Fluoroless Workflow for Pulsed Field Ablation of Atrial Fibrillation Using the Sphere-9 and VARIPULSE Catheters

Figures

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  Figure 1. Intracardiac echocardiography (ICE) assessment of the left atrial appendage (LAA) from the right ventricular outflow tract (RVOT) view, ruling out left atrial appendage thrombus prior to ablation. The RVOT view is obtained when the standard right atrial ICE window is inadequate. This step is performed at the start of every fluoroless procedure as part of the pre-ablation safety assessment. RVOT, right ventricular outflow tract; LAA, left atrial appendage.

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  Figure 2. Fluoroless transseptal puncture under intracardiac echocardiography (ICE) and CARTO 3 guidance. Septal tenting at the mid-posterior, slightly inferior portion of the interatrial septum (arrow) with the radiofrequency-enabled VersaCross wire advanced across the interatrial septum into the left atrium (arrowhead).

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  Figure 3. Right atrial electroanatomical map created with the OCTARAY catheter on CARTO 3 prior to left atrial mapping. Tagged landmarks: superior vena cava–right atrial junction, inferior vena cava–right atrial junction, tricuspid annulus, and coronary sinus ostium. The VIZIGO steerable sheath (arrow) is directly visualized on the map, enabling fluoroless navigation.

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  Figure 4. Three-dimensional left atrial reconstruction with catheters in situ on the CARTO 3/VARIPULSE system (posteroanterior view, left panel; superior/roof view, right panel). Key structures are labeled: decapolar catheter, coronary sinus catheter, left superior pulmonary vein, left inferior pulmonary vein, right superior pulmonary vein, and right inferior pulmonary vein. This anatomical reconstruction is created by combining SOUNDSTAR ICE catheter imaging via the CARTOSOUND FAM module with fast anatomical mapping using the OCTARAY catheter and provides the navigational foundation for all subsequent fluoroless left atrial catheter manipulation and ablation.

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  Figure 5. Introduction of the VARIPULSE variable-loop circular catheter into the left atrium via the VIZIGO sheath under CARTO 3 and ICE guidance. The catheter is unsheathed in the mid-left atrial cavity, with the loop diameter adjusted between 25 and 35 mm for optimal pulmonary vein engagement. Labels identify the ostium of pulmonary veins, VARIPULSE catheter, and VIZIGO steerable sheath.

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  Figure 6. Pulsed field ablation delivery with the VARIPULSE catheter using the TRUPULSE generator. (A) Circumferential applications around the pulmonary vein ostium and antrum with systematic catheter rotation, with CS catheter and mitral valve annulus labeled. (B) Completed circumferential lesion set (purple tags) marking all applied ablation points around the pulmonary veins, ensuring contiguous coverage. The arrow marks the junction between electrodes 1 and 10, where spatial gaps are most likely to occur.

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  Figure 7. Post-ablation remapping of the pulmonary vein antra and ostia with the OCTARAY high-density mapping catheter, confirming entrance and exit block. Purple indicates ablated low-voltage tissue; arrow marks a residual conduction gap subsequently targeted with an additional application. ICE verifies the anatomical position of the mapping catheter relative to the pulmonary vein ostium.

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  Figure 8. Right atrial electroanatomical map created with the Sphere-9 lattice-tip catheter on the Affera mapping system prior to transseptal puncture. Tagged landmarks include the SVC-RA junction, IVC RA junction, His bundle, tricuspid annulus, and CS ostium.

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  Figure 9. Coronary sinus catheter placement under combined Sphere-9 mapping and ICE guidance on the Affera mapping system. The coronary sinus catheter (CS Catheter, arrow) serves as a stable anatomical and electrical reference throughout the procedure.

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  Figure 10. Simultaneous display of the Sphere-9 lattice-tip catheter and the VIZIGO bidirectional steerable sheath on the Affera three-dimensional map, obtained during a fluoroless procedure at the authors’ institution. The Affera/Prism system localizes devices by hybrid magnetic and calibrated-impedance (“synergy”) navigation and, per the manufacturer’s system documentation, provides visualization of non-sensor-based diagnostic catheters [75]. That documentation addresses diagnostic catheters rather than sheaths; no comparative outcome data on sheath visualization exist for this platform, and the image is presented as an illustration of our workflow.

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  Figure 11. High-density left atrial and pulmonary vein voltage map acquired with the Sphere-9 lattice-tip catheter on the Affera mapping system. The nine mini-electrodes and integrated sensors enable delineation of the: left atrial appendage, pulmonary vein ostia, left atrial ridge, pulmonary vein antra, and posterior wall, with real-time impedance-based contact assessment.

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  Figure 12. Dual-energy lesion delivery with the Sphere-9 lattice-tip catheter. (A) Pulsed field applications delivered circumferentially around the pulmonary vein antra, with real-time impedance-based contact indication. (B) Completed cavotricuspid isthmus line created with the same catheter without catheter exchange, using both energy sources: temperature-controlled radiofrequency applications (red tags) in the segment adjacent to the tricuspid annulus, where pulsed field energy is avoided, and pulsed field applications (green tags) along the remainder of the isthmus toward the inferior vena cava. The yellow ring marks the currently selected lesion tag. Images were obtained on the Affera mapping system during a procedure performed at the authors’ institution.