B-Po03-131 Effects of Contact Force on Lesion Size During Pulsed Field Ablation

Nakagawa, Hiroshi; Castellví, Quim; Neal, Robert E.; Girouard, Steven D.; Ikeda, Atsushi; Kuroda, Shunsuke; Hussein, Ayman A.; Saliba, Walid; Wazni, Oussama

doi:10.1016/j.hrthm.2021.06.605

Cited by 29 publications

(37 citation statements)

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“…However, we know that for RFA differences in contact force can cause changes in the contact area between the heart tissue and the catheter tip, thus, modifying the impedance between the tip of the catheter and the tissue and the eventual lesion created 35 . For PFA, recent studies have also shown the impact of contact force for different application approaches 36 , 37 . In Supplementary Materials, the importance and complexity of contact in lesion formation for both techniques was assessed for a “worst case” contact scenario.…”

Section: Resultsmentioning

confidence: 99%

A computational comparison of radiofrequency and pulsed field ablation in terms of lesion morphology in the cardiac chamber

Gómez-Barea

García-Sánchez

Ivorra

2022

Sci Rep

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Pulsed Field Ablation (PFA) has been developed over the last years as a novel electrical ablation technique for treating cardiac arrhythmias. It is based on irreversible electroporation which is a non-thermal phenomenon innocuous to the extracellular matrix and, because of that, PFA is considered to be safer than the reference technique, Radiofrequency Ablation (RFA). However, possible differences in lesion morphology between both techniques have been poorly studied. Simulations including electric, thermal and fluid physics were performed in a simplified model of the cardiac chamber which, in essence, consisted of a slab of myocardium with blood in motion on the top. Monopolar and bipolar catheter configurations were studied. Different blood velocities and catheter orientations were assayed. RFA was simulated assuming a conventional temperature-controlled approach. The PFA treatment was assumed to consist in a sequence of 20 biphasic bursts (100 µs duration). Simulations indicate that, for equivalent lesion depths, PFA lesions are wider, larger and more symmetrical than RFA lesions for both catheter configurations. RFA lesions display a great dependence on blood velocity while PFA lesions dependence is negligible on it. For the monopolar configuration, catheter angle with respect to the cardiac surface impacted both ablation techniques but in opposite sense. The orientation of the catheter with respect to blood flow direction only affected RFA lesions. In this study, substantial morphological differences between RFA and PFA lesions were predicted numerically. Negligible dependence of PFA on blood flow velocity and direction is a potential important advantage of this technique over RFA.

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Section: Resultsmentioning

confidence: 99%

A computational comparison of radiofrequency and pulsed field ablation in terms of lesion morphology in the cardiac chamber

Gómez-Barea

García-Sánchez

Ivorra

2022

Sci Rep

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“…It was thus shown in 21 that contact presence plays a role in ablation zone, with contact force also having a meaningful impact, albeit less sensitive than for RF ablation. Changes in electrode orientation will depend on the geometry of the catheter, including active electrode F I G U R E 4 Representative acute (>2 h) gross pathology results from the three energy settings.…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, the motile nature of the ventricles makes contact force markedly less stable. However, tested contact force was limited to a range of 15–25 g, and since PEFs were gated to the R‐wave, the deliveries were synchronized to be delivered while the ventricles are in systole, providing more consistent contact force during PEF delivery 21 …”

Section: Study Limitationsmentioning

confidence: 99%

Characteristics of pulsed electric field cardiac ablation porcine treatment zones with a focal catheter

