Atrioesophageal Fistula in the Era of Atrial Fibrillation Ablation: A Review

The purpose of this review is to understand the epidemiology, clinical features, etiopathogenesis, and management of atrioesophageal fistula (AEF) after atrial fibrillation (AF) ablation. The incidence of AEF after AF ablation is 0.015%-0.04%. The principal clinical features include fever, dysphagia, upper gastrointestinal bleeding, sepsis, and embolic strokes. The close proximity of the esophagus to the posterior left atrial wall is responsible for esophageal injury during ablation. Prophylactic proton pump inhibitors, esophageal temperature monitoring, visualization of the esophagus during catheter ablation, esophageal protection devices, and avoidance of energy delivery in close proximity to the esophagus play an important role in preventing esophageal injury. Early surgical repair or esophageal stenting are the mainstay of treatment. Eliminating esophageal injury during AF ablation is of utmost importance in preventing AEF. A high index of suspicion and early intervention is necessary to prevent fatal outcomes.     

CT radiographic findings: atrio-esophageal fistula after transcatheter percutaneous ablation of atrial fibrillation

INTRODUCTION: Radio-frequency catheter ablation (RFCA) is an ever increasing modality for treating refractory atrial fibrillation. Radiologists should not only be able to interpret and convey anatomic variations of pulmonary veins and left atrium to referring electrophysiologists, but also should be aware of all the post-RFCA complications and their radiographic findings including this rare, but often fatal complication. This report describes a fatal atrio-esophageal fistula (AEF) involving a normal variant single left common pulmonary vein after transcatheter ablation. RESULTS: A 59-year-old man who presented to the Emergency Department (ED) with altered mental status previously complaining of fatigue and malaise. The patient underwent a total of 2 uneventful circumferential percutaneous pulmonary vein ablations for atrial fibrillation. The most recent was performed 5 weeks before admission to ED. Within hours of initial evaluation, the patient quickly deteriorated owing to overwhelming sepsis requiring both inotropic and ventilatory support. Transthoracic echocardiography within ED showed no evidence of valvular vegetation or gas bubbles in the left atrium. Computed tomography (CT) of the chest with intravenous contrast revealed findings compatible with AEF. Head CT was negative for ischemic changes or emboli. Patient underwent emergent cardiac and esophageal surgery at which point the patient later died on the operating table. CONCLUSIONS: Patients who present with signs and symptoms of endocarditis, and particularly with new neurologic symptom after RFCA should be promptly evaluated for AEF. In our case, radiographic findings in correlation with clinical history and high suspicion strongly suggested this rare, often fatal complication. During review of the chest CT, particular vigilance should be made to the left pulmonary vein/posterior left atrium junction at which site fistulous tracts tend to occur. Prompt diagnosis necessitates emergent cardiac and esophageal surgery to prevent rapid deterioration and death.     

Continuous nonfluoroscopic localization of the esophagus during radiofrequency catheter ablation of atrial fibrillation

Introduction : Atrial-esophageal fistula formation is a dreaded complication of radiofrequency catheter ablation for atrial fibrillation. Esophageal localization is of potential value in avoiding lesion placement where the left atrium is juxtaposed to the esophagus.
Methods and Results : Twenty-seven patients underwent 33 pulmonary vein encirclement procedures. All the patients received general anesthesia with inhalational agents and either a fenestrated laryngeal mask airway or an endotracheal tube. A diagnostic electrophysiologic catheter was inserted into the esophagus, and a virtual esophageal tube was created using an electroanatomic mapping system. In all cases, the catheter was placed without difficulty and satisfactory virtual esophageal images were created. The catheter remained in the esophagus until the end of each ablation procedure. Esophageal catheter location during and after the ablation was compared with the initial location. Areas of close proximity between the left atrium and esophagus were easily identified. Change in esophageal location was not observed. Identification of esophageal proximity to the pulmonary veins allowed for identification of high-risk cases. In such cases, the planned procedure was modified to avoid esophageal injury (12 of 27 patients).
Conclusions : (1) Real-time localization of esophageal position using a nonfluoroscopic mapping system during atrial fibrillation ablation is safe, practical, and straightforward. (2) Among patients who receive general anesthesia, esophageal position appears to be static, suggesting that one initial virtual image is sufficient for the duration of an ablation procedure.     

