Atrioesophageal fistula after radiofrequency catheter ablation for atrial fibrillation: clinical case

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BACKGROUND

Atrial fibrillations are the most widespread and stable form of supraventricular tachyarrhythmia, characterized by chaotic electric activity in the atriums and by the absence of their effective contractions [1]. The incidence of atrial fibrillations in general population is 2–4%, and, according to the prognoses, by the year 2050, the number of patients with this rhythm disorder can double [1]. Atrial fibrillations are associated with worsening of the quality of life, resulting from the increased risk of developing stroke, cardiac failure and cognitive disorders, also representing a significant burden for the healthcare system [2].

Catheter ablation, in particular, the radiofrequency one, has become a routine procedure in the treatment of atrial fibrillations in recent years. According to the updated recommendations from the European Society of Cardiology (ESC, 2024), radiofrequency catheter ablation is considered the first line therapy for patients with symptomatic paroxysmal atrial fibrillations even without the preliminary prescription of antiarrhythmic drugs (class I, level of evidence — A) [3]. The efficiency of the procedure, confirmed during the large-scale international randomized research (EARLY-AF, STOP-AF First, Cryo-FIRST), as well as in the population of patients with cardiac failure (research works — CASTLE-AF, CABANA-HF), is manifesting as a significant decrease in the rate of atrial fibrillations recurrences, as the improvement in the quality of life among the patients and also as a decrease in the risk of cardio-vascular mortality and of hospitalizations [4, 5]. However, despite the high efficiency and the relative safety of the method, radiofrequency catheter ablation may be accompanied by various complications [6]. One of the rarest and the most dangerous complications is the development of the atrioesophageal fistula — the pathological communication path between the lumen of the esophagus and the cavity of the left atrium, occurring generally in 2–6 weeks after the procedure [6]. The incidence of cases of atrioesophageal fistula after radiofrequency catheter ablation varies from 0.04% to 0,25%, while the mortality reaches 63–100% [7, 8].

The clinical case of developing the atrioesophageal fistula after the radiofrequency catheter ablation procedure performed due to the presence of atrial fibrillations and complicated subsequently by stroke, sepsis and lethal outcome, presented in this article, draws the attention to the necessity of early detection of this rare complication, as well as to discussing the possible approaches for its prevention and treatment.

CLINICAL CASE DESCRIPTION

Patient info

Female patient Kh., aged 53 years, transported by an ambulance crew to the Emergency In-patient Department with the provisional diagnosis of acute cerebrovascular event (the patient was found by her daughter at her home in the unresponsive state: not capable of answering the questions, not reacting to the external irritants). On admission, according to the data from the general examination, the overall status was considered severe; level of consciousness — deep coma; the palpebral fissures are even; the pupillary photo-response is decreased; weakness in the lower half of the mimic muscles on the left side; tetraplegia; the muscle tone is decreased; the tendon reflexes in the limbs are decreased; the objective evaluation using the scale for neurological disorders when suspecting the presence of stroke (National Institutes of Health Stroke Scale, NIHSS) was 42 points (severe stroke, critical neurological deficit); signs of dysphagia; the heart rate was 98 bpm; the blood pressure with a background of vasopressor support was 110/70 mm.Hg.; breathing — via the artificial pulmonary ventilation equipment.

Case history. It is known that during the last two years the patient has twice undergone the radiofrequency catheter ablation of the cavotricuspid isthmus due to atrial flutter and the isolation of the orifices of the pulmonary veins and of the posterior wall of the left atrium due to having atrial fibrillations. It is also known that, due to the detected pericardial-esophageal fistula, on day 18 after the second catheter ablation procedure, the female patient spent 15 days receiving in-patient treatment with draining of the pericardium, with endoscopic draining of the esophagus, with endoscopic treatment of esophagus wound with negative pressure (negative pressure wound treatment, NPWT), with antibacterial therapy and, after the stabilization of her status, she was discharged for home stay in generally satisfactory status. Besides the rhythm disorders, the female patient was suffering from arterial hypertension, obesity (body mass index 34.9 kg/m²) and gastric ulcers (in the remission phase).

