P1447Use of novel local impedance-based catheter in typical right atrial flutter ablation: preliminary data from a multicenter Italian study

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
V Ducceschi ◽  
C Pandozi ◽  
A Arestia ◽  
L Rossi ◽  
G Bencardino ◽  
...  
Keyword(s):  
Atrial Flutter ◽  
Conduction Block ◽  
Right Atrial ◽  
Rf Ablation ◽  
Lesion Formation ◽  
Tissue Impedance ◽  
Novel Technology ◽  
Before And After ◽  
Acute Success ◽  
Tissue Characteristics

Abstract Funding Acknowledgements NO FUNDING Background Many studies demonstrated the importance of an optimal tissue contact to obtain safe and effective lesions and to improve the clinical outcome in ablation of cavotricuspid isthmus (CTI) for typical right atrial flutter (AFL). Data about a novel technology able to measure local tissue impedance (LI) providing a measure of tissue characteristics and lesion formation is still lacking in right atrium or CTI working. Purpose This analysis explores the relationship between LI measures and ablation spot lesion locations during ablation of CTI in common AFL patients (pts). Methods Consecutive pts undergoing AFL ablation from the CHARISMA registry were included. A novel RF ablation catheter with dedicated algorithm (DirectSense - DS -) was used to measure LI at the distal electrode of this catheter. Each targeted spot was characterized in terms of LI parameters during RF delivery at the lateral, intermediate and posterior portions of the CTI. Successful single RF ablation was defined according with a reduction of voltage (RedV) by at least 50% or split in two separate potentials (SPL). Ablation endpoint was the creation of bidirectional conduction block across the isthmus. Results A total of 135 ablation spot lesions were delivered in 20 pts (median 5 [3-11] lesions per pt): 7 (5%) at lateral, 88 (65%) at intermediate and 40 (30%) at posterior portions of the CTI. Acute success was obtained in all cases and no complications were observed. The median ablation time was 26 [17 – 36] seconds per lesion. 100 (74%) and 51 (38%) ablation spots were effective according with RedV or SPL, respectively. The mean LI was 106 ± 15Ω prior to ablation and 93 ± 13Ω after ablation (p < 0.0001, mean absolute LI drop 14 ± 7Ω, mean percentage LI drop 13%±6). Effective ablation spots showed a higher absolute impedance drop (15 ± 7Ω at effective RedV vs 9.6 ± 8Ω at ineffective RedV, p = 0.0001; 15.6 ± 7Ω at effective SPL vs 12.5 ± 7Ω at ineffective SPL, p = 0.0173) or % impedance drop (14%±6 at effective RedV vs 9%±7 at ineffective RedV, p < 0.0001; 14.5%±6 at effective SPL vs 11.6%±6 at ineffective SPL, p = 0.0103) compared with ineffective sites. No significant differences were found in terms of starting LI, ending LI or LI drop among CTI areas. The percentage of LI drop was associated both with RedV (odd ratio 1.17 (95%CI: 1.08 to 1.26, p = 0.0001)) and with SPL (odd ratio 1.08 (1.02 to 1.14, p = 0.0132)). Conclusion In our preliminary experience, measured LI before and after RF delivery and LI drop appear to be consistent and homogeneous across different CTI ablation locations. The magnitude of the LI drop was associated with effective lesion formation and conduction block.

scholarly journals Optimized radiofrequency lesions through local impedance guidance for effective cavo-tricuspid isthmus ablation in typical right atrial flutter: data from the CHARISMA registry

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
V Ducceschi ◽  
A Carbone ◽  
G Botto ◽  
G Nigro ◽  
C Lavalle ◽  
...  
Keyword(s):  
Atrial Flutter ◽  
Conduction Block ◽  
Right Atrial ◽  
Complete Agreement ◽  
Tissue Impedance ◽  
Funding Sources ◽  
Radiofrequency Lesions ◽  
The Mean ◽  
Mean Time ◽  
Funding Acknowledgements

