Factors associated with periesophageal vagal nerve injury after pulmonary vein antrum isolation

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

Characteristics of radiofrequency lesions in patients with symptomatic periesophageal vagal nerve injury after pulmonary vein isolation

Background

Periesophageal vagal nerve injury (PNI) is an unpredictable and serious complication of atrial fibrillation (AF) ablation. We aimed to identify the factors associated with symptomatic PNI.

Methods

This study included 1391 patients who underwent ablation index-guided pulmonary vein isolation (PVI) using the CARTO system. The target ablation index was set at 550, except for the left atrial (LA) posterior wall near the esophagus, where radiofrequency (RF) power and duration were limited. Ten patients (0.72%) were diagnosed with symptomatic PNI. We randomly selected 40 patients without PNI (1:4 ratio) matched based on age, sex, body mass index, LA diameter, type of AF, and esophageal location. We measured the shortest distance from the RF lesions to the esophagus (LED) and classified the RF lesions according to the LED into four groups: 0-5, 5-10, 10-15, and 15-20 mm. We conducted a comparative analysis of classified RF lesions between patients with PNI (n = 10) and those without (n = 40).

Results

The contact force at LED 0-5 mm was significantly higher in patients with PNI than in those without (14.6 ± 1.7 vs. 12.0 ± 2.9 g; p = .01). Multivariate logistic analysis revealed that the independent factor for PNI was contact force at an LED of 0-5 mm (odds ratio: 1.506; 95% confidence interval: 1.053-2.153; p = .025).

Conclusions

The symptomatic PNI was significantly associated with a higher contact force near the esophagus. Strategies for regulating contact force near the esophagus may aid in the prevention of PNI.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Characteristics of tissue temperature during ablation with THERMOCOOL SMARTTOUCH SF versus TactiCath versus QDOT MICRO catheters (Qmode and Qmode+): An in vivo porcine study

INTRODUCTION

High-power short-duration (HPSD) ablation at 50 W, guided by ablation index (AI) or lesion size index (LSI), and a 90 W/4 s very HSPD (vHPSD) setting are available for atrial fibrillation (AF) treatment. Yet, tissue temperatures during ablation with different catheters around venoatrial junction and collateral tissues remain unclear.

METHODS

In this porcine study, we surgically implanted thermocouples on the epicardium near the superior vena cava (SVC), right pulmonary vein, and esophagus close to the inferior vena cava. We then compared tissue temperatures during 50W-HPSD guided by AI 400 or LSI 5.0, and 90 W/4 s-vHPSD ablation using THERMOCOOL SMARTTOUCH SF (STSF), TactiCath ablation catheter, sensor enabled (TacthCath), and QDOT MICRO (Qmode and Qmode+ settings) catheters.

RESULTS

STSF produced the highest maximum tissue temperature (Tmax ), followed by TactiCath, and QDOT MICRO in Qmode and Qmode+ (62.7 ± 12.5°C, 58.0 ± 10.1°C, 50.0 ± 12.1°C, and 49.2 ± 8.4°C, respectively; p = .005), achieving effective transmural lesions. Time to lethal tissue temperature ≥50°C (t-T ≥ 50°C) was fastest in Qmode+, followed by TacthCath, STSF, and Qmode (4.3 ± 2.5, 6.4 ± 1.9, 7.1 ± 2.8, and 7.7 ± 3.1 s, respectively; p < .001). The catheter tip-to-thermocouple distance for lethal temperature (indicating lesion depth) from receiver operating characteristic curve analysis was deepest in STSF at 5.2 mm, followed by Qmode at 4.3 mm, Qmode+ at 3.1 mm, and TactiCath at 2.8 mm. Ablation at the SVC near the phrenic nerve led to sudden injury at t-T ≥ 50°C in all four settings. The esophageal adventitia injury was least deep with Qmode+ ablation (0.4 ± 0.1 vs. 0.8 ± 0.4 mm for Qmode, 0.9 ± 0.3 mm for TactiCath, and 1.1 ± 0.5 mm for STSF, respectively; p = .005), correlating with Tmax .