Laboratory and instrumental diagnosis

On the hospitalization day (in 2 days after the previous discharge from the In-patient Department), for the purpose of ruling out the acute cerebrovascular event, computed tomography (CT) and CT-perfusion of the brain were done along with the CT-angiography of brachiocephalic arteries, all showing no detectable pathological changes (Fig. 1).

 

Fig. 1. Computed tomography image of the brain in the axial plane (a–j): pathological changes not detected (10 points of the scale of early ischemic changes for stroke, ASPECTS).

 

In 2 hours, according to the data from the magnetic resonance imaging (MRI) of the brain, in the frontal, the parietal and the occipital lobes of the brain, in the thalamus on the left side and in both cerebellar hemispheres, the findings included the variously sized foci of true diffusion restriction, which corresponded to the developing ischemic acute cerebrovascular event of the cardioembolic type in circulatory regions of the right and the left middle cerebral arteries, of the left posterior cerebral arteries, as well as in the arteries of vertebrobasilar circulation system (Fig. 2).

 

Fig. 2. Magnetic resonance tomogram of the brain in the axial plane with using the DWI mode (diffusion weighted imaging) b1000 (b, d, f, h) with corresponding measurable diffusion coefficient maps (a, c, e, g): in the frontal, the parietal and the occipital lobes in the brain, in the thalamus on the left side, in both cerebellar hemispheres, the foci of true diffusion restriction were visualized, being the signs of ischemia foci.

 

Conservative and supporting therapy were arranged, with a background of which, the status of the patient remained extremely severe.

Due to the laboratory findings showing the progressing inflammation, on day 6 after hospitalization, the CT of the esophagus with oral contrasting via the nasogastral tube was carried out: the findings were the spreading of the contrasting agent from the lumen of the middle third of the esophagus into the left atrium cavity, which was judged as signs of atrioesophageal fistula, other findings in the fistulous tract and in the left atrial cavity included the presence of gas bubbles (Fig. 3). Simultaneously, due to the aggravation of the neurological status, the brain CT was performed for the purpose of evaluating the dynamic changes: within the brain matter, multiple foci of decreased density (approximately 18 HU) were visualized; the left transverse sinus and the brain vessels had foci with a density of approximately -978 HU, which were judged as the manifestations of cerebral aeroembolism (Fig. 4).

 

Fig. 3. Computed tomography image of the esophagus with oral contrasting in the axial plane in the pulmonary (a) and the bone (b) windows: the findings include air bubbles in the cavity of the left atrium (red arrow) and the spreading of the contrasting agent along the fistulous tract between the lumen of the middle third of the esophagus and the cavity of the left atrium (white arrow).

 

Fig. 4. Computed tomography image of the brain in the axial plane (a–d): the hemispheres of the brain contain the visualized foci of decreased density (white arrows) and foci of air density in the area of the left transverse sinus, in the cortical vessels of the brain (red arrows).

 

Diagnosis

Based on the conducted examinations, the main diagnosis set was the following: “Multiple infarctions of the brain within the circulatory systems of the right and the left middle cerebral arteries, of the left posterior cerebral artery, of the arteries in the vertebrobasilar system (embolic subtype). Tetraplegia. Dysphagia”. The concomitant diagnosis, according to the data from previous discharge documents, was the following: “Esophageal-pericardial fistula. Fibrinous pericarditis. Draining of the pericardium”. The background diagnosis was the following: “Hypertensive disease stage III, risk of cardio-vascular complications — 4. Heart rhythm disorder: persistent form of atrial fibrillations. S/p double radiofrequency catheter ablation”.

Therapy

The status of the patient remained severe, respiratory support was applied (artificial pulmonary ventilation), as well as the antibacterial therapy and the replacement renal therapy.

Dynamic changes and outcomes

Despite the conducted therapy, the patient had progressing signs of sepsis, of the multisystem organ failure, with unstable circulatory parameters, which led to the lethal outcome.

Timelines

The timings of the developing disease, the key events and the prognosis are provided in Fig. 5.

