Visualization and mapping of the right phrenic nerve by intracardiac echocardiography during atrial fibrillation ablation

Abstract

Objective This study aimed to evaluate the feasibility of real-time visualization and mapping of the right phrenic nerve (RPN) by using intracardiac echocardiography (ICE) during atrial fibrillation (AF) ablation. Background RPN injury is a complication associated with the ablation of AF. Multiple approaches are currently being used to prevent and detect RPN injuries. However, none of these approaches can directly visualize the RPN in real-time during the ablation procedure. Methods and results The RPN was detected using ICE. The RPN and its adjacent structures were analysed. The relationship between the RPN’s distance from the superior vena cava (SVC) and its pacing capture threshold was quantified. The safety of SVC isolation guided by the ICE-visualized RPN was evaluated. Thirty-eight people were enrolled in this study. The RPN was visualized by ICE in 92% of patients. It ran through the space between the SVC and the mediastinal pleura and had a ‘straw’-like appearance upon ICE imaging. The course of the RPN was close to the SVC (minimum 1.0 ± 0.4 mm) and the right superior pulmonary vein (minimum 14.1 ± 7.3 mm). There was a positive linear correlation between the RPN’s capture threshold and its distance from the SVC (Spearman’s correlation coefficient = 0.728, < 0.001). SVC isolation was guided by the RPN; none of the patients developed an RPN injury. Conclusions RPN can be visualized by ICE in most patients, thus providing a novel approach for the real-time detection of RPN during AF ablation.

Impact of intracardiac echocardiography usage on the safety of cryoballoon atrial fibrillation ablation: Subanalysis of the prospective FREEZE cluster cohort study

“…In the ICE group, phrenic nerve pacing with palpation of the diaphragmatic contraction was performed more frequently as compared to the non‐ICE group (97.3% vs. 90.5%, p < .001). Furthermore, ICE can be used to visualized the diaphragmatic movement during stimulation of the phrenic nerve, 12 and to visualize the right phrenic nerve and its anatomical relationship to the PV during AF ablation 29 . More research is necessary to clarify if the differences in transient PNP rates are of causally related to ICE usage in CBA.…”

Proposal for Manual Osteopathic Treatment of the Phrenic Nerve

“…The pericardium (and some myocardial fibers) merges with a small portion of the superior and inferior vena cava (above and below the diaphragm); the pericardial/myocardial fibers appear to be innervated by the right phrenic nerve, which has catecholaminergic characteristics [ 44 , 45 ].…”

Echocardiography derived total atrial conduction time: guidance in management of atrial fibrillation

“…AF is associated with a higher cardiovascular morbidity and mortality, and timely identification of AF may help to avoid complications and improve outcome. There is a considerable amount of data demonstrating the value of PA-TDI duration to predict the development of newonset AF (16).…”