scholarly journals Assessment of the transmural unipolar electrogram morphology change radius during contact force-guided pulmonary vein isolation using the VISITAG™ Module and CARTOREPLAY™

2018 ◽  
Author(s):  
David R. Tomlinson ◽  
Kara N. Stevens ◽  
Adam J. Streeter
Keyword(s):  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Posterior Wall ◽  
List Type ◽  
Energy Effect ◽  
Morphology Change ◽  
Atrial Ablation ◽  
Left And Right ◽  
Rf Energy ◽  
Unipolar Electrogram

AbstractAimsTo investigate the radius of transmural (TM) ablation effect at the left atrial posterior wall (LAPW) during contact force (CF)-guided pulmonary vein isolation (PVI), using pure R unipolar electrogram (UE) morphology change – a histologically validated marker of radiofrequency (RF)-induced TM atrial ablation.MethodsFollowing PVI in 24 consecutive patients (30W, continuous RF), VISITAG™ Module and CARTOREPLAY™ (Biosense Webster Inc.) RF and UE data at left and right-sided LAPW annotated sites 1 and 2 were analysed.ResultsAcutely durable PVI without spontaneous / dormant recovery was achieved following 15s and 10-11s RF, at sites 1 and 2, respectively (p<0.0001). At site 1, RS UE morphology was noted pre-ablation, with RF-induced pure R UE morphology change in 47/48 (98%). Left and right-sided second RF site annotation was at 5.8mm and 5.2mm from site 1 respectively (p=0.64), yet immediate pure R UE morphology was noted in 35/48 (73%). For second-annotated sites, 30 demonstrated inter-ablation site transition time ≤17ms; pure R UE morphology was noted at annotation onset in 22/30 (73%), with overall median time to pure R morphology change significantly shorter than at site 1 – 0.0s, versus 4.1s and 5.3s, for left and right-sided first-annotated LAPW sites, respectively (p<0.0001).ConclusionWhen the first and second-annotated LAPW RF sites were within 7mm, 73% second-annotated sites demonstrated immediate pure R UE morphology change. These analyses support a paradigm of shorter RF duration at immediately adjacent sites during continuous RF application, and may usefully inform the further development of “tailored” approaches towards CF-guided PVI.What’s known?The VISITAG™ Module and CARTOREPLAY™ permit investigations into the tissue effects of RF energy delivery in vivo, via objective annotation methodology and retrospective evaluation of histologically validated unipolar electrogram (UE) criteria for transmural (TM) atrial ablation.Greater RF energy effect is seen at left compared to right-sided first-annotated left atrial posterior wall (LAPW) sites during pulmonary vein isolation (PVI).What’s new?Following ∼15s RF delivery at first-annotated LAPW sites and aiming for ≤6mm inter-ablation site distance during continuous RF delivery, 73% second-annotated sites demonstrated immediate TM UE morphology change.At second-annotated sites, ∼10s RF resulted in acutely durable PVI in all. Greater left-sided RF energy effect was observed, not explained by differences in RF duration, mean CF or catheter position stability.The radius of TM RF effect may be determined at the LAPW following CF and VISITAG™ Module-guided PVI.

scholarly journals Transmural unipolar electrogram morphology is achieved within 7s at the posterior left atrial wall during pulmonary vein isolation: VISITAG™ Module-based lesion assessment during radiofrequency ablation

2017 ◽  
Author(s):  
David R. Tomlinson ◽  
Madison Myles ◽  
Kara N. Stevens ◽  
Adam J. Streeter
Keyword(s):  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Contact Force ◽  
Left Atrial ◽  
Biological Effects ◽  
Posterior Wall ◽  
Morphology Change ◽  
Atrial Ablation ◽  
Left Atrial Posterior ◽  
Unipolar Electrogram