 

Fig. 5. Female patient H., 53 years: timelines of disease development, the key events and prognosis. RFA — radiofrequency ablation; AFl — atrial flutter; AF — atrial fibrillations; AEF — atrioesophageal fistula; MRI — magnetic resonance imaging; CT — computed tomography; CTA — CT-angiography; BCA — brachiocephalic arteries.

 

DISCUSSION

Pathophysiologically, the atrioesophageal fistula after radiofrequency catheter ablation develops as a result of thermal or ischemic damage of the esophageal wall adjacent to the posterior wall of the left atrium [9]. The anatomic proximity of the esophagus to the left pulmonary veins and to the posterior wall of the atrium, especially in patients with the increased left atrium and with the thinned layer of fatty tissue, increases the damage risk [9]. Additional factors can be the gastroesophageal reflux disease, the high ablation power (>30 Watt), the temperature increase of >40°C in the esophagus, as well as the long-term energy exposure during the radiofrequency catheter ablation [10, 11].

The clinical manifestations of atrioesophageal fistula are non-specific and include fever, chest pain and neurological symptoms, also including the strokes caused by the air or bacterial embolisms, which complicates the early diagnostics [12]. In our case, the female patient, during the initial detection of the atrioesophageal fistula, had complaints of dyspepsia and fever up to 38.5°C. During her last hospitalization, she already had the acute neurological symptoms expressed as the impaired consciousness and tetraplegia.

For the diagnostics of this complication, various radio-diagnostic methods can be used, however, currently there is no standard protocol for the visualization of the atrioesophageal fistula [13]. According to the literature review by H.C. Han et al. [8], which analyzed the data from 112 patients with atrioesophageal fistula after the radiofrequency catheter ablation, in 97 cases, chest CT was done, in 74 — CT with contrast enhancement. Based on these results, 98% of the cases were showing the pathological changes, namely the following: free gas in the mediastinum, pericardially or in the left ventricle (53%); the presence of the esophageal-atrial fistulous tract (10%); signs of mediastinitis (1%) and esophageal perforation (5%); changes in the left atrium, in particular, thrombus, diverticle or changes of the wall thickness (7%). At the same time, in 7 patients, the primary CT-scanning of the chest cavity organs did not reveal any abnormalities and only the repeated examination was able to reveal the pathological changes.

Besides the CT with intravenous contrasting, some authors prefer the oral contrasting method, in which the detection of the contrasting agent in the esophagus and in the surrounding posterior mediastinum is the main diagnostic criterion of atrioesophageal fistula. The authors have also found other important data, which can be related to the atrioesophageal fistula: the narrowing and the unevenness of the pulmonary vein, the thickening of the posterior wall of the left atrium, the fatty induration of the posterior mediastinum and the pneumomediastinum [14, 15].

The research work by A. Abdelradi et al. [16] recommends the CT-scanning of the chest cavity organs with oral and intravenous contrasting, if there are no contraindications and if the patient status allows doing so, but there are certain specific features of arranging the oral contrasting in cases of the patient with orogastric or nasogastric tubes, as they (tubes) may bypass the area of the suspected defect in the middle third of the esophagus. In such cases, before the conduction of oral contrasting, the tube should be lifted proximally to the suggested defect area. For more precise visualization of the end of the lifted tube, the possible procedures are the radiography of the chest cavity organs or the non-contrast CT. It is also important that the oral contrast is introduced directly before scanning due to the short esophageal transit time [16].