CONCLUSION

This study revealed distinct tissue temperature patterns during HSPD and vHPSD ablations with the three catheters, affecting lesion effectiveness and collateral damage based on Tmax and/or t-T ≥ 50°C. These findings provide key insights into the safety and efficacy of AF ablation with these four settings.

Symptomatic periesophageal vagal nerve injury by different energy sources during atrial fibrillation ablation

Background

Symptomatic gastric hypomotility (SGH) is a rare but major complication of atrial fibrillation (AF) ablation, but data on this are scarce.

Objective

We compared the clinical course of SGH occurring with different energy sources.

Methods

This multicenter study retrospectively collected the characteristics and clinical outcomes of patients with SGH after AF ablation.

Results

The data of 93 patients (67.0 ± 11.2 years, 68 men, 52 paroxysmal AF) with SGH after AF ablation were collected from 23 cardiovascular centers. Left atrial (LA) ablation sets included pulmonary vein isolation (PVI) alone, a PVI plus a roof-line, and an LA posterior wall isolation in 42 (45.2%), 11 (11.8%), and 40 (43.0%) patients, respectively. LA ablation was performed by radiofrequency ablation, cryoballoon ablation, or both in 38 (40.8%), 38 (40.8%), and 17 (18.3%) patients, respectively. SGH diagnoses were confirmed at 2 (1-4) days post-procedure, and 28 (30.1%) patients required re-hospitalizations. Fasting was required in 81 (92.0%) patients for 4 (2.5-5) days; the total hospitalization duration was 11 [7-19.8] days. After conservative treatment, symptoms disappeared in 22.3% of patients at 1 month, 48.9% at 2 months, 57.6% at 3 months, 84.6% at 6 months, and 89.7% at 12 months, however, one patient required surgery after radiofrequency ablation. Symptoms persisted for >1-year post-procedure in 7 patients. The outcomes were similar regardless of the energy source and LA lesion set.

Conclusions

The clinical course of SGH was similar regardless of the energy source. The diagnosis was often delayed, and most recovered within 6 months, yet could persist for over 1 year in 10%.

Pulmonary vein isolation-induced vagal nerve injury and gastric motility disorders detected by electrogastrography: The side effects of pulmonary vein isolation in atrial fibrillation (SEPIA) study

INTRODUCTION

Safety of pulmonary vein isolation (PVI) has been established in clinical studies. However, despite prevention efforts the incidence of damage to (peri)-esophageal tissue has not decreased, and the pathophysiology is incompletely understood. Damage to vagal nerve branches may be involved in lesion progression to atrio-esophageal fistula. Using electrogastrography, we assessed the incidence of periesophageal vagal nerve injury (VNI) following atrial fibrillation ablation and its association with procedural parameters and endoscopic results.

METHODS

Patients were studied using electrogastrography, endoscopy, and endoscopic ultrasound before and after cryoballoon (CB) or radiofrequency (RF) PVI. The incidence of ablation-induced neuropathic pattern (indicating VNI) in pre- and postprocedural electrogastrography was assessed and correlated with endoscopic results and ablation data.

RESULTS

Between February 2021 und January 2022, 85 patients (67 ± 10 years, 53% male) were included, 33 were treated with CB and 52 with RF (38 with moderate power moderate duration [25-30 W] and 14 with high power short duration [50 W]). Ablation-induced VNI was detected in 27/85 patients independent of the energy form. Patients with VNI more frequently had postprocedural endoscopically detected pathology (8% mucosal esophageal lesions, 36% periesophageal edema, 33% food retention) but there was incomplete overlap. Pre-existing esophagitis increased the likelihood of VNI. Ablation data and esophageal temperature data did not predict VNI.

CONCLUSION

PVI-induced VNI is quite common and independent of ablation energy source. VNI is part of (peri)-esophageal damage and only partially overlaps with endoscopic findings. VNI-associated acidic reflux may be involved in the complex pathophysiology of esophageal lesion progression to fistula.