AbstractAimsTo assess the occurrence of a histologically validated measure of transmural (TM) atrial ablation – pure R unipolar electrogram (UE) morphology change – at first-ablated left atrial posterior wall (LAPW) sites during contact force (CF)-guided pulmonary vein isolation (PVI).Methods and resultsExported VISITAG™ Module and CARTOREPLAY™ (Biosense Webster Inc.) UE morphology data was retrospectively analysed in 23 consecutive patients undergoing PVI under general anaesthesia. PVI without spontaneous / dormant recovery was achieved in all, employing 16.3[3.2] minutes (mean [SD]) of temperature-controlled RF at 30W. All first-ablated LAPW sites demonstrated RS UE morphology pre-ablation, with RF-induced pure R UE morphology change in 98%. Time to pure R UE morphology was significantly shorter at left-sided LAPW sites (4.9[2.1] s versus 6.7[2.5] s; p=0.02), with significantly greater impedance drop (median 13.5Ω versus 9.9Ω; p=0.003). Importantly, neither the first-site RF duration (14.9 versus 15.0s) nor the maximum ablation catheter tip distance moved (during RF) were significantly different, yet the mean CF was significantly higher at right-sided sites (16.5g versus 11.2g; p=0.002). Concurrent impedance and objectively annotated bipolar electrogram (BE) data demonstrated ~6-8Ω impedance drop and ~30% BE decrease at the time of first pure R UE morphology change.ConclusionUsing objective ablation site annotation, TM UE morphology change was typically achieved within 7s at the LAPW, with significantly greater ablative effect evident at left-sided sites. The methodology described in this report represents a novel and scientifically more rigorous foundation towards future research into the biological effects of RF ablation in vivo.Condensed abstractThrough appropriate use of the VISITAG™ Module and CARTOREPLAY™, unipolar electrogram morphology change indicative of histologically confirmed transmural atrial ablation in animal models, was proven to occur typically within 7s, during first-site contact force-guided ablation at the left atrial posterior wall during pulmonary vein isolation.

scholarly journals The role of local impedance drop in the acute lesion efficacy during pulmonary vein isolation performed with a new contact force sensing catheter—A pilot study

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257050
Author(s):  
Nándor Szegedi ◽  
Zoltán Salló ◽  
Péter Perge ◽  
Katalin Piros ◽  
Vivien Klaudia Nagy ◽  
...  
Keyword(s):  
Pilot Study ◽  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Contact Force ◽  
Posterior Wall ◽  
Anterior Wall ◽  
Force Sensing ◽  
Lesion Formation ◽  
Force Time

Introduction Our pilot study aimed to evaluate the role of local impedance drop in lesion formation during pulmonary vein isolation with a novel contact force sensing ablation catheter that records local impedance as well and to find a local impedance cut-off value that predicts successful lesion formation. Materials and methods After completing point-by-point radiofrequency pulmonary vein isolation, the success of the applications was evaluated by pacing along the ablation line at 10 mA, 2 ms pulse width. Lesions were considered successful if loss of local capture was achieved. Results Out of 645 applications, 561 were successful and 84 were unsuccessful. Compared to the unsuccessful ablation points, the successful applications were shorter (p = 0.0429) and had a larger local impedance drop (p<0.0001). There was no difference between successful and unsuccessful applications in terms of mean contact force (p = 0.8571), force-time integral (p = 0.0699) and contact force range (p = 0.0519). The optimal cut-point for the local impedance drop indicating successful lesion formation was 21.80 Ohms on the anterior wall [AUC = 0.80 (0.75–0.86), p<0.0001], and 18.30 Ohms on the posterior wall [AUC = 0.77 (0.72–0.83), p<0.0001]. A local impedance drop larger than 21.80 Ohms on the anterior wall and 18.30 Ohms on the posterior wall was associated with an increased probability of effective lesion creation [OR = 11.21, 95%CI 4.22–29.81, p<0.0001; and OR = 7.91, 95%CI 3.77–16.57, p<0.0001, respectively]. Conclusion The measurement of the local impedance may predict optimal lesion formation. A local impedance drop > 21.80 Ohms on the anterior wall and > 18.30 Ohms on the posterior wall significantly increases the probability of creating a successful lesion.

scholarly journals Standardized pulmonary vein isolation workflow to enclose veins with contiguous lesions: the multicentre VISTAX trial

