How Close Are the Phrenic Nerves to Cardiac Structures? Implications for Cardiac Interventionalists

Kuwahara

2009

Circ J

Circ J 2009; 73: 221 -226 ince the discovery of the main role of pulmonary vein (PV) foci in the initiation of atrial fibrillation (AF), 1 radiofrequency (RF) catheter ablation, basically targeting the PVs, has been developed as an effective treatment for recurrent, drug-resistant AF. [2][3][4] Moreover, various types of ablation strategies, such as extensive circumferential PV isolation including the atrial tissue in the adjacent left atrium (LA), 5-12 linear ablation [13][14][15][16] and complex fractionated electrogram-guided ablation, [17][18][19][20][21] have been used to achieve a high efficacy for all types of AF. However, these extensive and complex ablation strategies are associated with a relatively higher incidence of complications, 22,23 compared with ablation of other arrhythmias. Moreover, devastating complications, such as atrio-esophageal fistulas, have been reported, 24,25 caused by extracardiac penetration of the ablative energy, which is 1 of the unsolved safety issues concerning AF ablation. Incidence of ComplicationsComplications of AF ablation include vascular access accidents, cardiac perforation/tamponade, thromboembolic events, PV stenosis, extracardiac injury such as to the esophagus, nerve damage, and atypical atrial flutter. In a worldwide survey of 8,745 patients who underwent AF ablation reported by Cappato et al, 22 major complications occurred in 524 patients (6%), including 4 periprocedural deaths (0.05%) from massive cerebral thromboembolism in 2, extrapericardial PV perforation in 1, and an unknown cause in 1 patient. The incidence of cardiac tamponade was 1.2%, and significant PV stenosis >50%, stroke and atypical atrial flutter of new onset occurred in 1.31%, 0.28% and 3.7% of the patients, respectively. A large, prospective, multicenter Italian investigation of ablation-related complications recently reported that in 1,011 AF patients complications occurred in 40 (3.9%): 4 (0.4%) had a stroke, 6 (0.6%) had cardiac tamponade, and 4 (0.4%) had significant PV stenosis >50%. 23 Among our 1,600 patients who underwent extensive encircling isolation of both of the ipsilateral PVs guided by fluoroscopy between 2003 and 2008, overall complications occurred in 23 patients (1.4%): 4 (0.25%) had stroke, 10 (0.6%) had cardiac tamponade, 3 (0.19%) had damage to the peri-esophageal vagal plexus and 6 (0.38%) had transient phrenic nerve (PN) injury; however, there were no cases of significant PV stenosis >50% or atrio-esophageal fistula.Predictors of complications in AF ablation have been reported by some investigators, such as coronary disease, 23 advanced age, 26,27 and female gender. 27 Spragg et al found that the complication rates were higher during the first 100 cases (9%) than during the subsequent 541 cases (4.3%), indicating the salutary effect of institutional or individual operator experience. 27 ThromboembolismThe incidence of thromboembolism caused by AF ablation is 0.28-2.8%. 9,13,22,23,28-32 A worldwide survey reported periprocedural deaths because of massive cerebral thr...

Section: Pn Injurymentioning

confidence: 89%

Complications in the Catheter Ablation of Atrial Fibrillation

Kuwahara

2009

Circ J

Southwest J Pulm Crit Care

“…It is thought that the phrenic nerve gets injured due to the close anatomic relationship of the phrenic nerve to the heart (Figure 3). Both the right and the left phrenic nerves can get damaged -the right phrenic nerve is specifically at risk when ablations are carried out in the superior caval vein and the right superior pulmonary vein, and the left phrenic nerve is liable to damage during lead implantation into the great cardiac and left obtuse marginal veins (8). In our patient, the right phrenic nerve, which runs along the lateral surfaces of the superior vena cava and right atrium, was injured by energy delivered to the adjacent area during ablation.…”

Section: Discussionmentioning

confidence: 99%

Phrenic nerve injury post catheter ablation for atrial fibrillation

Sen¹,

Majumdar²,

Saeed³

2018

Objective: Phrenic nerve injury (PNI) is a complication of catheter ablation treatment of atrial fibrillation (AF). This condition can mimic that of comorbid conditions like congestive heart failure (CHF) and chronic obstructive pulmonary disease (COPD). Case details: A 77-year-old woman with past medical history of heart failure with preserved ejection fraction and mild COPD, presented with dyspnea for 8 days. One week ago, she had undergone radiofrequency catheter ablation for persistent symptomatic AF. After the ablation, she reported dyspnea during PCP and pulmonary office visits and was given increasing doses of diuretics and inhalers since her symptoms were attributed to acute exacerbation of heart failure in the setting of COPD. However, a chest x-ray showed elevation of the right hemidiaphragm, and she had a positive sniff test. She was thus diagnosed with right sided phrenic nerve palsy and was treated with oxygen therapy.

J Innov Cardiac Rhythm Manage

“…Finally, the left phrenic nerve can, along its course, come close to the CGV, so capture of the phrenic nerve by highoutput pacing inside the GCV can likewise prohibit safe ablation in that site. 7 For all of the above reasons, it is not surprising that the reported rate of acute success with ablation of GCV/AIV PVCs is 43% to 70% only. 4,8,9 For the same reasons, it is important to have alternative strategies for ablating such PVCs.…”

Section: Discussionmentioning

confidence: 99%

Successful Ablation of Epicardial Premature Ventricular Complexes Near the Great Cardiac Vein from the Left Ventricular Endocardium Despite Predictors of Failure

Kumar

Jessel

Raitt

et al. 2017

ABSTRACT. Mapping and ablating premature ventricular complexes (PVCs) that originate near the great cardiac vein (GCV) and anterior interventricular vein (AIV) can pose several challenges related to the advancement and positioning of catheters within these veins, the delivery of effective lesions, and the risk of collateral injury to the left coronary arteries and left phrenic nerve. When ablation of these PVCs from inside the GCV/AIV is not possible, a systematic assessment of nearby vantage points, such as the left coronary cusp (LCC) and left ventricular (LV) endocardial breakout site, should be considered, in addition to the performance of a more invasive epicardial ablation procedure via a percutaneous pericardial puncture or thoracotomy. Several electrocardiographic, anatomic, and electrogram timing features have been shown to predict the likelihood of successful ablation from a non-epicardial site, such as the LCC or LV endocardium, but none of these spots is considered to be a perfect location. The case described here in this report is a demonstration of a safe and successful ablation of GCV PVCs from the LV endocardial breakout site using adequate power and lesion duration, even when the site was 17 mm away from the putative origin, and some previously described electrocardiographic and electrogram-based predictors of success suggested the outcome would not be positive.