scholarly journals A novel local impedance algorithm and contact force sensing to guide high power short duration radiofrequency ablation is efficient and safe for circumferential pulmonary vein isolation

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
J Schreieck ◽  
D Heinzmann ◽  
C Scheckenbach ◽  
M Gawaz ◽  
M Duckheim

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Local impedance (LI) drop can predict sufficient lesion formation during radiofrequency ablation (RF). Recently, a novel ablation catheter technology able to measure LI and contact force has been made available for clinical use. High power short duration (HPSD) RF ablation has been shown to be feasible for atrial fibrillation (AF) ablation with short procedure time. We used LI drop and plateau formation to guide duration of 50 Watt RF power applications for circumferential pulmonary vein isolation (PVI). Methods Consecutive patients with indication for de novo AF ablation (n = 32, age 65 ± 10 years) with paroxysmal (n = 16) or persistent (n = 16) AF underwent ultra high density 3D mapping of the left atrium and catheter ablation. Thereafter, ipsilateral PV encircling with 50 Watt RF-applications targeting an interlesion distance of ≤ 6mm and a contact force of 10-30g was performed. Duration of HPSD RF application between 7-15s was guided by impedance drop >20 Ohm and plateau formation of LI. Further ablation strategy was left to the investigator’s discretion. Esophageal temperature measurement was performed using a three thermistor catheter with temperature cut off 39.0°C. In case of temperature rise or very near esophageal contact to the circumferential line, RF application time was shortened to 7s. Patients underwent adenosine testing after PVI. Previously we performed all types of AF ablation using an LI guided HPSD ablation without contact force measurement capability in 80 patients. Results Complete PVI was achieved in all pts with only 13.5 ± 4.3 min cumulative RF application duration and an ablation procedure duration of 46.5 ± 10.4 min with the novel LI measuring catheter. First-pass isolation of ipsilateral veins was achieved in 75% of circles. Recurrence of PV conduction during waiting period (20min) and adenosine testing occured in 25% of circles, and was reablated in most patients with a single spot of HPSD application. Using 94 ± 36 RF application per patient, mean maximum LI drop was 23.6 ± 4.0 Ohm. Reconnected fibers were associated with low LI drop due to instability of contact in most cases due to breathing in case of difficult sedation of the patients. No serious complications occurred in all 32 pts using HPSD with the novel contact force catheter design. Conclusion Guiding of HPSD RF ablation by LI is highly efficient and safe. A novel local impedance algorithm in combination with contact force sensing enable short PVI times with low early recurrence of PV conduction. Prediction of permanent lesions seems possible and the only limitation seems to be unstable RF catheter contact due patients breathing. Follow up have to be waited.

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
CH Heeger ◽  
MS Sano ◽  
RMS Meyer-Saraei ◽  
CE Eitel ◽  
HL Phan ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation for atrial fibrillation (AF) treatment provides effective and durable PVI associated with encouraging clinical outcome. The novel QDot ablation catheter with Qmode + ablation mode (90W/4sec, Figure 1) offers the ability to possibly improve safety and decrease ablation procedure times. Aims We aim to evaluate safety and efficacy of the very high-power short-duration (vHP-SD) temperature-controlled radiofrequency (RF) ablation Qmode + mode for pulmonary vein isolation (PVI) utilizing the novel QDot micro ablation catheter. The data was compared to conventional power-controlled ablation index (AI) guided PVI. Methods Twenty-five consecutive patients with paroxysmal or persistent AF were prospectively enrolled, underwent vHP-SD based PVI (vHP-SD group) and were compared to 25 consecutive patients treated with conventional CF-sensing catheters (control). Results All PVs were successfully isolated utilizing Qmode +. The total median RF ablation time was vHP-SD: 334 (282, 369) sec. vs control: 1567 (1250, 1756) sec. (p < 0.0001), the median procedure time was vHP-SD: 56 (48-62) vs. control: 104 (92-122) min (p < 0.0001). No differences in periprocedural complications were observed. Conclusions The novel Qmode + provides safe and effective PVI with impressive short RF time and short procedures times. Procedure time and RF time were substantial lower in the vHP-SD group. Abstract Figure 1


2021 ◽  
Author(s):  
Joey Junarta ◽  
Sean J. Dikdan ◽  
Naman Upadhyay ◽  
Sairamya Bodempudi ◽  
Michael Y. Shvili ◽  
...  

