablated with procedure times 58±20, 105±28, and 116±32 minutes, respectively, and fluoroscopy times 9±5, 14±7, and 17±7 minutes, respectively. Additional 16 patients underwent PFA for atrial tachycardia (AT). Ongoing AF was terminated by PFA in 13/16 (81%), 16/28 (57%), and 23/64 (36%) patients with paroxysmal AF, persistent AF, and LSPAF, respectively. In groups of paroxysmal AF ablated in SR, paroxysmal AF ablated in AF, persistent AF ablated in SR, persistent AF, and LSPAF, simple PVI was performed in 100%, 50%, 73%, 11%, and 0 patients respectively; and freedom from AF/AT was present in 86/99 (87%), 11/14 (79%), 7/10 (70%), 11/12 (92%), and 40/52 (77%) patients, respectively, of total 187 patients with follow-up ≥3 months (≥6 months in 139 patients). In 8 patients with repeat ablation post-PFA for paroxysmal AF (n=4), persistent AF (n=2), LSPAF (n=2), extra-PV AF/AT sources dominated in all groups. Complications included one tamponade with pericardiocentesis, and prolonged ST elevation with negative coronary angiography.
Conclusion
PFA using Farawave catheter was associated with reduced procedure times and favourable medium-term outcome for all AF types. Early experience specifically suggests improved outcome after extensive LA ablation for persistent AF/LSPAF.
Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
There is a limited knowledge of immediate and long-term efficacy of pulsed field ablation for residual atrial tachycardia ...(AT) following (longstanding) persistent atrial fibrillation (AF) ablation and resistant to prior radiofrequency ablation (RFA).
Purpose
To present immediate effects of PFA (Farapulse) in a series of patients with repeat ablation for residual atrial tachycardia (AT) resistant to prior RFA.
Methods and results
In 5-11/2022, of 23 patients scheduled for PFA, 19 patients (64±7 years, 3 females) underwent PFA for left atrial (LA) AT resistant to RFA in first (n=4), second (n=11), third (n=3), and fourth (n=1) repeat ablation, respectively, after primary persistent AF ablation (4 patients were redirected to RFA for septal/right atrial AT source found by 3D mapping). At the procedure onset, persistent AT was ongoing (n=15) or was induced (n=4; AF induced and subsequently converted into AT in 3 patients). Mapping/ablation strategy was directed according to CS activation/entrainment to: 1) no 3D mapping and direct PFA (n=11); 2) PFA directly after 3D LA mapping (n=5); 3) PFA following RFA after 3D LA mapping (n=3). Total of 29 ATs was found (1,2, and 3 ATs in 12, 4, and 3 patients, respectively). Localized AT sources (n=16) dominated over macroreentry (MR) ATs (8 perimitral, 4 roof-dependent, 1 typical flutter). Only MR ATs, only localized ATs, and both MR+localized ATs were present in 7, 4, and 8 patients, respectively. All ATs were stopped with 5±9 PFA applications at the site of AT source and remained non-inducible. In 3 patients with initial ineffective RFA (6, 11, 6 minutes) within the same procedure, subsequent PFA terminated the AT with 1, 4, and 1 application respectively. Procedure and fluoroscopy times were 104±29 and 12±4 minutes, no complication occurred.
Conclusion
PFA with catheter Farapulse can affect complex/epicardial AT sources resistant to RFA in prior or present ablation procedure.
Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
Benefits of pulsed field ablation (PFA) compared to radiofrequency ablation (RFA) are not known in patients with ...longstanding persistent atrial fibrillation (LSPAF).
Purpose
To present interim procedural and short-term clinical results of an ongoing prospective randomized comparison of PFA vs. RFA in patients with LSPAF.
Methods
In 9/2021-10/2022, 125 patients underwent catheter ablation for LSPAF using PFA (n=64, 69±8 years, 11 F, continuous AF 32±20 months) vs. RFA (n=61, 68±8 years, 17 F, continuous AF 29±23 months). PFA included pulmonary vein isolation (PVI) and extra-PV left atrial (LA) ablation. RFA included stepwise PVI, electrogram-guided LA ablation, CS isolation, and electrogram-guided right atrial ablation. Intermediate endpoints were PVI, mitral isthmus, LA roof and CTI blocks); sinus rhythm (SR) restoration by ablation was the desired procedural endpoint. Follow-up included 7-day ECG monitoring every 3 months during the first year, and every 6 months afterwards.
