Phrenic Nerve Injury: An Underrecognized and Potentially Preventable Complication of Pulmonary Vein Isolation Using a Wide‐Area Circumferential Ablation Approach

Abstract

High output pacing around the right pulmonary veins and the carina reveals that the phrenic nerve lies along a wide-area circumferential ablation trajectory in 30% of patients. Modification of ablation lines to avoid these sites may prevent phrenic nerve injury during RF PVI.

2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-up, Definitions, Endpoints, and Research Trial Design

“…These include limiting ablation to antral regions with various balloon maneuvers; preablation high-output pacing to establish whether the PN can be captured from the proposed ablation site before ablation; PN mapping with anatomic tagging of its course using an EAM system to guide the modification of the ablation lesion set; and monitoring of diaphragmatic excursion with abdominal palpation, fluoroscopy, or intracardiac ultrasound while pacing the PN from the SVC or subclavian vein during ablation. 1196 Monitoring the effects of pacing the right PN is now considered a standard part of CBA and should be considered during SVC isolation using RF energy. Of the writing group members, 96% report employing this technique when performing CB AF ablation.…”

Novel Technique to Prevent Phrenic Nerve Injury During Pulmonary Vein Isolation Using Preprocedural Imaging

“…Testing for PN capture was performed with high energy stimulation (20 mA at 2 ms pulse duration), with the ablation catheter along the anterior border of the right PVs (Fig. A,B).…”

“…It is more likely to occur with cryoballoon PVI than with radiofrequency (RF) energy. Recent studies demonstrated that PN injury can occur even when wide area circumferential ablation (WACA) approach is used . One possible explanation is the lack of an objective definition of WACA.…”

“…High output pacing in the region targeted for ablation allows the identification of the location of the PN. Avoiding ablation in these regions can prevent PN injury . Although this approach may decrease the risk of PN injury during RF ablation, pacing in multiple locations can result in prolongation of the procedural time and interruption of ablation if a dragging ablation approach is used.…”

Epicardial Phrenic Nerve Displacement During Catheter Ablation of Atrial and Ventricular Arrhythmias

“…1,6 Furthermore, PN injury may persist in ≤33% of patients in long-term follow-up causing significant morbidity. 1,6 Several techniques for avoiding PN injury have been reported, including pace mapping to identify sites close to the PN to avoid ablation, 4,14 use of lower power settings (10 watts in one study), 15 and PN displacement using an epicardially placed balloon, sheath/catheter combination, and pericardial injection of saline, air, or both. 2,11,[16][17][18][19][20] The experience with PN displacement techniques is limited to animal studies, 19 isolated case reports, 2,11,16 or small series of patients.…”