Abstract Introduction High-power short-duration (HPSD) ablation is a novel strategy using contact force-sensing catheters optimized for radiofrequency ablation for atrial fibrillation (AF). No study has directly compared HPSD versus standard-power standard-duration (SPSD) contact force-sensing settings in patients presenting for repeat ablation with AF recurrence after initial ablation. Methods We studied consecutive cases of patients with AF undergoing repeat ablation with SPSD or HPSD settings after their initial pulmonary vein isolation (PVI) with temperature controlled non-contact force, SPSD or HPSD settings between 6/23/14 and 3/4/20. Procedural data collected included radiofrequency ablation delivery time (RADT). Clinical data collected include sinus rhythm maintenance post-procedure. Results A total of 61 patients underwent repeat ablation (36 SPSD, 25 HPSD). A total of 51 patients (83.6%) were found to have pulmonary vein reconnections necessitating repeat isolation, 10 patients (16.4%) had durable PVI and ablation targeted non-PV sources. RADT was shorter when comparing repeat ablation using HPSD compared to SPSD (22 vs 35 min; p = 0.01). There was no difference in sinus rhythm maintenance by Kaplan–Meier survival analysis (log rank test p = 0.87), after 3 or 12-months between groups overall, and when stratified by AF type, left atrial volume index, CHA2DS2-VASc score, or left ventricular ejection fraction. Conclusion We demonstrated that repeat AF ablation with HPSD reduced procedure times with similar sinus rhythm maintenance compared to SPSD in those presenting for repeat ablation.


2021 ◽  
Author(s):  
Kaihao Gu ◽  
Shengjie Yan ◽  
Xiaomei Wu

Abstract Background: High power-short duration ablation is an emerging conception for cardiac RF treatment. But the biophysical ablation properties of this technique have not been fully explored. This study compared the electric field characteristics and thermal lesion dimension in High power-short duration (HP-SD) radio frequency (RF) ablation and standard RF ablation by using the finite element method. Results: The results demonstrated that the lesion size and temperature in HP–SD RF ablation increased faster than standard RF ablation. The thermal lesion volume in both ablation modes demonstrated a linear increase and the rate of increase of HP–SD RF ablation grew faster than that of standard RF ablation. For HP–SD application at 50 W for 5 s, the lesion depth was shallower (1.74 to 2.1 mm vs 2.40 to 3.15 mm) and the surface lesion diameter was broader (2.76 to 3.32 mm vs 2.42 to 2.66 mm) than that for standard RF ablation at 25 W for 30 s. Conclusion: Compared with standard RF ablation, HP–SD RF ablation creates a broader lesion width and surface lesion diameter but shallower lesion depth, with a faster increase in temperature. HP–SD ablation is more able to achieve uniform and contiguous lesion shape, which is a suitable for point-to-point RF ablation procedures.Higher temperature was formed in deeper space of cardiac tissue in HP–SD ablation. The duration of HP–SD ablation should be strictly controlled for preventing the steam occur in tissue.


2020 ◽  
Vol 13 (9) ◽  
Author(s):  
Zak Loring ◽  
DaJuanicia N. Holmes ◽  
Roland A. Matsouaka ◽  
Anne B. Curtis ◽  
John D. Day ◽  
...  

