PulseSelect Based Pulmonary Vein Isolation and Ablation in Patients With Atrial Fibrillation

• Trial Population All patients with symptomatic paroxysmal or persistent AF scheduled for PVI
• Treatment Patients with AF will have to receive first oral anticoagulation for 3 weeks. Thereafter all patients will be randomized either to fluoroscopy-based or EAM-based PVI by means of the PulseSelect catheter. Transesophageal echocardiography will not be necessary prior to cardioversion of catheter ablation. Oral anticoagulation will be continued until the morning of the procedure and resumed on the evening after the intervention.
• Deep sedation Patients will be under deep sedation using boluses of midazolam, fentanyl, and propofol. Sedation will be initiated with an intravenous injection of a bolus of 1 to 2 mg midazolam plus 20 to 30 mg propofol. To maintain deep sedation, additional boluses of 10 to 20 mg propofol will be administered at intervals of at least 30 seconds.
• Ablation protocol One application (4 pulse trains) is delivered at each catheter position and a minimum of 8 applications should be completed for each vein, ensuring continuous and overlapping lesions (4 ostial and 4 antral) by rotating the catheter between ablations and flexing the sheath to create overlapping lesion segments. Electrode 5, always distally located, is used as a reference during 45 degrees rotation between each ostial and antral lesion.

EAM use facilitates overlapping and reduces the possibility for gaps. The highlighted fifth electrode is used as quick real-time reference and snapshots of the array immediately prior to pulse delivery as reference for planning subsequent ablation sites.

In both groups an additional set of 4 lesions inside the pulmonary veins will be performed initially before the ostial and antral lesions.

In half patients Carto 3 Prime® 3D-EAM system (Biosense Webster, Diamond Bar CA) system will be used for visualization of the PulseSelect catheter. Initially, a multipolar catheter (PentaRay®) will be used to map the left atrium pre-ablation.

During catheter manipulation, the investigators will visualize both the full array and highlight the fifth electrode to allow for easier and faster perception of the farthest, with regard to catheter shaft, ablation area. Input to the 3D-EAM will be interrupted during energy delivery to prevent malfunction. In cases of an extreme angle of the right inferior pulmonary vein, placement of the PulseSelect catheter in the bottom part of the vein without the guidewire inside the vein may be attempted by means of 3D-EAM and targeting the fifth electrode of the catheter.

The procedural end point will be bidirectional conduction block of all pulmonary veins after a 20-minute observation period. If reconnection of a pulmonary vein is observed, repeat ablation will be performed until block is achieved.

• Follow up/EP Study All patients will be re-assessed 2 months post ablation. Changes of therapy will not be performed during the blind period of 2 months. Clinical atrial tachyarrhythmias recurrence, need for electrical cardioversion and need for hospitalization will also be recorded. A 24-hour holter will be performed 2 months post ablation.

In all patients Carto 3 Prime® 3D-EAM system (Biosense Webster, Diamond Bar CA) system will be used for remapping of the left atrium 2 months post-ablation. All veins will be reassessed for bidirectional block to confirm continued electrical isolation. Any gaps identified will be targeted and ablated with Navistar STSF ablation catheter (Biosense Webster, Diamond Bar CA).

To assess for PV reconnection and the location of gaps, a high-density voltage map will be performed with the color display range set to 0.20 to 0.50 mV as well as to 0.10 to 0.30 mV to accentuate the border zone between healthy tissue and scar for visual identification of gaps. Gaps will be classified according to each PV quarter (anterior, superior, posterior, inferior). Stored fluoroscopy and electroanatomical pamming images from the primary procedure will be used for analysis. In case of PV reconnection, we will search for the earliest activation site as a potential location of a gap. The location of gaps will be defined by PV reisolation during ablation or, in case of multiple gaps, a clear change in PV activation sequence.

In case of aberrant PV anatomy, such as a common left trunk, all PVs were assessed individually for durable isolation and are considered individual PVs in the analyses.

Study follow-up schedule: All patients will be re-assessed at least 2 months post ablation. Changes of therapy will not be performed during the blind period of 2 months. A follow up visit will be performed at least 2 months post ablation. Clinical atrial tachyarrhythmias recurrence, need for electrical cardioversion and need for hospitalization will be recorded. A 24-hour holter will also be performed 2 months post ablation. Likewise, an off-line detailed EAM analysis will be performed post remapping focused on accurate gap identification (if any).