EP Europace ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1645-1652
Author(s):  
Mattias Duytschaever ◽  
Johan Vijgen ◽  
Tom De Potter ◽  
Daniel Scherr ◽  
Hugo Van Herendael ◽  
...  
Keyword(s):  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Randomized Study ◽  
Standard Of Care ◽  
Posterior Wall ◽  
Anterior Wall ◽  
Atrial Arrhythmia ◽  
Clinical Trial Registration ◽  
First Pass

Abstract Aims To evaluate the safety and effectiveness of pulmonary vein isolation in paroxysmal atrial fibrillation (PAF) using a standardized workflow aiming to enclose the veins with contiguous and optimized radiofrequency lesions. Methods and results This multicentre, prospective, non-randomized study was conducted at 17 European sites. Pulmonary vein isolation was guided by VISITAG SURPOINT (VS target ≥550 on the anterior wall; ≥400 on the posterior wall) and intertag distance (≤6 mm). Atrial arrhythmia recurrence was stringently monitored with weekly and symptom-driven transtelephonic monitoring on top of standard-of-care monitoring (24-h Holter and 12-lead electrocardiogram at 3, 6, and 12 months follow-up). Three hundred and forty participants with drug refractory PAF were enrolled. Acute effectiveness (first-pass isolation proof to a 30-min wait period and adenosine challenge) was 82.4% [95% confidence interval (CI) 77.4–86.7%]. At 12-month follow-up, the rate of freedom from any documented atrial arrhythmia was 78.3% (95% CI 73.8–82.8%), while freedom from atrial arrhythmia by standard-of-care monitoring was 89.4% (95% CI 78.8–87.0%). Freedom fromrepeat ablations by the Kaplan–Meier analysis was 90.4% during 12 months of follow-up. Of the 34 patients with repeat ablations, 14 (41.2%) demonstrated full isolation of all pulmonary vein circles. Primary adverse event (PAE) rate was 3.6% (95% CI 1.9–6.3%). Conclusions The VISTAX trial demonstrated that a standardized PAF ablation workflow aiming for contiguous lesions leads to low rates of PAEs, high acute first-pass isolation rates, and 12-month freedom from arrhythmias approaching 80%. Further research is needed to improve the reproducibility of the outcomes across a wider range of centres. Clinical trial registration: ClinicalTrials.gov, number NCT03062046, https://clinicaltrials.gov/ct2/show/NCT03062046.

P1415Wide antral circumferential pulmonary vein isolation ablation using a novel balloon cryoablation catheter

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
A P Martin ◽  
M Fowler ◽  
N Lever
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrium ◽  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Paroxysmal Atrial Fibrillation ◽  
Left Atrial ◽  
Pulmonary Veins ◽  
Posterior Wall ◽  
The Novel ◽  
Median Treatment

Abstract Background Pulmonary vein isolation using cryotherapy is an established treatment for the management of patients with paroxysmal atrial fibrillation. Ablation using the commercially available balloon cryocatheter has been shown to create wide antral pulmonary vein isolation. A novel balloon cryocatheter (BCC) has been designed to maintain uniform pressure and size during ablation, potentially improving contact with the antral anatomy. The extent of ablation created using the novel BCC has not previously been established. Purpose To determine the anatomical extent of pulmonary vein isolation using electroanatomical mapping when performing catheter ablation for paroxysmal atrial fibrillation using the novel BCC. Methods Nine consecutive patients underwent pre-procedure computed tomography angiography of the left atrium to quantify the chamber dimensions. An electroanatomical map was created using the cryoablation system mapping catheter and a high definition mapping system. A bipolar voltage map was obtained following ablation to determine the extent of pulmonary vein isolation ablation. A volumetric technique was used to quantify the extent of vein and posterior wall electrical isolation in addition to traditional techniques for proving entrance and exit block. Results All patients had paroxysmal atrial fibrillation, mean age 56 years, 7 (78%) male. Electrical isolation was achieved for 100% of the pulmonary veins; mean total procedure time was 109 min (+/- 26 SD), and fluoroscopy time 14.9 min (+/- 2.4 SD). The median treatment applications per vein was one (range one - four), and median treatment duration 180 sec (range 180 -240). Left atrial volume 32 mL/m2 (+/- 7 SD), and mean left atrial posterior wall area 22 cm2 (+/- 4 SD). Data was available for quantitative assessment of the extent of ablation for eight patients. No lesions (0 of 32) were ostial in nature. The antral surface area of ablation was not statistically different between the left and right sided pulmonary veins (p 0.63), which were 5.9 (1.6 SD) and 5.4 (2.1 SD) cm2 respectively. In total 50% of the posterior left atrial wall was ablated.  Conclusion Pulmonary vein isolation using a novel BCC provides a wide and antral lesion set. There is significant debulking of the posterior wall of the left atrium. Abstract Figure.

