Controlling pulsed field ablation efficacy during ablation procedures

Figures

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  Figure 1. A) Defined vectors delivered between catheter electrodes. B) A singular group with biphasic pulses separated by interphase (d1) and interpulse (d2) delays. C) A single packet, P, is typically delivered per heartbeat and is assembled by vectors that deliver groups in specified orders. The series of predefined packets, P, constitutes an application.

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  Figure 2. 2025 EHRA survey detailing intraprocedural workflows with respect to imaging. During the procedure, half of the 160 respondents relied solely on fluoroscopy, while the remainder variably used 3D electroanatomical mapping systems, intracardiac echocardiography, and atrial angiography. Adapted from Bergonti et al.1 3D, three-dimensional; CT, computed tomography; ICE, intracardiac echocardiography; LA, left atrium; PFA, pulsed field ablation; PVI, pulmonary vein isolation.

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  Figure 3. Assessment of catheter-tissue contact using ICE. A and B) Two petals of the pentaspline catheter (arrow) are in the RIPV as demonstrated by fluoroscopy and ICE imaging. C) After gentle clockwise rotation, the petals are rotated outside the RIPV, but there is suboptimal contact (asterisk). D and E) After advancement of the pentaspline catheter and the sheath electrode–tissue contact is optimized as demonstrated by ICE imaging (D) and the backflip sign of the petals on fluoroscopy (E). Images are courtesy of Dr Khan Mahmoodi (Erasmus MC). ICE, intracardiac echocardiography; RIPV, right inferior pulmonary vein

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  Figure 4. 3D anatomical mapping using the CARTOSOUND FAM MAP Module. A) Using the SOUNDSTAR ICE catheter, several frames are acquired from each left atrial structure, including the left atrial appendage and pulmonary veins, both from the right atrium and right ventricular outflow tract. Using a deep learning algorithm, an anatomical FAM shell is reconstructed from the acquired frames. B and C) This reconstructed shell can be used to navigate the variable loop catheter towards the antral side of each pulmonary vein. There is a good correlation of the position of the PFA catheter on ICE imaging (B) and the FAM shell (C). Images are courtesy of Dr Yuri Blaauw (UMCG). ICE, intracardiac echocardiography; PFA, pulsed field ablation

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  Figure 5. Two-way interactions between voltage, number of applications, and contact force and their effect on lesion depth. Among voltage, number of applications, and CF, two separate interactions were identified as having an effect on lesion depth. A) Examines the interaction between voltage and the number of applications at a fixed CF of 25 g, while B) evaluates the interaction between CF and the number of applications at a fixed voltage of 2.0 kV. A) At low voltages, the number of applications has little effect on lesion depth. However, at higher voltages, lesion depth increases with more applications. The lines indicate the predicted lesion depth for four applications and one application across varying voltage levels. B) With only one application, contact force strongly influences lesion depth, with higher force (35–45 g) producing deeper lesions than lower force (5–15 g). However, when four applications are applied, the effect of contact force on lesion depth is reduced. Adapted from Younis et al. Factors influencing lesion titration in a monopolar PFA point catheter: a preclinical study, Circ Arrhythm Electrophysiol. 2026;19:e014157. CF, contact force; PFA, pulsed field ablation

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  Figure 6. Main acute electrogram morphology changes observed immediately after PFA delivery. Adapted from Amorós-Figueras G, et al. Dynamics of High-Density Unipolar Epicardial Electrograms During PFA. Circ Arrhythm Electrophysiol. 2023 Sep;16(9):e011914. PFA, pulsed field ablation

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  Figure 7. Illustrative examples of specific electrophysiological responses to reversible PF delivered at the critical isthmus. A) Non-propagated reversible PF delivered at the left atrial posterior wall leading to tachycardia termination. B) Non-propagated reversible PF delivered at cavotricuspid isthmus leading to stable tachycardia cycle length prolongation. PF, pulsed-field