Prospective Evaluation of Electromyography‐Guided Phrenic Nerve Monitoring During Superior Vena Cava Isolation to Anticipate Phrenic Nerve Injury

Abstract

Stable right diaphragmatic CMAPs could be obtained, and monitoring CMAPs might be useful for anticipating right PNI during SVC isolation.

Phrenic nerve injury post catheter ablation for atrial fibrillation

“…In 2014, Linhart et al (12) performed studies to show that fluoroscopic assessment of diaphragm movement during spontaneous breathing was more sensitive for the diagnosis of phrenic nerve injury as compared to SVC pacing (12). It has also been seen that EMG-guided approach results in less damage to the phrenic nerve and a significant reduction in hemi-diaphragmatic paralysis as compared to current methods of abdominal palpation and fluoroscopy (13).…”

Electrical superior vena cava isolation using a novel pace-and-ablate technique under diaphragmatic electromyography monitoring

“…[10][11][12] We have recently reported the potential use of diaphragmatic CMAP monitoring to prevent right PNI during electrical SVC isolation. 13 However, in this technique, an additional pacing catheter is required with a stable placement in the right subclavian vein throughout the procedure, and phrenic nerve capture needs to be evaluated before each radiofrequency (RF) application by high output pacing from the tip of the ablation/mapping catheter. In the present study, we assessed the feasibility of a novel SVC isolation technique using simultaneous pacing and ablation through the tip of a single mapping/ablation catheter with CMAP monitoring to simplify these issues.…”

The Role of Superior Vena Cava Isolation in the Management of Atrial Fibrillation

“…Using this technique, Miyazaki et al successfully performed RFA at sites of phrenic nerve capture without phrenic nerve injury in 98.6% of radiofrequency (RF) applications. 27 In one application (1.4%), RF application was interrupted due to a decrease in CMAP amplitude, without evidence of phrenic nerve injury, and subsequent recovery of CMAP amplitude. 27 SVC stenosis is another common concern with SVCI, but clinically significant stenosis is quite rare.…”

“…27 In one application (1.4%), RF application was interrupted due to a decrease in CMAP amplitude, without evidence of phrenic nerve injury, and subsequent recovery of CMAP amplitude. 27 SVC stenosis is another common concern with SVCI, but clinically significant stenosis is quite rare. Fenelon et al raised awareness of this potential complication by demonstrating that RFA in canine caval veins was associated with luminal narrowing in 100% of the cases examined, and was moderate or severe in 50%.…”

“…Monitoring right diaphragmatic compound motor action potentials (CMAPs), as is used with cryoballoon ablation, can be used to anticipate and prevent phrenic nerve injury, even with phrenic nerve capture. 27 At SVC sites where the phrenic nerve is captured with high-output pacing, radiofrequency ablation (RFA) can be delivered while pacing the right phrenic nerve from the right subclavian vein. Ablation should be terminated immediately, however, if there is a reduction in strength of diaphragmatic contraction, or a 430% reduction of the maximum baseline CMAP amplitude.…”