Background: Catheter ablation is an increasingly used treatment for symptomatic atrial fibrillation (AF). However, there are limited prospective, nationwide data on patient selection and procedural characteristics. This study describes patient characteristics, techniques, treatment patterns, and safety outcomes of patients undergoing AF ablation. Methods: A total of 3139 patients undergoing AF ablation between 2016 and 2018 in the Get With The Guidelines-Atrial Fibrillation registry from 24 US centers were included. Patient demographics, medical history, procedural details, and complications were abstracted. Differences between paroxysmal and patients with persistent AF were compared using Pearson χ 2 and Wilcoxon rank-sum tests. Results: Patients undergoing AF ablation were predominantly male (63.9%) and White (93.2%) with a median age of 65. Hypertension was the most common comorbidity (67.6%), and patients with persistent AF had more comorbidities than patients with paroxysmal AF. Drug refractory, paroxysmal AF was the most common ablation indication (class I, 53.6%) followed by drug refractory, persistent AF (class I, 41.8%). Radiofrequency ablation with contact force sensing was the most common ablation modality (70.5%); 23.7% of patients underwent cryoballoon ablation. Pulmonary vein isolation was performed in 94.6% of de novo ablations; the most common adjunctive lesions included left atrial roof or posterior/inferior lines, and cavotricuspid isthmus ablation. Complications were uncommon (5.1%) and were life-threatening in 0.7% of cases. Conclusions: More than 98% of AF ablations among participating sites are performed for class I or class IIA indications. Contact force-guided radiofrequency ablation is the dominant technique and pulmonary vein isolation the principal lesion set. In-hospital complications are uncommon and rarely life-threatening.


Heart Rhythm ◽  
2020 ◽  
Vol 17 (8) ◽  
pp. 1223-1231 ◽  
Author(s):  
Roger A. Winkle ◽  
R. Hardwin Mead ◽  
Gregory Engel ◽  
Melissa H. Kong ◽  
Jonathan Salcedo ◽  
...  

Author(s):  
Hagai D. Yavin ◽  
Zachary P. Bubar ◽  
Koji Higuchi ◽  
Jakub Sroubek ◽  
Mohamed Kanj ◽  
...  

Background: High-power short-duration (HP-SD) radiofrequency ablation (RFA) has been proposed as a method for producing rapid and effective lesions for pulmonary vein isolation. The underlying hypothesis assumes an increased resistive heating phase and decreased conductive heating phase, potentially reducing the risk for esophageal thermal injury. The objective of this study was to compare the esophageal temperature dynamic profile between HP-SD and moderate-power moderate-duration (MP-MD) RFA ablation strategies. Methods: In patients undergoing pulmonary vein isolation, RFA juxtaposed to the esophagus was delivered in an alternate sequence of HP-SD (50 W, 8–10 s) and MP-MD (25 W, 15–20 s) between adjacent applications (distance, ≤4 mm). Esophageal temperature was recorded using a multisensor probe (CIRCA S-CATH). Temperature data included magnitude of temperature rise, maximal temperature, time to maximal temperature, and time return to baseline. In swine, a similar experimental design compared the effect of HP-SD and MP-MD on patterns of esophageal injury. Results: In 20 patients (68.9±5.8 years old; 60% persistent atrial fibrillation), 55 paired HP-SD and MP-MD applications were analyzed. The esophageal temperature dynamic profile was similar between HP-SD and MP-MD ablation strategies. Specifically, the magnitude of temperature rise (2.1 °C [1.4–3] versus 2.0 °C [1.5–3]; P =0.22), maximal temperature (38.4 °C [37.8–39.3] versus 38.5 °C [37.9–39.4]; P =0.17), time to maximal temperature (24.9±7.5 versus 26.3±6.8 s; P =0.1), and time of temperature to return to baseline (110±23.2 versus 111±25.1 s; P =0.86) were similar between HP-SD and MP-MD ablation strategies. In 6 swine, esophageal injury was qualitatively similar between HP-SD and MP-MD strategies. Conclusions: Esophageal temperature dynamics are similar between HP-SD and MP-MD RFA strategies and result in comparable esophageal tissue injury. Therefore, when using a HP-SD RFA strategy, the shorter application duration should not prompt shorter intervals between applications.


EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
K Kassa ◽  
Z Nagy ◽  
B Kesoi ◽  
Z Som ◽  
C Foldesi ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Introduction In recent times, high-power short-duration (HPSD) radiofrequency ablation (RFA) has emerged as an alternative strategy for pulmonary vein isolation (PVI) in atrial fibrillation (AF). Purpose We aimed to compare HPSD approach and conventional, ablation-index (AI) guided PVI using contact force sensing ablation catheters in respect of efficacy, safety, procedural characteristics, and outcome. Methods A total of 184 consecutive AF patients with first PVI were enrolled (age: 60 ± 11 years, paroxysmal: 56.5%, persistent: 43.5%) between November 2016 and December 2019. An ablation protocol of 50W energy with 15-20 g contact force was used for a duration of 8-12 sec based on the loss of capture concept in the HPSD group (n = 91) meanwhile, PVI was achieved according to the conventional power settings (posterior wall 25W, AI: 400, anterior wall 35W, AI: 550 ) in the control group (n = 93). During 1-year follow-up, documented AF for more than 30 seconds was considered as recurrence. Results Radiofrequency time and procedural time were significantly shorter using HPSD ablation (26.0 ± 12.7 min vs. 42.9 ± 12.6 min, p < 0.001, and 91 ± 30.1 min vs. 105.3 ± 28 min, p < 0.001). The HPSD strategy significantly lowered fluoroscopy time and radiation dose (5.47 ± 4.07 min vs. 8.15 ± 10.04 min, p = 0.019, and 430.2 ± 534.06 cGycm2 vs. 604.2 ± 633.9 cGycm2, p = 0.046). The HPSD group showed significantly less arrhythmia recurrence during 1-year follow-up with 76.9% of patients free from AF compared to 66.7% in the control group (p = 0.037). No pericardial tamponade, periprocedural thromboembolic complication, or atrio-oesophageal fistula occurred in the HPSD group. We observed 2 pericardial tamponade and 1 periprocedural stroke in the control group. Conclusions HPSD RFA for AF was demonstrated to be safe, and lead to significantly improved 1-year outcome in our mixed patient population. HPSD protocol significantly shortened procedural and radiofrequency time with decreased fluoroscopy time and radiation exposure.


Author(s):  
Atsushi Suzuki ◽  
H. Immo Lehmann ◽  
Songyun Wang ◽  
Kay Parker ◽  
Kristi Monahan ◽  
...  

Introduction: The spatial thermodynamics of very high power-short duration (vHPSD) radiofrequency (RF) application during pulmonary vein isolation (PVI) in in-vivo model has not been well characterized. This study was conducted to investigate the distance-temperature relationship during vHPSD-RF ablation. Methods: PVI was performed using the vHPSD catheter with the settings of 90W, RF time of 4 sec and 15mL/min irrigation in a canine model. Catheter contact force (CF) of 10-20g was defined as ‘normal’ and CF >20g as ‘firm’ CF. Tissue temperature was monitored using thermocouples implanted at the surface of the left atrial-pulmonary vein junction, left phrenic nerve, and the luminal esophagus. PVI using a standard contact-force sensing catheter (SCF) (settings of 35W, 30sec and 30mL/min irrigation) was performed for comparison. Results: A total of 334 TC profiles in 4 animals was investigated. Time to maximum tissue temperature (MTT) (6.0sec [vHPSD/normal CF] vs. 30.5 sec [SCF/normal CF], p<0.001; 8.0sec [vHPSD/firm CF] vs. 24.0sec [SCF/firm CF], p=0.022) was shorter with vHPSD than in SCF groups. MTT within 10mm from catheter-tip was lower in vHPSD ablation with normal CF than using SCF ablation (median 41.9°C [interquartile-range; 40.2-46.1] vs. 49.5°C [45.9-56.2], p=0.013). The distance margin to keep the MTT below 39ºC, 42ºC, and 50ºC were 4.9mm, 4.2mm, and 3.4mm, respectively in the vHPDS group. This margin was larger (8.0mm, 6.6mm, and 4.6mm) in the SCF group. Conclusion: Our study underscores that vHPSD creates greater resistive heating than conventional catheter ablation.


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