Abstract Funding Acknowledgements Type of funding sources: None. Background Radiofrequency (RF) catheter ablation of the cavo-tricuspid isthmus (CTI) is an established treatment for typical right atrial flutter (RAFL). However, whether local tissue impedance (LI) is able to predict effective CTI ablation and what LI drop values during ablation should be used to judge a lesion as effective remains to be established. Purpose We aimed to investigate the ability of LI to predict ablation efficacy in patients (pts) with RAFL and to characterize the CTI in terms of LI. Methods Consecutive pts undergoing RAFL ablation from the CHARISMA registry were enrolled at 9 centers. A novel RF ablation catheter with dedicated algorithm (DirectSense - DS -) was used to measure LI at the distal electrode of this catheter. RF applications (RFC) were targeted to a minimum LI drop of 10 Ω within 30 seconds and were stopped when a maximum cutoff LI drop of <40 Ω was observed. Successful single RFC was defined according with a split in two separate potentials (SPL), reduction of voltage (RedV) by at least 50% or changes at unipolar EGM (UPC). Agreement among criteria was evaluated. Ablation endpoint was the creation of bidirectional conduction block (BDB) across the isthmus. Results A total of 279 ablation spot lesions were delivered in 30 pts (mean RFC 9 ± 6 lesions per pt): 106 (38%) at anterior, 115 (41%) at mid and 58 (21%) at posterior portions of the CTI. BDB was obtained in all cases and no complications were observed. The median RFC delivery time was 30 [19–45] seconds per lesion. 132 (47%), 150 (54%) and 86 (31%) ablation spots were effective according with SPL, RedV and UPC, respectively. Complete agreement of all the criteria was reached in 70% of the cases. The mean LI was 104.4 ± 11Ω prior to ablation and 92.1 ± 11Ω after ablation (p < 0.0001, mean absolute LI drop 12.2 ± 7Ω, mean time to LI drop 13 ± 8 seconds). Effective ablation spots showed a higher LI drop compared with ineffective sites at each single criteria (16.6 ± 7Ω vs 8.3 ± 4Ω for SPL, p < 0.0001; 16.1 ± 6Ω vs 7.8 ± 5Ω at for RedV, p < 0.0001; 19 ± 6Ω vs 9.2 ± 4Ω for UPC, p < 0.0001) and LI drop values significantly increase according to the number of criteria satisfied (ranging from 7.5Ω % -no criteria- to 19.1 -all criteria-). A 15Ω cut-off value for LI (AUC 0.91, sensitivity = 67%, specificity = 92%, p < 0.0001) was associated with the achievement of all criteria with an OR of 21.9 (95%CI: 11.1 to 43.5, p < 0.0001) and a positive predictive value of 76%. Starting LI and LI drop seem to be higher at mid-septal areas. Conclusion In our preliminary experience, a LI-guided approach of CTI seems to be safe and effective in RAFL ablation. The magnitude of LI drop was associated with effective lesion formation and conduction block and could be used as a marker of ablation efficacy.

scholarly journals Feasibility and efficacy using the KODEX-EPD imaging system in right atrial flutter ablation: a single center experience

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
V Schillaci ◽  
G Stabile ◽  
G Shopova ◽  
A Arestia ◽  
A Agresta ◽  
...  
Keyword(s):  
Atrial Flutter ◽  
Imaging System ◽  
Conduction Block ◽  
Right Atrial ◽  
Atrial Pacing ◽  
Funding Sources ◽  
Single Center Experience ◽  
Typical Atrial Flutter ◽  
Procedural Time

Abstract Background Isthmus-dependent right atrial flutter is the most frequently encountered atrial flutter in clinical practice (80–90% of atrial flutters). Purpose The aim of our study was to assess as first experience the feasibility and safety of radiofrequency catheter ablation (RFCA) of cavo-tricuspid isthmus (CTI) guided by KODEX-EPD imaging system in patients presenting with typical atrial flutter (AFL). Methods 16 consecutive patients (mean age 68,46±7,8 years, 80% males) with diagnosis of AFL underwent RFCA guided by KODEX-EPD imaging system. In 15 patients the analysis performed during tachycardia showed a counter-clockwise activation. In 1 patient no tachycardia could be induced and the ablation was performed in sinus rhythm with fixed pacing from the coronary sinus. The KODEX-EPD imaging system was also used to guide ablation and to confirm persistent bidirectional block after ablation. Results Mean procedural time was 37,6±8,2 min, mean radiofrequency ablation time was 7,8±3,4 min, and mean fluoroscopy time was 2,1±1,2 min. All procedures were acutely successful with interruption of AFL during RFCA along the inferior CTI in 15 patients and achievement of the bidirectional conduction block in 16 patients proven by atrial pacing medial and lateral to the ablation line. There were no major procedural and 30-day complications. Over a mean follow-up of 18 months, we observed no recurrence of arrhythmia and no complications. Conclusions Our study shows that RFCA for AFL using the KODEX-EPD imaging system is feasible, safe, and effective. FUNDunding Acknowledgement Type of funding sources: None.

