Systematic Characterization of High-Power Short-Duration Ablation: Insight From an Advanced Virtual Model

Background: High-power short-duration (HPSD) recently emerged as a new approach to radiofrequency (RF) catheter ablation. However, basic and clinical data supporting its effectiveness and safety is still scarce.Objective: We aim to characterize HPSD with an advanced virtual model, able to assess lesion dimensions and complications in multiple conditions and compare it to standard protocols.Methods: We evaluate, on both atrium and ventricle, three HPSD protocols (70 W/8 s, 80 W/6 s, and 90 W/4 s) through a realistic 3D computational model of power-controlled RF ablation, varying catheter tip design (spherical/cylindrical), contact force (CF), blood flow, and saline irrigation. Lesions are defined by the 50°C isotherm contour. Ablations are deemed safe or complicated by pop (tissue temperature >97°C) or charring (blood temperature >80°C). We compared HPSD with standards protocols (30–40 W/30 s). We analyzed the effect of a second HPSD application.Results: We simulated 432 applications. Most (79%) associated a complication, especially in the atrium. The three HPSD protocols performed similarly in the atrium, while 90 W/4 s appeared the safest in the ventricle. Low irrigation rate led frequently to charring (72%). High-power short-duration lesions were 40–60% shallower and smaller in volume compared to standards, although featuring similar width. A second HPSD application increased lesions to a size comparable to standards.Conclusion: High-power short-duration lesions are smaller in volume and more superficial than standards but comparable in width, which can be advantageous in the atrium. A second application can produce lesions similar to standards in a shorter time. Despite its narrow safety margin, HPSD seems a valuable new clinical approach.

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P565First characterization of high-power short-duration radiofrequency ablation with remote magnetic navigation assistance

EP Europace ◽

10.1093/europace/euaa162.317 ◽

2020 ◽

Vol 22 (Supplement_1) ◽

Author(s):

G Caluori ◽

E Odehnalova ◽

J Krenek ◽

T Jadczyk ◽

M Pesl ◽

...

Keyword(s):

Short Duration ◽

High Power ◽

Calibration Curve ◽

Left Ventricular ◽

Right Atrial ◽

Pathological Examination ◽

Magnetic Navigation ◽

Rf Ablation ◽

Remote Magnetic Navigation

Abstract Funding Acknowledgements MEYS- CR (ref#LQ1605 and LM2015062) Background/Introduction High-power short-duration (HPSD) radiofrequency (RF) ablation relies on the application of intense thermal fields for a carefully restricted time, in order to quickly obtain deep but precise lesions that spare the structures surrounding the heart. The approach is still under evaluation across different therapies and catheter technologies. To the present day there is no available characterization of HPSD ablation supported by remote magnetic navigation (RMN). Purpose To describe the safety issues regarding HPSD ablation in atria and ventricles with RMN systems, while characterizing the thermal lesion size and continuity in an acute closed-chest swine model. Methods The animal trial was divided in two arms (left ventricular and atrial). 10 female large white pigs (6-month-old weight 55-65 kg) were employed in each arm. Endocardial electroanatomical mapping and ablation were performed with RMN assistance to provide stable contact and flexible maneuvering. The ventricular cohort was divided in 5 power settings (30-40-50-60-70W). Multiple RF applications (10 ca./animal) were delivered until a pop occurred or up to 60s. In the atrial cohort the animals were divided by a combination of power/application time (50W/20s – 70W/10s – 90W/4s). Intracaval right atrial ablation lines and postero-lateral left atrial lines were performed in a point-by-point fashion (ca. 4mm distance). Irrigation rate was 30ml/min. The ventricular lesions were measured via software after 9.4T MRI of fixed hearts. The atrial lesions were measures during pathological examination after explanation. Results In the ventricular arm, we obtained a safety calibration curve linking the imposed power setting to the maximal time of application. The time before a pop decreased non-linearly from 60s down to 17.69 ± 8.21 s at 70W. No statistically significant differences were observed when comparing lesions depth, width and volume among the selected power settings. In the atrial arm we observed on the post-ablation maps a significant decrease of intracaval lesions (i.e. area with bipolar voltage <1.5mV) width (17.57 ± 1.89 mm for 50W/4s down to 10.16 ± 1.56 mm for 90W/4s). Pericardial, pleural and aortic damages were visible across all the employed settings, with less pronounced alterations for 90W/4s. Transmural lesions were visible both on the right and left atrium, with evident gaps for 50W/20s. Conclusion The presented work assesses for the first time the safety limits of HPSD ablation on healthy ventricular myocardium. We provide a calibration curve for faster RF ablation with comparable lesion features. Furthermore, we expanded the previously reported application in the atrium adding the benefits of stable controlled contact provided by RMN systems. We highlighted the benefits (e.g. faster, continuous and localized lesion formation) and risks for peripheral structures using HPSD ablation for supraventricular tachycardia interventions. Abstract Figure.