DR-FLASH Score Is Useful for Identifying Patients With Persistent Atrial Fibrillation Who Require Extensive Catheter Ablation Procedures

Background

Modification of arrhythmogenic substrates with extensive ablation comprising linear and/or complex fractional atrial electrogram ablation in addition to pulmonary vein isolation (PVI‐plus) can theoretically reduce the recurrence of atrial fibrillation. The DR‐FLASH score (score based on diabetes mellitus, renal dysfunction, persistent form of atrial fibrillation, left atrialdiameter >45 mm, age >65 years, female sex, and hypertension) is reportedly useful for identifying patients with arrhythmogenic substrates. We hypothesized that, in patients with persistent atrial fibrillation, the DR‐FLASH score can be used to classify patients into those who require PVI‐plus and those for whom a PVI‐only strategy is sufficient.

Methods and Results

This study is a post hoc subanalysis of the a multicenter, randomized controlled, noninferiority trial investigating efficacy and safety of pulmonary vein isolation alone for recurrence prevention compared with extensive ablation in patients with persistent atrial fibrillation (EARNEST‐PVI trial). This analysis focuses on the relationship between DR‐FLASH score and the efficacy of different ablation strategies. We divided the population into 2 groups based on a DR‐FLASH score of 3 points. A total of 469 patients were analyzed. Among those with a DR‐FLASH score >3 (N=279), the event rate of atrial arrhythmia recurrence was significantly lower in the PVI‐plus arm than in the PVI‐only arm (hazard ratio [HR], 0.45 [95% CI, 0.28–0.72]; P<0.001). In contrast, among patients with a DR‐FLASH score ≤3 (N=217), no differences were observed in the event rate of atrial arrhythmia recurrence between the PVI‐only arm and the PVI‐plus arm (HR, 1.08 [95% CI, 0.61–1.89]; P=0.795). There was significant interaction between patients with a DR‐FLASH score >3 and DR‐FLASH score ≤3 (P value for interaction=0.020).

Conclusions

The DR‐FLASH score is a useful tool for deciding the catheter ablation strategy for patients with persistent atrial fibrillation.

Registration

URL: https://clinicaltrials.gov; Unique identifier: NCT03514693.

Protecting Against Collateral Damage to Non-cardiac Structures During Endocardial Ablation for Persistent Atrial Fibrillation

Injury to structures adjacent to the heart, particularly oesophageal injury, accounts for a large proportion of fatal and life-altering complications of ablation for persistent AF. Avoiding these complications dictates many aspects of the way ablation is performed. Because avoidance involves limiting energy delivery in areas of interest, fear of extracardiac injury can impede the ability of the operator to perform an effective procedure. New techniques are becoming available that may permit the operator to circumvent this dilemma and deliver effective ablation with less risk to adjacent structures. The authors review all methods available to avoid injury to extracardiac structures to put these developments in context.

Severe sphincter of Oddi spasm after cryoballoon ablation: a case report of an unusual complication after atrial fibrillation ablation

Background 

Perioesophageal vagal nerve (VN) injury after atrial fibrillation (AF) ablation remains an important complication. The VN provides parasympathetic innervation to the majority of the abdominal organs—including the stomach and the sphincter of Oddi (SO)—and regulates smooth muscle contraction. We present an unusual case of SO spasm induced by VN injury after cryoballoon ablation (CBA).

Case summary 

A 71-year-old woman presented to our institution with paroxysmal AF. The patient had a history of cholecystectomy and SO dysfunction. She had undergone CBA for AF. Immediately after the procedure, the patient developed epigastric pain. Computed tomography showed dilation of the intra- and extrahepatic bile ducts, with the diameter of the common bile duct measuring ∼15.6 mm. Blood tests on postoperative Day 1 revealed severely elevated aminotransferase levels (aspartate aminotransferase, 3156 U/L; alanine aminotransferase, 2084 U/L; lactate dehydrogenase, 2279 U/L; total bilirubin 1.7 mg/dL).

Discussion 

It is known that VN denervation induces SO spasms. The right and left vagal trunks descend alongside the oesophagus, forming a perioesophageal plexus and innervating most of the gastrointestinal organs. In our case, SO spasm was induced as a result of the perioesophageal plexus injury caused by CBA. Underlying SO dysfunction and post-cholecystectomy also played an important role. Coupled with the absence of the gallbladder, which is the reservoir of bile juice and coordinator of SO, SO spasm caused severe elevation of the bile duct pressure. Care should be taken when performing AF ablation with regards to the stomach and the SO.