P-wave morphology during right atrial pacing before and after atrial flutter ablation—A new marker for success

1997 ◽  
Vol 79 (10) ◽  
pp. 1417-1420 ◽  
Author(s):  
Mohamed H. Hamdan ◽  
Jonathan M. Kaiman ◽  
Hal V. Barron ◽  
Michael D. Lesh
Keyword(s):  
Atrial Flutter ◽  
P Wave ◽  
Right Atrial ◽  
Atrial Pacing ◽  
Before And After ◽  
Wave Morphology ◽  
Atrial Flutter Ablation

A novel local impedance algorithm to guide effective pulmonary vein isolation in AF patients: 1-year outcome from the CHARISMA Study

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
L Segreti ◽  
A De Simone ◽  
V Schillaci ◽  
G Zucchelli ◽  
C Pandozi ◽  
...  
Keyword(s):  
Time Course ◽  
De Novo ◽  
Holter Monitoring ◽  
Rf Ablation ◽  
Tissue Impedance ◽  
Local Tissue ◽  
Spot Center ◽  
Rf Applications ◽  
Tissue Characteristics

Abstract Background Recently, a novel technology able to measure local tissue impedance (LI) providing a measure of tissue characteristics aimed at validating confidently ablation endpoints has become available for clinical use. Purpose We report the outcomes of our acute and long-term clinical evaluation of this algorithm in consecutive atrial fibrillation ablation cases. Methods Consecutive patients (pts) undergoing AF ablation at 6 Italian centers were included in the CHARISMA registry. A novel RF ablation catheter and a dedicated algorithm were used to measure LI through the distal catheter's electrode. The ablation was guided by looking at the magnitude and time course of impedance drop during RF delivery. The maximum distance between each ablation spot (center-to-center) was suggested to be ≤4 mm. RF applications were targeted to a LI drop of 10 Ω and RF applications were stopped when a maximum cutoff LI drop of <40 Ω was observed. Successful single RF ablation was defined according with a reduction of signal voltage (RedV) by at least 50% and inability to capture local tissue on pacing. Ablation endpoint was PVI as assessed by entrance and exit block. Post-ablation, all pts were monitored with ambulatory event monitoring, as well as Holter monitoring at 3, 6, and 12 months post-ablation. Additional ECG monitoring was performed as indicated by patient symptoms. Results A total of 1914 point by point first pass RF applications >10 s performed around PVs were analyzed from 98 pts (mean age = 61±11 years, 69% male, 55% paroxysmal AF, 45% persistent AF, 60% de novo procedures, 40% redo procedures). The mean LI was 105±15Ω prior to ablation and 92±13Ω after ablation (p<0.0001, mean absolute LI drop of 12.7±8Ω) during a median RF delivery time of 22 [17–31] sec. Effective ablation spots (88%) showed a higher absolute impedance drop (13.6±8Ω at effective RedV vs 6±3Ω at ineffective RedV, p<0.0001) compared with ineffective sites (12%). No steam pops or complications, including atrio-esophageal fistula or tamponade were reported during or after the procedures. At the end of the procedures all PVs were successfully isolated in all study pts. During a median follow-up of 369 [287–446] days, 13 pts (13.2%) developed an AF/AT recurrence after the 90-days blanking period (9.2% with paroxysmal vs 18% with persistent AF, p=0.239; 8.5% for de novo vs 20.5% for redo procedures, p=0.127). The time to recurrence was comparable among AF type (HR=1.97; 0.66 to 5.86; log-rank p=0.2265 for persistent vs paroxysmal AF) and procedural type (HR=2.56; 0.84 to 7.82; log-rank p=0.087 for redo vs de novo procedure) Conclusions In our experience, the magnitude of the LI drop during RF delivery was associated with effective lesion formation. An ablation strategy for PVI guided by LI technology was safe and effective, and resulted in a very low recurrence rate of AF at 1-year follow-up irrespective of paroxysmal/persistent AF type or de novo/redo procedure. Funding Acknowledgement Type of funding source: None