664Local catheter impedance drop during pulmonary vein isolation predicts conduction block in patients with paroxysmal atrial fibrillation: initial results of the LOCALIZE clinical trial

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
M Das ◽  
A Luik ◽  
E Shepherd ◽  
M Sulkin ◽  
J Laughner ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Roc Analysis ◽  
De Novo ◽  
Conduction Block ◽  
Posterior Wall ◽  
Mapping Procedure ◽  
Index Procedure ◽  
First Pass

Abstract Funding Acknowledgements Boston Scientific Background Radiofrequency (RF) catheter ablation for pulmonary vein isolation (PVI) requires resistively heating cardiac tissue to create conduction block. Creation of an RF lesion results in an impedance drop and the magnitude of this drop depends on the temperature and amount of myocardium being heated. Pre-clinical and clinical evaluation of an advanced local impedance (LI) metric found that greater LI drops were indicative of more effective lesion formation. Purpose To evaluate whether LI drop is associated with conduction block after first pass encirclement of the PVs in patients with paroxysmal AF. Methods LOCALIZE is an ongoing, single-arm, multi-center clinical trial (clinicaltrials.gov NCT03232645). LOCALIZE consists of an index PVI procedure (results presented here) and a 3-month follow-up mapping procedure. In the index procedure, electroanatomical maps of the left atrium were created and ipsilateral PVs were divided into 8 anatomical segments (n = 16 per patient). PVI was performed using point-by-point ablation with blinding of operators to LI. Following initial encirclement and a 20-minute wait period, coronary sinus-paced electroanatomical maps were created to identify gaps within anatomical segments. Gaps were annotated on the map and subsequently ablated. Mean LI drop within each segment was calculated offline as an estimate of regional RF energy delivery (Figure - Left). The diagnostic accuracy of LI drop for predicting segment block was assessed using receiver operating characteristic (ROC) analysis in segments with inter-lesion spacing ≤6mm. Results Forty-seven patients with paroxysmal AF underwent PVI at 5 centers (age 62 ± 11 years, male 55.3%). All patients left the index procedure with all PVs isolated. When blinded to LI (n = 3,064 ablations), median baseline LI was 106 (IQR: 97-115) Ω and median LI drop was 18.4 (12.7-24.9) Ω. After first pass encirclement, blocked segments had a significantly larger LI drop (20.2 [14.6-26.0] Ω) than segments with gaps (10.6 [6.9-15.1] Ω, p &lt; 0.01, Figure - Right). The association between LI drop and block was further evaluated along anatomical anterior/posterior wall thickness differences. Anterior block segments were found to have significantly larger LI drops (21.0 [15.9-27.2] Ω) than posterior block segments (16.6 [12.7-23.7] Ω, p &lt; 0.01). ROC analysis of segments with inter-lesion spacing ≤6mm identified optimal LI cut-off values of 16Ω in anterior segments and 11Ω posteriorly, which had positive predictive values for conduction block of 95.6% and 96.7%, respectively. Conclusions The magnitude of LI drop is predictive of acute PVI segment conduction block in patients with paroxysmal AF. The thinner posterior wall required smaller LI drops for block compared to the thicker anterior wall. With inter-lesion spacing of ≤6mm, reaching a LI drop of ≥16Ω anteriorly and ≥11Ω posteriorly was highly predictive of acute segment block in de novo PVI. Abstract Figure. Local impedance drop in de novo PVI

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