Anatomical evaluation of the esophagus using computed tomography to predict acute gastroparesis following atrial fibrillation ablation

BACKGROUND

Catheter ablation for atrial fibrillation is an effective treatment; however, periesophageal vagal nerve injury is not rare and sometimes results in acute gastroparesis (AGP) after atrial fibrillation ablation (AFA). We sought to investigate the incidence and risk factors of AGP via preprocedural computed tomography (CT) analysis.

METHODS

We retrospectively reviewed 422 patients who underwent index AFA at our center. Using contrast-enhanced CT performed before ablation, the anatomical characteristics of the esophagus were compared between patients with and without post-ablation AGP. AGP was diagnosed by the presence of symptoms, fasting abdominal X-ray radiography as a screening test, and additional abdominal imaging.

RESULTS

Of the 422 patients (age, 67 ± 11 years; male, 68.5%; cryoballoon, 63.7%), AGP developed in 14 (3.3%) patients, and six of 14 patients were asymptomatic. AGP resolved in all patients within 4 weeks without invasive treatment. In the AGP group, the esophagus was frequently located on the vertebra (middle-positioned esophagus) (AGP vs non-AGP, 42.9% vs 11.5%; P = .01), and additional posterior wall ablation was frequently performed (50.0% vs 14.5%; P = .02). In the multivariate analysis, middle-positioned esophagus (P = .02; odds ratio, 9.0; 95% confidence interval [CI], 1.5-53.3) and additional posterior wall ablation (P = .01; odds ratio, 7.6; 95% CI, 1.5-42.1) were independent predictors of AGP.

CONCLUSIONS

Anatomical evaluation of the esophagus using CT may be simple and useful for predicting AGP after AFA. High-risk patients who have middle-positioned esophagus or who underwent excessive posterior wall ablation should be followed up closely.

Local impedance-guided radiofrequency ablation with standard and high power: Results of a preclinical investigation

BACKGROUND

Local impedance (LI) drop measured with microfidelity electrodes embedded in the tip of an ablation catheter accurately reflects tissue heating during radiofrequency (RF) ablation. Previous studies found 15-30 Ω LI drops created successful lesions, while more than 40 Ω drops were associated with steam pops. The objective of this study was to evaluate the safety and efficacy of LI-guided ablation using standard (30 W) and high-power (50 W) in a preclinical model.

METHODS

RF lesions were created in explanted swine hearts (n = 6) to assess the feasibility of LI-guided ablation by targeting 10, 20, or 30 Ω (n = 20/group) drops. Subsequently, LI-guided ablation was evaluated in a chronic animal model (n = 8 Canines, 25-29 kg, 30/50 W). During the index procedure point-by-point intercaval line ablation and left inferior pulmonary vein (PV) isolation were performed. RF duration was at the operators' discretion but discontinued early if a 15-30 Ω drop was achieved. Operators attempted to avoid LI drops of more than 40 Ω. At 1-month, durable conduction block was evaluated with electroanatomic mapping followed by necropsy and histopathology.

RESULTS

In explanted tissue, terminating ablation at 10, 20, or 30 Ω LI drops created statistically larger lesions (p < .05; 1.8 [1.6-2.4] mm, 3.3 [3.0-3.7] mm; 4.9 [4.3-5.5] mm). LI-guided high-power ablation in vivo significantly reduced RF duration per application compared to standard-power (p < .05; intercaval: 8.9 ± 5.2 vs. 18.1 ± 11.0 s, PV: 9.6 ± 5.4 vs. 23.2 ± 10.3 s). LI drops of 15-40 Ω were more readily achievable for high-power (90.1%, 318/353) than standard-power (71.7%, 243/339). All intercaval lines and PV isolations were durable (16/16) at 1-month. Necropsy revealed no major collateral injury to the pericardium, phrenic nerve, esophagus, or lungs. There was no pericardial effusion, stroke, tamponade, or PV stenosis. Vagal nerve injury was found in two 30 W animals after using 19.7 ± 13.9 and 19.5 ± 11.8 s RF applications.

CONCLUSION

LI-guided ablation was found to be safe and efficacious in a chronic animal model. High-power ablation more readily achieved more than 15 Ω drops, reduced RF duration compared with standard-power, and had no major RF collateral injury.