Neal¹,

Evans²,

Castellví³

et al. 2022

Cardiovasc electrophysiol

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Objectives Pulsed electric field (PEF) therapies employ punctuated energy delivery to kill cells in a volume of tissue through mechanisms that are not dependent on thermal processes. A key component to successful cardiac ablation procedures is ensuring the generation of transmural, contiguous ablation zones, which requires in‐depth knowledge regarding treatment sizes for a given therapeutic application. Methods In this study, a series of acute treatments were delivered to porcine ventricles, where triphenyl tetrazolium chloride (TTC) vitality stain was used to identify treatment effect sizes for the three focal monopolar CENTAURI PEF cardiac ablation energy settings. Results Treatment depths were 5.7, 7.2, and 8.2 mm for the 19, 22, and 25 A energy settings, respectively. Gross pathology indicated umbral zones of hemorrhage surrounded by pale avital TTC‐negative‐negative tissue, which contrasted significantly from radiofrequency ablation (RF) controls. Histologically, treatment zones are identified by regions of contraction band necrosis and cardiomyocytolysis, which contrasted with RF control lesions composed primarily of coagulation necrosis. Conclusions Together, these data indicate the ability for focal monopolar PEF treatments to generate deep treatment zones in cardiac ablation without incurring the gross or histological coagulative characteristics of RF thermal lesions.

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“…Existing preclinical work has indicated that heavily trabeculated appendages can be ablated in a durable, transmural manner with a circular PFA catheter, providing indirect evidence that PFA may result in lesions without direct electrode-tissue contact. 16 Recently, Nakagawa et al 21 reported no lesions when a focal catheter (3.5 mm irrigated TactiCath SE, Abbott) was ≈2 mm from the endocardium after PFA (Centauri, Galaxy Medical) when used in conjunction with electro-anatomical mapping and a unipolar PFA ablation system. Nevertheless, the well-controlled electrode-tissue proximity used in our study provides direct evidence of the ability of a biphasic, bipolar PFA system to create cardiac lesions in a beating heart ex vivo in the 0 mm offset distance case.…”

Section: Discussionmentioning

confidence: 99%

Effects of Electrode-Tissue Proximity on Cardiac Lesion Formation Using Pulsed Field Ablation

Howard

Tzou

Mattison

et al. 2022

Circ: Arrhythmia and Electrophysiology

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Background: Pulsed field ablation (PFA) is a novel energy modality for treatment of cardiac arrhythmias. The impact of electrode-tissue proximity on lesion formation by PFA has not been conclusively assessed. The objective of this investigation was to evaluate the effects of electrode-tissue proximity on cardiac lesion formation with a biphasic, bipolar PFA system. Methods: PFA was delivered on the ventricular epicardial surface in an isolated porcine heart model (n=8) via a 4-electrode prototype catheter. An offset tool was designed to control the distance between electrodes and target tissue; deliveries were placed 0 mm (0 mm offset), 2 mm (2 mm offset), and 4 mm away from the tissue (4 mm offset). Lesions were assessed using tetrazolium chloride staining. Numerical models for the experimental setup with and without the offset tool validated and supported results. Results: Cardiac lesion dimensions decreased proportional to the distance between epicardial surface and electrodes. Lesion depth-averaged 4.3±0.4 mm, 2.7±0.4 mm, and 1.3±0.4 mm for the 0, 2, and 4 mm and lesion width averaged 9.4±1.1 mm, 7.5±0.8 mm and 5.8±1.4 mm for the 0, 2, and 4 mm offset distances, respectively. Numerical modeling matched ex vivo results well and predicted lesion creation with and without the offset tool. Conclusions: Using a biphasic, bipolar PFA system resulted in cardiac lesions even in the 0 mm offset distance case. The relationship between lesion depth and offset distance was linear, and the deepest lesions were created with 0 mm offset distance, that is, with electrodes in contact with tissue. Therefore, close electrode-tissue proximity increases the likelihood of achieving transmural lesions by maximizing the electric field penetration into the target tissue.

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B-Po03-131 Effects of Contact Force on Lesion Size During Pulsed Field Ablation

Cited by 29 publications

References 0 publications

A computational comparison of radiofrequency and pulsed field ablation in terms of lesion morphology in the cardiac chamber

A computational comparison of radiofrequency and pulsed field ablation in terms of lesion morphology in the cardiac chamber

Characteristics of pulsed electric field cardiac ablation porcine treatment zones with a focal catheter

Effects of Electrode-Tissue Proximity on Cardiac Lesion Formation Using Pulsed Field Ablation

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