Background: Modulation of the cardiac autonomic nervous system (ANS) is a promising adjuvant therapy in the treatment of atrial fibrillation (AF). In pre-clinical models, pulsed field (PF) energy has the advantage of selectively ablating the epicardial ganglionated plexi (GP) that govern the ANS. Objective: This study aims to demonstrate the feasibility and safety of epicardial ablation of the GPs with PF during cardiac surgery with a primary efficacy outcome of prolongation of the atrial effective refractory period (AERP).  Methods: In a single-arm, prospective analysis, patients with or without a history of AF underwent epicardial GP ablation with PF during coronary artery bypass grafting (CABG). AERP was determined immediately pre- and post- GP ablation to assess cardiac ANS function. Holter monitors were performed to determine rhythm status and Heart Rate Variability (HRV) at baseline and at 1 month post-procedure.   Conclusions:  This study demonstrates the safety and feasibility of epicardial ablation of the GP using PF to modulate the ANS during cardiac surgery. Large, randomized analyses are necessary to determine whether epicardial PF ablation can offer a meaningful impact on the cardiac ANS and reduce AF. Results: Of 24 patients, 23 (96%) received the full ablation protocol. No device-related adverse effects were noted. GP ablation resulted in a 20.7% ± 19.9% extension in AERP (P < 0.001). Post-operative AF was observed in 7 (29%) patients. Holter monitoring demonstrated an increase in mean heart rate (74.0±8.7 vs 80.6±12.3, P=0.01). There were no significant changes in HRV. There were no study-related complications.

Background: Increasing interest in physiological pacing has been countered with challenges such as accurate lead deployment and increasing pacing thresholds with His-bundle pacing (HBP). More recently, left bundle branch area pacing (LBBAP) has emerged as an alternative approach to physiologic pacing. Objective: To compare procedural outcomes and pacing parameters at follow-up during initial adoption of HBP and LBBAP at a single center. Methods: Retrospective review, from September 2016 to January 2020, identified the first 50 patients each who underwent successful HBP or LBBAP. Pacing parameters were then assessed at first follow-up after implantation and after approximately one year, evaluating for acceptable pacing parameters defined as sensing R-wave amplitude >5 mV, threshold <2.5 V @ 0.5 ms and impedance between 400 and 1200 Ohms. Results: The HBP group was younger with lower ejection fraction compared to LBBP (73.2±15.3 vs 78.2±9.2 years, p=0.047; 51.0±15.9% vs 57.0±13.1%, p = 0.044). Post-procedural QRS widths were similarly narrow (119.8±21.2 vs. 116.7±15.2ms; p = 0.443) in both groups. Significantly fewer patients with HBP met the outcome for acceptable pacing parameters at initial follow-up (56.0% vs 96.4%, p = 0.001) and most recent follow-up (60.7% vs 94.9%, p = <0.001; at 399±259 vs. 228±124 days, p = <0.001). More HBP patients required lead revision due to early battery depletion (0 vs 13.3%, at an average of 664 days). Conclusion: During initial adoption, as compared with LBBAP, HBP is associated with a significantly higher frequency of unacceptable pacing parameters, energy consumption, and lead revisions.

An 84-year-old man with persistent AF (CHA2DS2-Vasc 6) was referred because of a migrated 24-mm Watchman implanted 7 months prior. Transesophageal echo (TEE) showed device malposition and protrusion outside the LAA along with a 90º tilt and peri-device leak (Figure, Movies 1-3). Under general anesthesia, an extraction was performed using TEE, intracardiac echocardiographic and fluoroscopy. Using a femoral arterial approach, a 27-mm Watchman was positioned in ascending aorta for cerebroembolic protection, never released from the connecting wire (WAASP technique, Movies 4-5) (1). A 23-Fr non-deflectable sheath (Micra, Medtronic, MN) was advanced into right atrium, through which a 12-Fr deflectable sheath (Flexcath Advance, Medtronic) was placed transeptal. A 2.4 mm x 20 cm Raptor grasping device (US Endoscopy, Mentor, Ohio; Figure) was advanced through 12 Fr sheath to grasp the Watchman device. With sustained traction, the device was dislodged from the LAA into the 23 Fr sheath (Figure, Movie 6). A new 24 mm Watchman was then placed and the temporary Watchman in the aorta was removed. A follow up TEE showed stable position without significant peri-device leak. This case demonstrates the safety and feasibility of malpositioned Watchman extraction re-implantation in the same setting (2).

Aims: Saline-irrigated radiofrequency ablation (RFA) for atrial fibrillation (AF) is limited by the absence of reliable thermal feedback limiting the utility of temperature monitoring for power titration. The DiamondTemp (DT) ablation catheter allow efficient temperature-controlled irrigated ablation. We sought to assess the 1-year clinical safety and efficacy of the DT catheter in treating drug-refractory paroxysmal AF. Methods and results: The TRAC-AF trial (NCT02821351) is a prospective, multi-center (n=4), single-arm study that enrolled patients with symptomatic, drug-refractory paroxysmal AF. Using the DT catheter, point-by-point ablation was performed around all pulmonary veins (PVs) to achieve PV isolation (PVI). Ablation was performed in a temperature-control mode (60oC, max 50 W) until the split-tip EGM amplitude decreased by ≤75%. The primary efficacy endpoints included acute procedural success and freedom from AF at 12 months. A total of 62 patients (age 60.3 ± 11.4 years; 60% male) were evaluated after AF ablation using the DT catheter. The mean fluoroscopy and RF ablation times were 9.4±6.4 min and 19.8±8.6 min, respectively. Acute isolation of all PVs was achieved in 100% of patients. There were no steam pops and there were not seen any char or caugulum on the catheter tip after ablation. There were very few serious procedure/device-related adverse events including a single case of cardiac tamponade (1.6%). At 1 year, the freedom from AF was 74.2%. Conclusion: This first in man series demonstrates that temperature-controlled irrigated RFA with the DT catheter is efficient, safe, and effective in the treatment of paroxysmal AF.