Acute Success and Persistence of Bidirectional Conduction Block in the Cavotricuspid Isthmus One Month Post Cryocatheter Ablation of Common Atrial Flutter

2006 ◽  
Vol 29 (2) ◽  
pp. 146-152 ◽  
Author(s):  
MALTE KUNISS ◽  
KLAUS KURZIDIM ◽  
HARALD GREISS ◽  
ALEXANDER BERKOWITSCH ◽  
JOHANNES SPERZEL ◽  
...  
Keyword(s):  
Atrial Flutter ◽  
Conduction Block ◽  
Cavotricuspid Isthmus ◽  
Acute Success

scholarly journals Concomitant real-time measurement and correlation of contact force to baseline local impedance and local impedance drops in RF ablation of left and right atrial procedures

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
L Riesinger ◽  
J Siebermair ◽  
S Kochhaeuser ◽  
E Pesch ◽  
S R Popal ◽  
...  
Keyword(s):  
Real Time ◽  
Atrial Flutter ◽  
Contact Force ◽  
Time Measurement ◽  
Right Atrial ◽  
Strong Positive Correlation ◽  
Rf Ablation ◽  
Gap Formation ◽  
Positive Correlation ◽  
Real Time Measurement

Abstract Introduction Radiofrequency (RF) ablation is performed in various arrhythmias. Still, arrhythmia recurrence is a challenging problem, not only in atrial fibrillation (AF). One reason for arrhythmia recurrence is suspected to be due to remaining gaps. Measurement of local impedance (LI) and change of LI during RF application can be used as a predictor and surrogate for successful ablation. Another tool, used for the last couple of years, estimating sufficient tissue contact is provided by catheters with real-time contact force (CF) measurement. The new INTELLANAV STABLEPOINT™ catheter by Boston Scientific was recently introduced combing both strategies. We sought to investigate the parallel measurement and correlation of LI and CF in real-time during left atrial (LA) and right atrial (RA) procedures. Methods We included the first n=20 patients who underwent LA ablation for AF or atypical atrial flutter and n=7 patients who underwent RA procedures for atrial flutter or atrial tachycardia and analysed retrospectively procedural data. For every RF delivery RF duration, CF, baseline LI, minimal LI, LI drop, as well as minimal LI and LI drop after 5 and 10 sec was documented. Only RF deliveries with stable contact (ablation without delay) were included. We then correlated baseline LI to LI drop (maximum, after 5 sec, after 10 sec) and to the documented CF at baseline. Results A total of 27 procedures was analysed. In total, 777 RF deliveries (663 in LA, 114 in RA) were documented with a mean RF duration of 21.7 sec. Mean baseline LI was 148.4 Ω, minimal LI 130.6Ω, LI after 5 sec 135.0 Ω and LI after 10sec 132.5 Ω. Mean complete LI drop was 17.8 Ω (13.4 Ω after 5 sec, 15.8 Ω after 10 sec). Mean CF was 15.5g. We could see a significant positive correlation between average CF and LI drop (p<0.01) (figure 1A), as well as between average CF and LI drop after 5 sec (p<0.01) and after 10 sec (p<0.01). Also, for baseline LI we could see a significant strong positive correlation to LI drop (p<0.001) (figure 1B), LI drop after 5 sec (p<0.001) and after 10 sec (p<0.001). Baseline LI did not correlate to average CF. Baseline LI was significantly higher in RA, when compared to LA (152.5Ω vs. 147.7Ω; p<0.05). LI drop did not differ between RA and LA procedures (17.8Ω vs. 17.7Ω), whereas mean RF duration per RF application was significantly longer in LA compared to RA procedures (22.8sec vs. 15.3sec; p<0.001) and applied CF was also higher in LA compared to RA procedures (16.0Ω vs. 12.8Ω; p<0.001). Conclusion Parallel real-time measurement of LI and CF is providing further insights into ablation biophysics. Based on these results the CF values might provide a prediction of subsequent lesion formation. A combination with LI measurement seems to be useful to prevent insufficient lesions, predisposing to gap formation and associated with arrhythmia recurrence, but also to potentially guarantee a higher safety by visualizing the applied CF and consecutive LI drop. FUNDunding Acknowledgement Type of funding sources: None. Figure 1