A nationwide survey on the prevalence of atrioesophageal fistula after left atrial radiofrequency catheter ablation

BACKGROUND: There are limited data on the prevalence of atrioesophageal fistula (AEF) after left atrial radiofrequency catheter ablation for atrial fibrillation (AF). The purpose of this study was to determine the prevalence and factors associated with AEF using a nationwide anonymous survey. METHODS AND RESULTS: The information solicited included the practice setting, number of left atrial ablations performed for AF, prevalence of AEF, clinical presentation and outcome of these patients, ablation strategy, type of ablation catheter, and energy settings used to deliver radiofrequency energy. The survey was mailed to 1,874 members of the Heart Rhythm Society within the US and 585 physicians responded (31%). AEF was reported in six of the 20,425 patients who underwent a left atrial ablation procedure (0.03%). All six patients suffered from major cerebrovascular events. Five of the six patients died (83%). The patient who survived had residual hemiparesis. There was no association between the risk of AEF and the case volume. In five patients, wide area circumferential ablation was performed. In the remaining patient, pulmonary vein isolation by ostial ablation was employed. In all cases an 8-mm tip ablation catheter was used. The power in patients who did and did not develop AEF were 58 +/- 13 and 41 +/- 9 W, respectively (P = 0.03). In one patient AEF occurred despite <1 degrees C rise recorded from an esophageal temperature probe. In the remaining patients no specific method was used to visualize the location of the esophagus. CONCLUSIONS: Based on the responses to the survey, the risk of AEF appears to be <1%. However, AEF is associated major cerebrovascular events and leads to death in >80% of the patients.     

Topographic variability of the esophageal left atrial relation influencing ablation lines in patients with atrial fibrillation

Topography of the esophagus in atrial fibrillation ablation. INTRODUCTION: The close anatomic relationship of the posterior wall of the left atrium (LA) and the thermosensitive esophagus creates a potential hazard in catheter ablation procedures. METHODS AND RESULTS: In 30 patients (pts) with atrial fibrillation (AF) undergoing catheter ablation, we prospectively studied the course and contact of the esophagus in relation to LA and the topographic proximity to ablation lines encircling the right-sided and left-sided pulmonary veins (PV) as well as to the posterior line connecting the encircling lines using the electromagnetic mapping system for reconstruction of LA and for tagging of the esophagus. This new technique of anatomic tagging of the esophagus was validated against the CT scan as a standard imaging procedure. The esophageal course was highly variable, extending from courses in direct vicinity to the left- or right-sided PV as well as in the midportion of the posterior LA. In order to avoid energy application in direct proximity to the esophagus, adjustments of the left and right PV encircling lines were necessary in 14/30 pts (47%) and 3/30 (10%). In 30 pts (100%), the mid- to inferior areas of the posterior LA revealed contact with the esophagus. Therefore, posterior and inferior linear ablation lines were abandoned and shifted to superior in 29 pts (97%). CONCLUSIONS: Anatomic tagging of esophagus revealed a highly variable proximity to different areas of the posterior LA suggesting individual adjustment of encircling and linear ablation lines in AF ablation procedures to avoid the life threatening complication of esophagus perforation.     