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In vivo biophysical characterization of very high power, short duration, temperature‐controlled lesions

Pacing and Clinical Electrophysiology ◽

10.1111/pace.14358 ◽

2021 ◽

Vol 44 (10) ◽

pp. 1717-1723

Author(s):

Giuseppe Stabile ◽

Vincenzo Schillaci ◽

Teresa Strisciuglio ◽

Alberto Arestia ◽

Alessia Agresta ◽

...

Keyword(s):

Short Duration ◽

High Power ◽

Biophysical Characterization ◽

Temperature Controlled ◽

Very High

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Spatial Thermodynamics of very High Power-Short Duration Catheter Ablation for Pulmonary Vein Isolation in an in-vivo model

10.22541/au.162065770.06236007/v1 ◽

2021 ◽

Author(s):

Atsushi Suzuki ◽

H. Immo Lehmann ◽

Songyun Wang ◽

Kay Parker ◽

Kristi Monahan ◽

...

Keyword(s):

Catheter Ablation ◽

Pulmonary Vein ◽

Short Duration ◽

Pulmonary Vein Isolation ◽

Contact Force ◽

High Power ◽

Tissue Temperature ◽

In Vivo Model ◽

Very High

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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Outcome of High‐power Short‐duration Radiofrequency Ablation in Combination with Half‐Normal Saline Irrigation for the Treatment of Atrial Fibrillation

Pacing and Clinical Electrophysiology ◽

10.1111/pace.14407 ◽

2021 ◽

Author(s):

Abhishek Maan ◽

Weeranun D. Bode ◽

E. Kevin Heist ◽

Grace Ha ◽

Anthony Carnicelli ◽

...

Keyword(s):

Atrial Fibrillation ◽

Radiofrequency Ablation ◽

Short Duration ◽

High Power ◽

Normal Saline ◽

Saline Irrigation

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Temperature controlled high power short duration ablation with 90 watts for 4 seconds: Outcome, safety, biophysical characteristics and cranial MRI findings in patients undergoing pulmonary vein isolation

10.22541/au.162308145.53421927/v1 ◽

2021 ◽

Author(s):

Marc Kottmaier ◽

Leonie Förschner ◽

Nada Harfoush ◽

Felix Bourier ◽

Sarah Mayr ◽

...

Keyword(s):

Pulmonary Vein ◽

Short Duration ◽

Pulmonary Vein Isolation ◽

High Power ◽

Tissue Temperature ◽

Neurological Deficits ◽

Cerebral Lesions ◽

Number Of Patients ◽

Cerebral Mri ◽

Temperature Controlled

Background High power short duration (HPSD) radiofrequency-ablation (RFA) is highly efficient and safe while reducing procedure and RF time in pulmonary vein isolation (PVI). The QDot-catheter is a novel contact-force ablation catheter that allows automated flow and power adjustments depending on the local tissue temperature to maintain a target temperature during 90watts/4seconds lesions. We analysed intraprocedural data and periprocedural safety using the QDot-catheter in patients undergoing PVI for paroxysmal atrial fibrillation (PAF). Methods We included n=48 patients undergoing PVI with the QDot-catheter with a temperature controlled HPSD ablation mode with 90watts/4seconds (TC-HPSD). If focal reconnection occurred besides repeat ablation the ablation mode was changed to 50watts/15seconds (QMode). N=23 patients underwent cerebral MRI to detect silent cerebral lesions. Results Mean RF-time was 8.1+/-2.8min, procedure-duration was 84.5+/-30min. The overall maximal measured catheter-tip temperature was 52.0°C +/- 4.6°C, mean overall applied current was 871mA +/-44mA and over all applied energy was 316J +/-47J. The mean local impedance-drop was 12.1 +/- 2.4 Ohms. During Adenosine challenge n=14 (29%) patients showed dormant conduction. A total of n=24 steam pops were detected in n=18 patients (39.1%), while no pericardial tamponade occurred. No periprocedural thromboembolic complications occurred, while n=4 patients (17.4%) showed silent cerebral lesion. Conclusion TC-HPSD ablation with 90watts/4seconds using the QDot-catheter led to a reduction of procedure and RF time, while no major complications occurred. Despite optimized temperature control and power adjustment steam pops occurred in a rather high number of patients, while none of them lead to tamponade or to clinical or neurological deficits.

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