Characterization of Low Right Atrial Isthmus as the Slow Conduction Zone and Pharmacological Target in Typical Atrial Flutter

Circulation ◽  
1997 ◽  
Vol 96 (8) ◽  
pp. 2601-2611 ◽  
Author(s):  
Ching-Tai Tai ◽  
Shih-Ann Chen ◽  
Chern-En Chiang ◽  
Shih-Huang Lee ◽  
Kwo-Chang Ueng ◽  
...  
Keyword(s):  
Atrial Flutter ◽  
Right Atrial ◽  
Slow Conduction ◽  
Typical Atrial Flutter ◽  
Pharmacological Target ◽  
Conduction Zone

Real-time local impedance monitoring to assess tissue lesion during pulmonary vein isolation: a new tool for AF ablation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Di Cori ◽  
L Segreti ◽  
G Zucchelli ◽  
S Viani ◽  
F Tarasco ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Contact Force ◽  
Vascular Complications ◽  
Lesion Formation ◽  
Tissue Impedance ◽  
Af Ablation ◽  
Group 2 ◽  
Group 1

Abstract Background Contact force catheter ablation is the gold standard for treatment of atrial fibrillation (AF). Local tissue impedance (LI) evaluation has been recently studied to evaluate lesion formation during radiofrequency ablation. Purpose Aim of the study was to assess the outcomes of an irrigated catether with LI alghorithm compared to contact force (CF)-sensing catheters in the treatment of symptomatic AF. Methods A prospective, single-center, nonrandomized study was conducted, to compare outcomes between CF-AF ablation (Group 1) and LI-AF ablation (Group 2). For Group 1 ablation was performed using the Carto 3© System with the SmartTouch SF catheter and, as ablation target, an ablation index value of 500 anterior and 400 posterior. For Group 2, ablation was performed using the Rhythmia™ System with novel ablation catheter with a dedicated algorithm (DirectSense) used to measure LI at the distal electrode of this catheter. An absolute impedance drop greater than 20Ω was used at each targeted. According to the Close Protocol, ablation included a point by point pulmonary vein isolation (PVI) with an Inter-lesion space ≤5 mm in both Groups. Procedural endpoint was PVI, with confirmed bidirectional block. Results A total of 116 patients were enrolled, 59 patients in Group 1 (CF) and 57 in Group 2 (LI), 65 (63%) with a paroxismal AF and 36 (37%) with a persistent AF. Baseline patients features were not different between groups (P=ns). LI-Group showed a comparable procedural time (180±89 vs 180±56, P=0.59) but with a longer fluoroscopy time (20±12 vs 13±9 min, P=0.002). Wide antral isolation was more often observed in CF-Group (95% vs 80%, P=0.022), while LI-Group 2 required frequently additional right or left carina ablation (28% vs 14%, P=0.013). The mean LI was 106±14Ω prior to ablation and 92.5±11Ω after ablation (mean LI drop of 13.5±8Ω) during a median RF time of 26 [19–34] sec for each ablation spot. No steam pops or complications during the procedures were reported. The acute procedural success was 100%, with all PVs successfully isolated in all study patients. Regarding safety, only minor vascular complications were observed (5%), without differences between groups (p=0.97). During follow up, 9-month freedom from atrial fibrillation/atrial flutter/atrial tachycardia recurrence was 86% in Group 1 and 75% in Group 2 (P=0.2). Conclusions An LI-guided PV ablation strategy seems to be safe and effective, with acute and mid-term outcomes comparable to the current contact force strategy. LI monitoring could be a promising complementary parameter to evaluate not only wall contact but also lesion formation during power delivery. Procedural Outcomes Funding Acknowledgement Type of funding source: None

Lipomatous Hypertrophy of the Intraatrial Septum Resulting in Right Atrial Inflow Obstruction and Atrial Flutter

2010 ◽  
Vol 89 (5) ◽  
pp. 1647-1649 ◽  
Author(s):  
Jennifer A. Dickerson ◽  
Macy Smith ◽  
Steven Kalbfleisch ◽  
Michael S. Firstenberg
Keyword(s):  
Atrial Flutter ◽  
Right Atrial ◽  
Lipomatous Hypertrophy
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