Results
In groups PFA vs. RFA, procedure and fluoroscopy times were 116±32 vs. 204±44 minutes, and 17±5 vs. 8±2 minutes, respectively (both p<0.001). AF termination (into intermediate AT or directly into SR) and SR restoration by ablation were achieved in 30 (47%) vs. 42 (69%) patients (p=0,19), and in 23 (36%) vs. 35 (57%) patients (p=0,15). Of those 48 vs. 50 patients with follow-up ≥3 months (≥6 months in 37 vs. 39 patients), freedom from any AF/AT (>30 s) was achieved in 38 (79%) vs. 23 (46%) patients.
Conclusion
Interim results of ongoing comparison suggest procedure time reduction and improved AF/AT free survival after PFA as compared to RFA in patients with LSPAF.
Abstract
Aims
Despite all this technical progress, VT recurrence after unipolar ablation remains relatively high (12–47%). Bipolar ablation has been proposed as an appealing solution, which may ...overcome boundaries associated with unipolar ablation settings. Therefore, we have proposed an animal study to compare bipolar (BPA) vs sequential unipolar ablation (UPA) using a contact-force sensing technology on both catheters.
Methods
20 large white female pigs (6 months-old, 60–70kg) underwent multiple RF ablations (30W, 60s, 30ml/min irrigation) on ventricular myocardium, from epicardial and endocardial sides. After the procedure, the animal underwent euthanasia, cardioplegia and organ excision. The hearts were fixed and underwent high-resolution cardiac MRI. Each lesion was characterized primarily in terms of volume, depth, width and transmurality.
Results
We evaluated 35 lesions across the intraventricular septum. No difference in volume, linear dimensions and impedance drop was observed in this area, between the two ablation settings. However, for the generation of unipolar lesions, twice the ablation time was needed. Transmurality of the lesions shows a trend in favor of BPA. We then analyzed 73 lesions from the endocardial side and 34 from the epicardial one of the ventricular free walls. Lesion transmurality was found remarkably improved in BPA (p=0.030, OR 23.73 4.71,11.96). Ventricular BPA lesions were significantly deeper on the epicardial side (p<0.0001)
Conclusion
BPA is more likely to create transmural lesions in the ventricle, when compared to UPA. Half the time is needed for the creation of comparably deep and large lesions. BPA is specifically more effective in creating epicardial lesions.
Micromegas as a large microstrip detector for the COMPASS experiment Thers, D; Abbon, Ph; Ball, J ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2001, Letnik:
469, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Recent results on the gaseous microstrip detector Micromegas which will be used to track particles in the COMPASS experiment at CERN are presented. Developments concerning its mechanical and ...electrical design, associated readout electronics and gas mixture were carried out. Particular attention was paid to the discharge phenomenon which affects this type of microstrip detector. The adequacy of the options finally retained, especially the SFE16 readout and the use of a Ne–C
2H
6–CF
4 gas mixture, was demonstrated in a set of beam tests performed on a
26×36
cm
2
prototype. Operating at a gain of ∼6400, full efficiency is reached along with a spatial resolution of
∼50
μm
and a timing accuracy of
8.5
ns
. Discharges are kept at a low rate, less than one per SPS spill in a COMPASS-like environment. Via a decoupling of the strips through individual capacitors their impact is greatly reduced. They generate a dead time on the full detector of
∼
3
ms
, affecting marginally the detection efficiency given their rate. The probability of discharge, at a given value of efficiency, is found to decrease with the mean value of the gas mixture atomic number. In view of these results, the commissioning of Micromegas for COMPASS is foreseen in the near future.
The direct reconstruction of the pp elastic-scattering amplitudes and fixed-energy Saclay-Geneva phase shift analyses have been carried out at 1.80, 2.10, 2.40 and 2.70 GeV where complete sets of ...observables have recently been measured at SATURNE. They provide unique phase shift analysis solutions at 1.80, 2.10 and 2.40 GeV and two solutions at 2.70 GeV. Results of the direct amplitude reconstruction and the Saclay-Geneva phase shift analyses agree at all energies. Results are also compared to the Virginia Polytechnic Institute phase-shift predictions below 2.55 GeV and observed differences are discussed.
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