Intracardiac Ultrasound for Esophageal Anatomic Assessment and Localization During Left Atrial Ablation for Atrial Fibrillation

Intracardiac Ultrasound During Left Atrial Ablation for Atrial Fibrillation. Background: Esophageal injury during left atrial ablation is associated with a significant risk of mortality and morbidity. There are no validated approaches to reduce injury outside of avoidance, a strategy critically dependent on a precise understanding of the esophageal anatomy and location. Intracardiac ultrasound (ICE) can provide a real‐time assessment of the esophagus during ablation. We hypothesized that ICE can accurately define esophageal anatomy and location to enhance avoidance strategies during ablation. Methods: Fifty patients underwent atrial fibrillation (AF) ablation. The left atrium and pulmonary vein anatomies were rendered by traditional electroanatomic mapping (CARTO). A Navistar catheter within the esophagus was used to create a traditional electroanatomic esophageal anatomy. ICE imaging was used to create a second geometry of the esophagus. The traditional and ICE anatomies of the esophagus were compared and the greatest border dimensions used to avoid injury. Results: The average age was 66 ± 10 years, 45% had persistent/longstanding persistent AF, and 18% had a prior AF ablation. The esophagus location was leftward in 17 (34%), midline in 22 (44%), and rightward in 11 (22%). Traditional esophagus and ICE imaging correlated within 1 cm in the greatest distance in 26 (52%) patients. Traditional imaging underestimated the esophageal location by >1–1.5 cm in 9 (18%) and >1.5 cm in 15 (30%). In those with poor correlation (>1.5 cm), the most common cause was the presence of a hiatal hernia. Ablation energy delivery was performed outside the greatest esophagus anatomy borders. Of those with 12‐month follow‐up, 75% were AF/atrial flutter free without antiarrhythmic drugs. No esophageal injuries were observed. One patient experienced a TIA greater than 6 months postablation. Conclusion: These data demonstrate that traditional means of mapping the esophagus using a catheter within the esophagus are insufficient and often grossly underestimate the actual anatomy. Imaging techniques that define the complete esophageal lumen should be considered to truly minimize esophageal injury risk. (J Cardiovasc Electrophysiol, Vol. 24, pp. 33‐39, January 2013)     

Electroanatomic reconstruction of the left atrium, pulmonary veins, and esophagus compared with the "true anatomy" on multislice computed tomography in patients undergoing catheter ablation of atrial fibrillation.

BACKGROUND: Current concepts of catheter ablation for atrial fibrillation (AF) commonly use three-dimensional (3D) reconstructions of the left atrium (LA) for orientation, catheter navigation, and ablation line placement. OBJECTIVES: The purpose of this study was to compare the 3D electroanatomic reconstruction (Carto) of the LA, pulmonary veins (PVs), and esophagus with the true anatomy displayed on multislice computed tomography (CT). METHODS: In this prospective study, 100 patients undergoing AF catheter ablation underwent contrast-enhanced spiral CT scan with barium swallow and subsequent multiplanar and 3D reconstructions. Using Carto, circumferential plus linear LA lesions were placed. The esophagus was tagged and integrated into the Carto map. RESULTS: Compared with the true anatomy on CT, the electroanatomic reconstruction accurately displayed the true distance between the lower PVs; the distances between left upper PV, left lower PV, right lower PV, and center of the esophagus; the longitudinal diameter of the encircling line around the funnel of the left PVs; and the length of the mitral isthmus line. Only the distances between the upper PVs, the distance between the right upper PV and esophagus, and the diameter of the right encircling line were significantly shorter on the electroanatomic reconstructions. Furthermore, electroanatomic tagging of the esophagus reliably visualized the true anatomic relationship to the LA. On multiple tagging and repeated CT scans, the LA and esophagus showed a stable anatomic relationship, without relevant sideward shifting of the esophagus. CONCLUSION: Electroanatomic reconstruction can display with high accuracy the true 3D anatomy of the LA and PVs in most of the regions of interest for AF catheter ablation. In addition, Carto was able to visualize the true anatomic relationship between the esophagus and LA. Both structures showed a stable anatomic relationship on Carto and CT without relevant sideward shifting of the esophagus.     

