Physiologic lead placement with electroanatomic mapping: A case series.

INTRODUCTION: His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) have emerged as attractive alternatives to traditional biventricular pacing to achieve cardiac resynchronization therapy. Early reported results have been inconsistent, particularly amongst patients in whom initial placement with traditional approaches has been unsuccessful or those with complex anatomy or congenital abnormalities. In this report, we describe the use of three-dimensional electroanatomic mapping (EAM) in five selected cases. METHODS: Five patients from multiple clinical sites underwent EAM-guided HBP or LBBAP by highly trained electrophysiologists with significant experience with conduction system pacing. Each patient in this series underwent EAM-guided conduction system pacing due to complex anatomy and/or prior failed lead implantation. RESULTS: EAM-guided lead implantation was successful in all five cases. Capture thresholds were relatively low and patients continued to have evidence of successful lead implantation with minimum 1-month follow-up. The fluoroscopy time varied, likely owing to the variable complexity of the cases. CONCLUSIONS: The use of EAM, in combination with traditional intracardiac electrograms with or without fluoroscopy, allows more targeted and precise placement of leads for HBP and LBBAP pacing. Further investigation is needed to determine this strategy's long-term performance and to optimize patient selection.

Repeat pulmonary vein isolation with or without FIRM-guided ablation for recurrent atrial fibrillation with pulmonary vein reconnection.

INTRODUCTION: Focal impulse and rotor modulation (FIRM) ablation can be used to target nonpulmonary vein (PV) sources of atrial fibrillation (AF). No published studies have compared freedom from atrial fibrillation (FFAF) after pulmonary vein reisolation (PVRI) plus FIRM to PVRI alone in patients with reconnected PVs undergoing repeat ablation. METHODS: A 3:1 matched retrospective cohort study was performed on 21 patients with recurrent AF and PV reconnection who underwent PVRI plus FIRM-guided ablation and 63 patients with recurrent AF treated with PVRI alone at a single institution. All patients in the PVRI-alone cohort had cryoballoon PVRI at the time of repeat ablation without additional lesion sets for AF. Cases were matched based on the type of AF (paroxysmal vs nonparoxysmal), left atrial diameter (±4 mm), left ventricular ejection fraction (±10%), duration of AF (±18 months), and age (±5 years). The primary endpoint was FFAF after a 3-month blanking period. RESULTS: Out of 53 total FIRM cases performed at Northwestern Memorial Hospital between 2015 and 2017, 21 patients had PVRI plus FIRM for recurrent AF with PV reconnection. These patients had an average of 3.3 ± 2.1 rotors (60% left atrial) ablated. Over a median follow-up time of 24.7 months (interquartile range, 13-36 months), patients in the PVRI-alone cohort demonstrated a higher rate of FFAF (n = 35; 55.6%) than patients in the PVRI plus FIRM-guided ablation cohort (n = 7; 33.3%) (logrank P = .049). CONCLUSION: In patients undergoing repeat ablation for AF with PV reconnection, PVRI plus FIRM did not increase FFAF compared to PVRI alone.

Characterization of atrial flutter after pulmonary vein isolation by cryoballoon ablation.

PURPOSE: Pulmonary vein isolation (PVI) by cryoballoon ablation (CBA) has emerged as a commonly used technique for the treatment of atrial fibrillation. We sought to explore the incidence, risk factors for, and characterization of post-CBA-PVI atrial flutter. METHODS: We analyzed a prospective registry of patients who underwent CBA-PVI at a single institution. We included patients with more than 3 months of follow-up data and excluded those with a history of cavotricuspid isthmus (CTI) ablation. Locations of post-CBA-PVI atrial flutters were determined by analysis of intracardiac electrograms and electroanatomic maps. RESULTS: There were 556 patients included in the analysis. The mean age was 61.0 ± 10.6 years, 67.4% were male, the number of failed anti-arrhythmic medication trials was 1.2 ± 0.8, and the duration of atrial fibrillation pre-CBA was 54.3 ± 69.1 months. The 28-mm second-generation cryoballoon was used almost exclusively. Over a median follow-up time of 22.7 ± 17.9 months, 25 (4.5%) patients developed post-CBA-PVI atrial flutter after the 3-month blanking period. Of those 25 patients, 15 (60%) underwent subsequent ablation to eliminate the atrial flutter circuit, with 60% being CTI-dependent and the remainder left-sided (p value not significant). Risk factors for the development of atrial flutter included NYHA class ≥ 2 (OR 5.02, p < 0.001), presence of baseline bundle branch block (OR 4.33, p = 0.006), and left ventricular ejection fraction < 50% (OR 3.36, p = 0.007). CONCLUSIONS: The rate of post-CBA-PVI atrial flutter is low after the blanking period even with medium-term follow-up. The origin of atrial flutter is equally divided between the right and left atria.

Use of the cryoballoon to ablate pulmonary vein-dependent left atrial flutter.

New atrial flutter (AFL) that arises after pulmonary vein isolation (PVI) by catheter or surgical ablation can originate from reconnection of a pulmonary vein (PV). Reisolation of PVs with cryoballoon ablation (CBA) for treatment of peri-PV AFL after Maze or PVI has not previously been reported. The present case series describes use of CBA to treat post-PVI and post-Maze PV-dependent AFL. In these cases, CBA was used to reisolate the PVs and terminate AFL without requiring additional lesion sets for treatment of AFL.