Practical Guide on the Use of the PulseSelect Pulsed Field Ablation System for Atrial Fibrillation Ablation Procedures

Figures

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  Figure 1. The pulse select ablation system. The system consists of an ablation generator, which delivers a biphasic bipolar waveform, a 10F deflectable sheath, and a multielectrode 25 mm diameter circular array. The array is designed with a 20° forward tilt, with the centre electrode (electrode 5) being in the most forward position. The ablation catheter has a central lumen which can accommodate a 0.81 mm/0.032 inch J-tip guidewire (Image reproduced with permission from Medtronic).

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  Figure 2. Contact assessment. Ablation catheter—tissue contact assessment via fluoroscopy (A), intracardiac echocardiography (B), and electroanatomic mapping (C).

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  Figure 3. Fluoroscopic visualization of PulseSelect ablation catheter. Catheter position and array geometry in each of the left superior (LSPV), left inferior (LIPV), right superior (RSPV), and right inferior (RIPV) pulmonary veins in the anteroposterior (AP), left anterior oblique (LAO), and right anterior oblique (RAO) projections.

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  Figure 4. Array visualization in the distal, ostial, and antral positions. In the distal or ostial position, the circular array is often ‘compressed’ by the narrower circumference of the tubular pulmonary vein, with a degree of compression that is greater distally. When viewed ‘en-face’ the support struts often cross as electrodes 1 and 9 approximately. When the array is positioned in an antral position there is a noticeable widening of the distance between electrodes 1 and 9, and their corresponding struts.

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  Figure 5. Array visualization in the ostial, and antral positions on electroanatomic mapping system, with lesion tags projected on the pre-ablation voltage map. Pictures are the posteroanterior, left lateral, and right lateral projections.

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  Figure 6. Achieving contact with the circular array in areas of anatomical challenge. Fluoroscopic and electroanatomical map appearance of ablation catheter position for lesions targeting the Roof (A), left atrial appendage ridge (B), right carina (C), and left carina (D). For the roof (A), the wire is placed in the right superior pulmonary vein, and the loop is positioned at the antral location with electrode 5 cranial and towards the midline. The curvature on the sheath is then relaxed, prolapsing the array towards the roof. For the ridge (B), the wire is placed in the left superior pulmonary vein, and the loop is positioned with electrode 5 anterior at the LAA ridge. The catheter and sheath are rotated counterclockwise, and the catheter is advanced into the pulmonary vein, prolapsing the array anterior towards the appendage. For the carina (C and D), coverage can be obtained by rotating the array towards the contralateral pulmonary vein (PV) with concomitant sheath deflection. For the inferior PV this involves placing the wire in the superior vein, positioning electrode 5 inferiorly in the carina, then applying sheath deflection. For the superior PV, the process is reversed, with the…

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  Figure 7. Posterior wall isolation. Posterior wall isolation can be achieved through the delivery of sequential overlapping lesions. With the guidewire secured within the pulmonary vein the catheter is rotated to bring electrode 5 in opposition to the posterior wall with the sheath is positioned on the back of the array and rotated to prolapse the array on the posterior wall. After each pulsed field ablation application, the system is retracted and then rotated to re-engage the posterior wall tissue with the goal of maintaining approximately 50% overlap in the array for ideal posterior wall coverage. Typically, the lesions are repeated with the guidewire in the superior and inferior pulmonary vein, to deliver two adjacent linear lesions.

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  Figure 8. Cavotricuspid isthmus ablation. Depicted are two approaches to CTI ablation with the PulseSelect Catheter. The left panel demonstrates the ‘circular’ approach, whereby the CTI is engaged with the inferior or posterior aspect of the array (e.g. electrode 5 positioned at the ventricular aspect, combined with sheath deflect), The right panel demonstrates the ‘linear’ approach, whereby the distal 4–5 array electrodes are extended from the deflectable sheath with the slide in the advanced (forward) position. The sheath is then maximally deflected to lay the array across the isthmus.

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  Figure 9. Superior vena cava isolation. Electroanatomic map (top panels) and fluoroscopy (bottom panels) depicting the PulseSelect catheter position and lesion location for an SVC isolation.

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  Figure 10. Anterior wall ablation. Electroanatomic map depicting the presence of an atypical left atrial flutter circuit (left panel). Linear ablation across the anterior wall resulted in arrhythmia termination and bidirectional block (right panel).