Pulmonary vein isolation under direct visual identification of the left atrium—pulmonary vein junction using intra-cardiac echography

Introduction: Intra-cardiac echocardiography (ICE) which has some benefits, can be used to obtain detailed anatomy of the heart chambers or large vessels, and the catheter positions, and it has been considered useful for improving the outcome of the ablation. In the present study, we performed pulmonary vein isolation (PVI) under real time monitoring of ICE imaging utilizing an ICE catheter placed at the junction of the left atrium (LA) and PVs (LA-PV junction). Methods: PVI for atrial fibrillation (AF) was performed in 30 cases with drug-resistant AF (mean age: 66-years-old; including 22 males). An ICE catheter utilizing a 9 MHz frequency was inserted into the LA via the atrial septum, and placed at the LA-PV junction. Circumferential ablation was performed in the LA outside of the PV ostium, encircling both the superior and inferior ostia together under ICE imaging. Results: The anatomy of the LA to the PVs and catheter sites were clearly identified by the ICE during the procedure, which enabled a precise and safe catheter manipulation with minimal fluoroscopy. Further, the wall thickness of the PV and LA, and position of the esophagus could be obtained by ICE, facilitating care in adjusting the power and/or duration of the current delivery. Conclusion: ICE imaging of the LA-PV junction permitted real time monitoring of the target sites for PVI during the ablation procedure, and was considered a useful technique for performing PVI.     

Real-Time Rotational ICE Imaging of the Relationship of the Ablation Catheter Tip and the Esophagus During Atrial Fibrillation Ablation

Introduction: Atrioesophageal fistula is a rare complication of atrial fibrillation (AF) ablation that should be avoided. We investigated whether rotational intracardiac echocardiography (ICE) can help to minimize ablation close to the esophagus.
Methods and Results: We studied 41 patients referred for catheter ablation of refractory AF. A rotational ICE catheter was inserted into the (LA) to determine the location of the esophagus. The esophagus was identified to be either adjacent to the pulmonary vein (PV) ostium or to a cuff 2 cm outside the ostium. Circumferential ablation was performed at the PV ostium, with the exact ablation location determined by ICE. The relationship of the catheter tip to the esophagus was imaged during energy delivery, allowing interruption when respiration moved the tip closer to the esophagus. Out of 41 patients, the esophagus was seen near left-sided PVs in 32 and near right-sided PVs in three patients. The median distance from LA endocardium to esophagus was 2.2 mm (range, 1.4–6 mm). In 21 of 35 patients with a closely related esophagus, ablation over the esophagus was avoided by ablating either lateral or medial to the esophagus. In 14 patients, the esophagus could not be avoided, and risk was minimized by limiting lesion size. Significant movement (>10 mm) of the esophagus during the procedure occurred in 3/41 cases.
Conclusion: Rotational ICE can accurately determine the distance of ablation sites from the esophagus. Real-time imaging of the relationship of the ablation catheter tip to the esophagus may reduce the incidence of esophageal injury.     

