Background: High-frequency low-tidal-volume (HFLTV) ventilation is a safe and cost-effective strategy that improves catheter stability, first-pass pulmonary vein isolation, and freedom from all-atrial arrhythmias during radiofrequency catheter ablation (RFCA) of paroxysmal and persistent atrial fibrillation (AF). However, the incremental value of adding rapid-atrial pacing (RAP) to HFLTV-ventilation has not yet been determined. Objective: To evaluate the effect of HFLTV-ventilation plus RAP during RFCA of paroxysmal AF on procedural and long-term clinical outcomes compared to HFLTV-ventilation alone. Methods: Patients from the REAL-AF prospective multicenter registry, who underwent RFCA of paroxysmal AF using either HFLTV+RAP (500-600 msec) or HFLTV ventilation alone from April 2020 to February 2023 were included. The primary outcome was freedom from all-atrial arrhythmias at 12-month follow-up. Secondary outcomes included procedural characteristics, long-term clinical outcomes, and procedure-related complications. Results: A total of 545 patients were included in the analysis (HFLTV+RAP=327 vs. HFLTV=218). There were no significant differences in baseline characteristics between the groups. No differences were observed in procedural (HFLTV+RAP 74 [57-98] vs. HFLTV 66 [53-85.75] min, p=0.617) and RF (HFLTV+RAP 15.15 [11.22-21.22] vs. HFLTV 13.99 [11.04-17.13] min, p=0.620) times. Both groups showed a similar freedom from all-atrial arrhythmias at 12-month follow-up (HFLTV+RAP 82.68% vs. HFLTV 86.52%, HR=1.43, 95% CI [0.94-2.16], p=0.093). There were no significant differences in freedom from AF-related symptoms (HFLTV+RAP 91.4% vs. HFLTV 93.1%, p=0.476) or AF-related hospitalizations (HFLTV+RAP 98.5% vs. HFLTV 97.2%, p=0.320). Procedure-related complications were low in both groups (HFLTV+RAP 0.6% vs. HFLTV 0%, p=0.247). Conclusion: In patients undergoing RFCA for paroxysmal AF, adding RAP to HFLTV-ventilation was not associated with improved procedural and long-term clinical outcomes.

Lamin Cardiomyopathy (LC) is associated with refractory ventricular arrhythmias. Catheter ablation success rate is low due to presence of multiple circuits and intramural substrate. We present a LC case presented with electrical storm. During catheter ablation, arrhythmia was easily inducible but activation mapping, including full epicardial and endocardial mapping, failed to demonstrate the full tachycardia cycle length (70% only) suggesting intramural activation. Critical isthmus was not identified even with successful concealed entrainment on both Endo/epicardial surfaces. This case shows that even combined endocardial and epicardial catheter approach can be ineffective in identifying the full arrhythmogenic substrate in LC.

Background: Ventricular tachycardia (VT) remains a leading cause of morbidity and sudden death. Improvements in catheter ablation have significantly advanced this option as a treatment method for refractory VT. Despite advances, use and impact of inotrope and vasodepressor medicines as part of intraprodcedural management during VT ablation have been understudied. Methods: We conducted a exploratory, retrospective analysis of consecutive patients undergoing VT ablation. Patient, intra and peri-procedural data, focusing on pressor use and hemodynamics through ablation, and procedural endpoint data were collected. Results: From 2014-2017, 149 patients underwent VT ablation of which 67% exhibited cardiomyopathy (53% ischemic). Most procedures (71%) were conducted under general anesthesia. In those with cardiomyopathy, steady-state use of dobutamine and dopamine was more common though substantial use of phenylephrine was noted. In adjusted analyses, (1) dobutamine was associated with increased procedure time (402.5±18.8 vs 347.2±14.0 min, p = 0.03), (2) dopamine was associated with increased number of distinct VTs (2.8 vs. 2.2, p<0.001) while both dopamine and dobutamined resulted in increased intra-procedural cardioversions (1.3 vs. 0.6, p<0.001 and 1.34 vs. 0.66, p=0.001, respectively) and (3) dobutamine dose exhibited a linear correlation with post-ablation length of stay. Conclusions: In this exploratory work, we sought to understand effects of hemodynamic drug use on short-term, procedural outcomes of VT ablation. Salient findings include: (1) arrhythmogenic nature of inotropes resulting in an increase in intraprocedural cardioversions, (2) greater propensity for induction of non-clinical VTs with use of intraprocedural dopamine and (3) substantial use of phenylephrine in those with underlying cardiomyopathy.