High incidence of (ultra)low oesophageal temperatures during cryoballoon pulmonary vein isolation for atrial fibrillation

Background

Low oesophageal temperatures (OTs) during cryoballoon pulmonary vein isolation (PVI) have been associated with complications. This study assessed the incidence of low OT in clinical practice during cryoballoon PVI and verified possible predictive values for low OT.

Methods

Consecutive patients who underwent PVI using the second-generation cryoballoon were retrospectively included. The distance from the oesophagus to the different pulmonary veins (PVs) (OP distance), body mass index (BMI), sex, age, balloon temperature and application time were studied as potential predictors of low OTs. Computed tomography was performed before the procedure to determine the OP distance. OT was measured using an oesophageal temperature probe. Applications were ended prematurely if the OT reached <16 °C. Low and ultralow OT were defined as OT <20 and <16 °C respectively.

Results

Two hundred and four patients were included. Low OT was observed in 54 patients (26%) and 27 patients (13%) reached ultralow OTs. OP distance was the only predictor of low OTs after multivariate analysis. A cut-off value of 19 mm showed 96.2% sensitivity and 37.8% specificity in predicting low OTs. No clinically relevant relation was found between low OTs and BMI, age, sex, balloon temperature or application duration.

Conclusions

The incidence of low OT was 26% for cryoballoon PVI. OP distance was the only predictor of low OTs. Since an OP distance <19 mm was present in all patients in at least one PV, we recommend routine OT measurement during PVI cryoballoon therapy to prevent oesophagus-related complications.

Different tissue thermodynamics between the 40 W and 20 W radiofrequency power settings under the same ablation index/lesion size index

INTRODUCTION

The ablation index (AI) and lesion size index (LSI) are novel markers for predicting the ablation lesion quality, however, collateral damage is still a concern. This study aimed to compare the lesion characteristics and tissue temperature profiles between 20 W (20 Ws) and 40 W (40 Ws) ablation settings under the same AI and LSI.

METHODS

An ex vivo model consisting of swine myocardium (5-6 mm thickness) in a circulating, warmed saline bath was used. Twenty-one tissue temperature electrodes were used. Radiofrequency applications with different power settings were performed with a 10 to 12 g contact force until the AI and LSI reached 350 and 4.5, respectively.

RESULTS

A total of 120 radiofrequency (RF) applications and 2520 tissue temperature profiles were analyzed. The speed of the tissue temperature rise with 40 Ws was significantly faster than that with 20 Ws. However, the maximum tissue temperature did not significantly differ between 20 and 40 Ws with the same AI (44.6°C ± 3.9°C vs 45.1°C ± 6.4°C, P = .73), and was significantly lower for 40 Ws with the same LSI (42.8°C ± 3.4°C vs 40.0°C ± 3.4°C, P = .003). For both the AI and LSI, the number of electrodes exhibiting high temperatures (≥39°C) was significantly larger and the duration of high tissue temperatures was significantly longer with 20 Ws. The thermal latency with 40 Ws was greater.

CONCLUSIONS

Although the targeted AI and LSI were the same for both 20 and 40 Ws, the tissue temperature profiles differed greatly depending on the RF power setting. A high power setting based on the AI and LSI may reduce the collateral thermal damage.

Radiofrequency catheter ablation-induced gastroparesis successfully treated with administration of mosapride citrate: two case reports

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and radiofrequency catheter ablation (RFCA) for pulmonary vein isolation is a well-established therapeutic modality for AF. Transient gastroparesis rarely complicates RFCA. We report two cases of RFCA-induced transient gastroparesis, effectively treated with mosapride citrate administration. Case 1. Computed tomography (CT) performed 4 days after RFCA revealed marked gastric dilatation without any gastric or intestinal obstruction. The patient was fasting and was administered mosapride citrate (5 mg thrice a day). The patient's symptoms improved 6 days later, and CT revealed no gastric dilatation. Esophagogastroduodenoscopy revealed gastric peristalsis without residual food in the stomach. Case 2. CT performed 8 days after RFCA revealed marked gastric dilatation without any gastric or intestinal obstruction. The patient was fasting and was administered pantothenic acid (500 mg/day intravenously for 7 days). However, symptoms persisted, and CT revealed residual food in the stomach. The patient was subsequently administered mosapride citrate (5 mg thrice a day). The patient's symptoms improved 4 days later, and contrast-enhanced gastric X-ray using amidotrizoate meglumine revealed gastric peristalsis, passage of amidotrizoate meglumine into the duodenum, and no gastric dilatation. Mosapride citrate is useful to treat RFCA-induced gastroparesis.