左心房及肺静脉同步食管CT血管成像在心房颤动射频消融术中的辅助作用

目的:心房-食管瘘是心房颤动介入及心脏外科手术射频消融治疗中少见但严重的并发症,伴有极高的病死率。最安全有效的预防心房-食管瘘发生的方法,应当是术前了解左心房、肺静脉及周围脏器解剖关系,预防消融烧伤食管心房段。我们进行了术前64层螺旋CT(64层MSCT)左心房及肺静脉成像同时引入食管造影检测食管和左心房的毗邻关系。方法:232例左心房及肺静脉成像(心房颤动组146例,对照组86例),同步进行食管联合造影,即注射造影剂的同时食管吞入造影剂,以观察食管走形和左心房的关系。根据食管心房后壁段与上下PV的关系将食管走形分为:I、II型,其中各型又分别分为abc三种亚型。融合影像的同时,在CARTO系统上显示LA-PV及ESO的三维重建关系,以指导完成肺静脉隔离。结果:228例患者中,I型-Ia39例(心房颤动组24例、对照组15例),占17.11%,Ib55例(心房颤动组39例、对照组16例),占24.12%,Ic 76例(心房颤动组48例、对照组28例),占33.33%;II型-IIa27例(心房颤动组16例、对照组11例),占11.84%,IIb18例(心房颤动组10例、对照组8例),占7.89%,IIc13例(心房颤动组7例、对照组6例),占5.70%。食管跨左心房后壁段长度平均为(55.04±9.01)mm[心房颤动组(54.77±9.49)mm、对照组(55.51±8.14)mm],食道厚度约为(2.26±0.64)mm[心房颤动组(2.25±0.63)mm、对照组(2.30±0.65)mm],左心房后壁厚度中位数房颤组0.6mm(0.3mm,2.9mm)、对照组1.4mm(0.3mm,2.9mm)。食道前壁距左心房最小距离中位数房颤组1.75mm(0mm,5mm)、对照组2.15mm(0mm,4.4mm)。所有心房颤动组患者均完成了肺静脉隔离。结论:本中心完成一组大样本量国人食道左心房肺静脉CT成像,提出6种分型,但心房颤动组和对照组数据在长度、厚度、距离和分型上无明显差异。利用融合影像学技术在射频消融术中指导解剖位置,提高手术安全性。     

Three-dimensional esophagus reconstruction and monitoring during ablation of atrial fibrillation: Combination of two imaging techniques

Objective

The purpose of the study was to determine the accuracy of a novel three-dimensional (3D) imaging integration technique of the esophagus combining multislice computed tomography (CT) scan of the esophagus into the three-dimensional (3D) electroanatomic map just before pulmonary vein (PV) isolation.

Methods

We included 94 consecutive patients with symptomatic atrial fibrillation (AF) who underwent ablation. All patients had a CT performed prior procedure that was integrated to the 3D reconstruction electromechanical map of the atrium and the esophagus (Verismo^TM, EnSite® NavX version 7.0J, St. Jude Medical Inc.). During the procedure, a quadripolar electrophysiology catheter placed in the esophagus was used for mapping and to monitor esophagus position. Integrated (fusion) images were used to determinate the esophagus position compared to the left atrium posterior wall and its relationship with PV ostiums. We compared esophagus position by CT and fusion images.

Results

Procedural success was 97.9% with no fatal complications. Esophagus locations were as follows: left 57%, right 7%, oblique course 11% and central 25%. Agreements in esophageal position between CT and fusion imaging techniques were 83.3% and 64% for patients with a recent (≤ 48 h) and non-recent CT assessment (> 48 h), respectively. Throughout the procedure, esophagus stability was 88.8% (lateral displacement < 15 mm). Ablative strategy was modified in 51% of the cases due to awareness of esophagus location.

Conclusion

Guidance of AF ablation with 3D fusion images was safe and effective. CT images of the esophagus, especially if acquired within 48 h before ablation, ensure appropriate intraprocedural localization of the esophagus.     

Anatomic relationship of the esophagus and left atrium: implication for catheter ablation of atrial fibrillation

STUDY OBJECTIVES: Atrioesophageal fistulas have been reported to be a lethal complication following catheter ablation of atrial fibrillation (AF). The purpose of this study was to investigate the relationship between the esophagus and posterior left atrium (LA) and provide the anatomic information necessary to minimize the risk of esophageal injury during AF ablation. METHODS AND RESULTS: Forty-eight patients (43 men; mean +/- SD age, 59 +/- 12 years) with drug-refractory paroxysmal AF and 32 control subjects (26 men; mean age, 60 +/- 9 years) were included. All underwent a CT scan for delineation of the relationship between the esophagus and posterior LA. In the paroxysmal AF group, two major types of esophageal routes were demonstrated. Type 1 routes were found in 42 patients with the lower portion of esophagus close to the ostium of the left inferior pulmonary vein (LIPV), including three subtypes of courses according to the proximity to the left superior pulmonary vein (PV) and LIPV. Type 2 routes were found in six patients with the lower portion of esophagus close to the ostium of the right inferior pulmonary vein (RIPV), including three subtypes of courses according to the proximity to the right superior PV and RIPVs. The mean shortest distance of the esophagus to the four individual PVs significantly differed between type 1 and type 2: 28.4 +/- 6.1 mm vs 10.5 +/- 5.7 mm (to the right superior), 19.6 +/- 7.0 mm vs 3.7 +/- 3.4 mm (to the right inferior), 10.1 +/- 3.4 mm vs 22.8 +/- 4.2 mm (to the left superior), and 2.8 +/- 2.5 mm vs 18.7 +/- 5.2 mm (to the left inferior), respectively (p < 0.001 for all). Contact of the esophagus and middle part of posterior LA was observed in each patient. However, direct contact of the aorta with the posterior LA wall was more frequent in type 2 than in type 1 (p = 0.001). The clinical characteristics, type of esophageal routes, distance from the esophagus to the four PVs, and diameter of the thoracic cage, LA, and aorta in the control group were similar to those in the AF group (p > 0.05 for all). CONCLUSION: Although the anatomic relationship between the esophagus and LA posterior wall varied widely, two major patterns of esophageal routes could be depicted. This information is important for deciding the location of the ablation lesions around the PV ostia and LA and for avoiding the potential risk of esophageal injury.     

Mechanical esophageal displacement during catheter ablation for atrial fibrillation

Esophageal Deviation in AF Ablation. Objective: To determine the feasibility and safety of esophageal displacement during atrial fibrillation (AF) ablation, to prevent thermal injury. Background: Patients undergoing AF ablation are at risk of esophageal thermal injury, which ranges from superficial ulceration, to gastroparesis, to the rare but catastrophic atrioesophageal fistula. A common approach to avoid damage is luminal esophageal temperature (LET) monitoring; however, (1) temperature rises mandate interruptions in energy delivery that interrupt workflow and potentially decrease procedural efficacy, and (2) esophageal fistulas have been reported even with LET monitoring. Methods: A cohort of 20 consecutive patients undergoing radiofrequency (RF) (16 patients) or laser balloon (4 patients) ablation of AF under general anesthesia. After barium instillation, the esophagus was deviated using an endotracheal stylet placed within a thoracic chest tube. LET monitoring was used during catheter ablation. Upper GI endoscopy was performed prior to discharge. Results: At the pulmonary vein level, leftward deviation measured 2.8 ± 1.6 cm (range: 0.4–5.7) and rightward deviation 2.8 ± 1.8 cm (range: 0.5–4.9). The temperature rose to >38.5 °C in 3/20 (15%) patients. In these 3 patients, there was an average of 2 applications/patient that recorded temperatures >38.5 °C. No patient had a temperature rise > 40 °C. Endoscopy revealed no esophageal ulceration from thermal injury in 18/19 (95%) patients; the sole patient with a thermally mediated ulceration had an unusual esophageal diverticulum fully across the posterior left atrium. Twelve patients (63%) exhibited trauma related to instrumentation with no clinical sequelae. Conclusions: Mechanical esophageal deviation is feasible and allows for uninterrupted energy delivery along the posterior wall during catheter ablation of AF. J Cardiovasc Electrophysiol, Vol. 23, pp. 147‐154, February 2012)     

Relationship of the esophagus and aorta to the left atrium and pulmonary veins: Implications for catheter ablation of atrial fibrillation