Vagal schwannomas of the head and neck: A comprehensive review and a novel approach to preserving vocal cord innervation and function

BACKGROUND

Schwannomas, benign tumors arising from neurolemmocytes, are the most common type of peripheral nerve tumors. Extracranial schwannomas are most often found in the parapharyngeal space, commonly involving the vagus nerve to cervical sympathetic trunk. Vagal schwannomas present several unique clinical and therapeutic challenges.

METHODS

A comprehensive literature review was conducted on 197 articles reporting 235 cases of cervical vagal schwannomas. Presenting symptoms, treatment approach, and postoperative outcomes were recorded and analyzed.

RESULTS

Vagal schwannomas commonly present as asymptomatic neck masses. When they become symptomatic, surgical resection is the standard of care. Gross total resection is associated with higher postoperative morbidity compared to subtotal resection. Initial reports using intraoperative nerve monitoring have shown improved nerve preservation. Recurrence rates are low.

CONCLUSION

The combination of intermittent nerve mapping with novel continuous vagal nerve monitoring techniques may reduce postoperative morbidity and could represent the future standard of care for vagal schwannoma treatment.

Upper gastrointestinal complications following ablation therapy for atrial fibrillation

BACKGROUND

Following ablation therapy for cardiac arrhythmias, patients may develop upper gastrointestinal (UGI) symptoms. The vagus nerve is close to the atria and may be affected by ablating energy.

AIM

To identify structural or functional complications in UGI tract following ablation for atrial fibrillation (AF) and clinical outcomes and association with vagal dysfunction.

METHODS

Using natural language processing of electronic medical records and an AF ablation database of 5380 patients treated during 17 years, we identified 40 patients with UGI complications. We evaluated vagal dysfunction by electrocardiogram (ECG) showing lack of sinus arrhythmia (variation in R-R interval by ≥120 milliseconds, in presence of normal sinus P waves and constant P-R interval).

KEY RESULTS

Among 40 patients: (A) eight had structural GI complications confirmed by diagnostic tests: seven with esophageal ulcer/erosions and no signs of UGI bleeding and one developed esophagopericardial fistula (and survived with treatment); (B) 15 had functional UGI complications confirmed by objective motility tests. Nine had newly developed symptoms and six had aggravated symptoms; and (C) the remaining 17 had GI symptoms without relevant diagnostic results. Most UGI issues resolved spontaneously or with conservative treatment. However, 2 died several weeks after ablation procedure; cause of death was suspected atrioesophageal fistula or esophageal rupture. Vagal dysfunction persisted for 3 months in 13 and was transient in 8.

CONCLUSIONS/INFERENCES

Although most GI issues resolved spontaneously, there should be a high index of clinical suspicion in patients with persistent symptoms. Vagal dysfunction may serve as a marker of more extensive tissue damage.

Periesophageal vagal plexus injury is a favorable outcome predictor after catheter ablation of atrial fibrillation

BACKGROUND

Collateral damage to periesophageal vagal plexus associated with symptomatic gastric hypomotility and associated symptoms are not uncommon after catheter ablation of atrial fibrillation (AF). The injury may indicate transmural ablation lesions.

OBJECTIVE

The purpose of this study was to evaluate the periesophageal vagal plexus injury (PNI) and long-term outcome after catheter ablation of AF.

METHODS

A total of 441 consecutive patients with AF (mean age 54.71 ± 10.52 years; 134 women) who underwent catheter ablation (paroxysmal AF, n = 312; persistent AF, n = 129) were retrospectively enrolled from 2011 to 2013; group 1 was defined as patients with PNI and associated symptoms (n = 88), and group 2 was defined as patients without PNI or associated symptoms (n = 353). Baseline characteristics and electrophysiological properties were collected to analyze the relationship between PNI and clinical outcome. The association of AF recurrence after catheter ablation and PNI symptoms was also investigated.

RESULTS

During a mean follow-up period of 37.3 ± 0.94 months, group 1 had longer AF-freedom days in sinus rhythm after AF ablation and had less recurrence after the blanking period compared with group 2 (mean recurrence days, 1254.22 ± 45.26 days vs 1065.21 ± 33.35 days; P < .01). Multivariate analysis also revealed that PNI was an independently protective predictor of AF recurrence (hazard ratio 0.527; 95% confidence interval 0.289-0.959; P = .036). There was no difference in baseline characteristics, CHA2DS2-VASc score, or echocardiography follow-up duration.

CONCLUSION

PNI and associated symptoms are not uncommon after catheter ablation of AF. A better long-term outcome is thereby independently predicted, suggesting transmural ablation lesions during pulmonary vein isolation.

Impact of esophageal temperature monitoring guided atrial fibrillation ablation on preventing asymptomatic excessive transmural injury

Background

Even with the use of a reduced energy setting (20–25 W), excessive transmural injury (ETI) following catheter ablation of atrial fibrillation (AF) is reported to develop in 10% of patients. However, the incidence of ETI depends on the pulmonary vein isolation (PVI) method and its esophageal temperature monitor setting. Data comparing the incidence of ETI following AF ablation with and without esophageal temperature monitoring (ETM) are still lacking.

Methods

This study was comprised of 160 patients with AF (54% paroxysmal, mean: 24.0±2.9 kg/m²). Eighty patients underwent ablation accompanied by ETM. The primary endpoint was defined as the occurrence of ETI assessed by endoscopy within 5 d after the AF ablation. The secondary endpoint was defined as AF recurrence after a single procedure. If the esophageal temperature probe registered >39 °C, the radiofrequency (RF) application was stopped immediately. RF applications could be performed in a point-by-point manner for a maximum of 20 s and 20 W. ETI was defined as any injury that resulted from AF ablation, including esophageal injury or periesophageal nerve injury (peri-ENI).

Results

The incidence of esophageal injury was significantly lower in patients whose AF ablation included ETM compared with patients without ETM (0 [0%] vs. 6 [7.5%], p=0.028), but not the incidence of peri-ENI (2 [2.5%] vs. 3 [3.8%], p=1.0). AF recurrence 12 months after the procedure was similar between the groups (20 [25%] in the ETM group vs. 19 [24%] in the non-ETM group, p=1.00).

Conclusions

Catheter ablation using ETM may reduce the incidence of esophageal injury without increasing the incidence of AF recurrence but not the incidence of peri-ENI.

Gastroparesis as a Complication of Atrial Fibrillation Ablation

Percutaneous catheter ablation is a safe and effective treatment for symptomatic drug-resistant atrial fibrillation (AF). Gastroparesis is a little known complication of AF ablation. We aimed to evaluate the frequency of gastroparesis in the patients who underwent catheter ablation for AF by cryoballoon (CB) or radiofrequency (RF) and to define risk factors for gastroparesis. In all, 104 patients were treated with pulmonary vein (PV) isolation with 2 different technologies: CB in 58 patients (group 1) and open-irrigated tip RF catheter in 46 patients (group 2). Gastroparesis was seen in 7 cases (6 cases in group 1 and 1 case in group 2, respectively). The complaints related with gastroparesis began during the procedure in 4 of 6 patients of group 1. The other 3 patients admitted to our outpatient clinic with similar complaints within 72 to 96 hours after the procedure. For gastroparesis cases of group 1, mean minimal CB temperature on inferior PVs was lower and left atrium diameter was smaller. Management was conservative, and the patients have no residual symptoms at 6-month follow-up. The only patient still demonstrating residual symptoms during follow-up was in group 2. Although, clinically manifest gastroparesis is quite common with CB ablation, the process is generally reversible. However, damage may not be as reversible with RF ablation. In conclusion, during cryoablation, lower temperatures on inferior PVs and small left atrium size may be associated with increased risk of gastroparesis, and fluoroscopic guidance may be useful to avoid this complication.