BACKGROUND: A potential complication during ablation of atrial fibrillation (AF) is damage to adjacent structures such as the esophagus and aorta. Fatal atrio-esophageal fistulas have developed after surgery- or catheter-based AF ablation procedures. OBJECTIVES: The purpose of this study was to analyze multidetector computed tomography (MDCT) angiographic images to determine the anatomic relationship of the aorta and esophagus to the left atrium (LA). METHODS: Sixty-five subjects underwent CT imaging using a 16-slice MDCT scanner: 24 with paroxysmal AF, 21 with chronic AF, and 20 "control" subjects without a history of AF. Measurements assessed included LA diameters, width of the esophagus and aorta in contact with the posterior LA wall, and distance from the esophagus to the four pulmonary veins (PVs), spine, and LA endocardium. RESULTS: Mean LA diameters were significantly larger in patients with AF vs the control group (P = .003 for anteroposterior diameter; P = .009 for transverse diameter). The anterior aspect of the esophagus was directly apposed to the LA in all cases (contact width 18.9 +/- 4.4 mm). The position of the esophagus varied in the posterior mediastinum but on average was closer to the ostia of the left PVs (P = .0001). The descending aorta was in contact with the LA and/or left PVs in 50 of 65 subjects. The esophagus was closer to the spine in the chronic AF vs control group (P = .007), likely due to increased LA dimension. CONCLUSION: In addition to its ability to assess PV anatomy, preprocedural MDCT imaging can investigate the variable relationship of adjacent structures, such as the esophagus and aorta to the LA and PVs.     

Novel imaging techniques of the esophagus enhancing safety of left atrial ablation

This report describes different imaging techniques of the esophagus in four patients during radiofrequency catheter ablation of atrial fibrillation in the left atrium. A novel use of a mixture of barium cream and gadolinium diglutamate allowed esophageal imaging during magnetic resonance angiography of the left atrium and pulmonary veins. Barium cream used during computer tomography angiographic imaging of the left atrium and pulmonary veins allowed esophageal imaging. The esophagus was also imaged with an electroanatomic mapping system. Esophageal and left atrial imaging helped to avoid catheter ablation in left atrial tissue overlapping the esophagus.     

Real-time monitoring of luminal esophageal temperature during left atrial radiofrequency catheter ablation for atrial fibrillation: observations about esophageal heating during ablation at the pulmonary vein ostia and posterior left atrium

INTRODUCTION: Left atrial radiofrequency catheter ablation (RFA) is gaining acceptance as treatment for drug-refractory atrial fibrillation (AF). This therapy has been associated with esophageal injury and atrioesophageal fistula formation causing death. METHODS: We describe 3 patients undergoing catheter ablation for AF during real-time monitoring of luminal esophageal temperature. RESULTS: We observed heating of the esophagus during short duration low power RFA, at either the left or right pulmonary vein ostia. Cryoablation at the pulmonary vein ostium in one patient resulted in esophageal cooling. Furthermore, we observed that fluoroscopic localization of the ablation catheter at a site apparently distant from the esophagus is not adequate to assure avoidance of ablation-induced esophageal heating. CONCLUSIONS: Real-time monitoring of luminal esophageal position and temperature is feasible, enhances recognition of esophageal heating, and may add useful information beyond that provided by fluoroscopic assessment of esophageal position. There is a potential role for esophageal monitoring to help avoid thermal injury to the esophagus during catheter ablation for atrial fibrillation.     

Prevention of esophageal thermal injury during radiofrequency ablation for atrial fibrillation

Pulmonary vein isolation using radiofrequency ablation is an effective therapy in patients with atrial fibrillation. However, the esophagus descends in close proximity to the posterior wall of the left atrium and renders this structure susceptible to thermal injury. Esophageal ulceration has been hypothesized to be a precursor to left atrial-esophageal fistula, a procedural complication associated with poor prognosis. In this review, we have analyzed and summarized the published data regarding esophageal thermal injury during catheter ablation for atrial fibrillation and strategies to minimize risk of this complication. While esophageal temperature monitoring can be useful, multiple factors such as patient characteristics and specific strategies for radiofrequency energy delivery also merit consideration.     

Safety of single transseptal puncture for ablation of atrial fibrillation: retrospective study from a large cohort of patients

Introduction: Transseptal puncture (TSP) is the conventional approach to assess the left atrial chamber. This technique has been widely used in interventional cardiology and, in the last years, this approach is mostly applied to electrophysiologic procedures. For atrial fibrillation (AF) ablation, two or more transseptal sheaths are often positioned in the left atrium in the majority of centers, therefore requiring two or more transseptal punctures. Theoretically, double puncture could bear additional risks or could increase the risk of persistence of septal defects. We reported the results of a retrospective analysis of a single transseptal puncture as a simplified approach for positioning multiple catheters in the left atrium during AF ablation. Methods: Between November 2003 and November 2005, 1,150 consecutive patients (mean age 54 ± 8 years, 75% men) were considered for AF ablation and underwent single transseptal puncture for positioning multiple catheters in the left atrium. Results: In only 6 of 1,150 (0.5%) cases a second transseptal puncture was required to position the ablation catheter in the left atrium. Neither acute complications related to transseptal catheterization such as atrial or aortic perforations, pericardial tamponade, thrombotic formation, or air embolism, nor complications due to the attempts of crossing the septum with the ablation catheter were reported. In all cases, each mapping catheter was properly maneuvered at different sites in the left atrium and at the pulmonary veins. In no patient was a residual septal atrial defect after the transseptal maneuvers detected during a mean follow up of 14 ± 2 months. Conclusions: This retrospective study on a large cohort of patients shows that single transseptal puncture for positioning two or more catheters in the left atrium for AF ablation is a highly successful and safe maneuver with a very low morbidity in the majority of patients. This may avoid potential complications related to a second transseptal puncture.     

Formula to estimate left atrial volume using antero-posterior diameter in patients with catheter ablation of atrial fibrillation

In patients undergoing atrial fibrillation (AF) ablation, an enlarged left atrium (LA) is a predictor of procedural failure as well as AF recurrence on long term. The most used method to assess LA size is echocardiography-measured diameter, but the most accurate remains computed tomography (CT).The aim of our study was to determine whether there is an association between left atrial diameters measured in echocardiography and the left atrial volume determined by CT in patients who underwent AF ablation.The study included 93 patients, of whom 60 (64.5%) were men and 64 (68.8%) had paroxysmal AF, who underwent AF catheter ablation between January 2018 and June 2019. Left atrial diameters in echocardiography were measured from the long axis parasternal view and the LA volume in CT was measured on reconstructed three-dimensional images.The LA in echocardiography had an antero-posterior (AP) diameter of 45.0 ± 6 mm (median 45; Inter Quartile Range [IQR] 41–49, range 25–73 mm), longitudinal diameter of 67.5 ± 9.4 (median 66; IQR 56–88, range 52–100 mm), and transversal diameter of 42 ± 8.9 mm (IQR 30–59, range 23–64.5 mm). The volume in CT was 123 ± 29.4 mL (median 118; IQR 103–160; range 86–194 mL). We found a significant correlation (r = 0.702; P < .05) between the AP diameter and the LA volume. The formula according to which the AP diameter of the LA can predict the volume was: LA volume = AP diam³ + 45 mL.There is a clear association between the left atrial AP diameter measured on echocardiography and the volume measured on CT. The AP diameter might be sufficient to determine the increase in the volume of the atrium and predict cardiovascular outcomes.     

多层螺旋CT和Ensite3000标测系统测量左心房食管间距离的相关性研究

目的:探讨多层螺旋CT下和Ensite3000标测系统下左心房食管间距离的相关性.方法:选择20例阵发性心房颤动患者,分别于导管射频消融前行多层螺旋CT测量左心房食管间距离及于消融术中在Ensite3000标测系统下测量左心房食管间距离,并比较其相关性.结果:多层螺旋CT测量的左心房食管间最短距离为(3.5±0.8)mm,三维标测系统测量的左心房食管间最短距离为(3.2±1.1)mm,Pearson相关分析表明,2种方法测量下的左心房食管间最短距离呈正相关(r=0.8,P<0.05).结论:Ensite3000标测系统下测量左心房食管间距离可行,间接说明远离左心房后壁或避开与食管紧靠的左心房后壁的心房颤动导管射频消融策略在临床上可行.