CT-signs of atrioesophageal fistula can be divided into the main and the indirect ones. The main signs include the extravasation of the contrasting agent from the esophagus into the atrium when conducting the examinations with oral or tube-mediated contrasting, as well as the extravasation of the contrasting agent from the atrium to the esophagus upon the intravenous administration. The indirect signs include the presence of air in the left atrium or in the pericardium, as well as the paraesophageal abscesses, the thickening of the esophageal wall, the thickening of the posterior wall of the left atrium, the infiltration of the posterior mediastinal fatty tissue, the pericardial effusion, the pneumomediastinum, the cerebral air embolism and the changes in the pulmonary veins expressed as thinning, ulceration or thickening of their walls. In our case, the patient had the detected signs of an acute cerebrovascular event on admission according to the data from MRI, though the previous brain CT and CT-perfusion did not detect any abnormalities. Upon the non-contrasted CT-scanning of the chest cavity organs, there were congestive signs found in both lungs along with signs of pulmonary hypertension and cardiomegaly. On the 5th day, the brain CT was already showing signs of an ischemic type subacute cerebrovascular event in the circulatory areas of the middle cerebral arteries and of the left posterior cerebral artery. On day 6, the dynamic brain CT was showing signs of aeroembolism, while the CT of the esophagus with oral contrasting was showing the spreading of the contrasting agent along the fistulous tract between the lumen of the middle third of esophagus and the cavity of the left atrium, as well as the presence of free gas in the left atrial cavity.

MRI is used more rarely due to the limited accessibility and due to the motion sensitivity, however, it can be useful in separate cases, especially when there are contraindications for conducting the CT (for example, in case of patients allergic to the contrasting agent) [8]. MRI can detect signs of inflammation, swelling and abscesses in the paracardial and paraesophageal tissues, however, the visualization of the fistula itself is difficult [8].

Brain CT can be useful in cases of atrioesophageal fistula, especially in cases of neurological deficit: thus, 40–50% of the patients, according to the data from brain CT, most commonly had the diffuse air embolism and multiple foci of ischemia in various circulatory zones in the brain [8, 17–22]. In our case, the initial MRI has revealed signs of acute cerebrovascular event of the ischemic type, while the CT was showing signs of cerebral embolism as a consequence of air from the esophagus entering the systemic circulatory system. The location of aeroembolism in a specific area has a major importance for the purpose of defining the etiology, for the intravenous gas is most frequently observed in the cavernous sinuses, in the lower petrosal sinuses or in the extracranial veins. The gas in the cerebral arteries indicates the presence of arterial-venous fistulas or the dextralateral shunt [23]. In our case, the air was detected in the left transverse sinus and in the distal areas of the brain vessels.

The transthoracic echocardiography and the transesophageal echocardiography are not recommended as the first line methods when suspecting the presence of atrioesophageal fistula [8], besides, transesophageal echocardiography may lead to the clinical worsening due to pumping air during the procedure, with this, in rare cases, using these methods, one can detect the indirect signs of the atrioesophageal fistula, such as the hydropericardium, the pneumopericardium and the air in the left atrium. In our clinical case, the transthoracic echocardiography has revealed the insignificant hydropericardium.

In the presented clinical case, the diagnosis of atrioesophageal fistula was set intravitally based on the data from CT with oral contrasting, which allowed for timely initiating the combined treatment, including the draining of the pericardium, the endoscopic draining of the esophagus and the installation of the NPWT-systems. However, despite the conducted therapy, the patient has developed an ischemic stroke, sepsis and multi-organ system failure, which has ultimately led to the lethal outcome.

The treatment of the atrioesophageal fistula remains a difficult task. Conservative therapy and stenting of the esophagus are associated with extremely high mortality (up to 100%), while the surgical intervention allows for decreasing the mortality down to 33–41% [24, 25]. In separate cases, temporary stenting of the esophagus is possible with further surgical correction, especially in patients that are not ready for immediate surgery [24]. In the presented case, due to the positive changes in the process with a background of conservative therapy during the primary hospitalization, the decision was to omit the emergency surgical intervention, while during the repeated hospitalization, the status of the patient was already not permitting the arrangement of surgery.

The prophylaxis of the atrioesophageal fistula includes the optimization of the ablation procedure with adjusting the energy power and the duration of the intervention in the posterior wall of the left atrium, the monitoring of the esophagus temperature, the visualization of its position during the procedure, as well as teaching the patients on the early symptoms of complications, such as the chest discomfort, the dyspepsia or dysphagia, the chest pain and the body temperature increase [26, 27], however, despite the implementation of these measures, the cases of atrioesophageal fistula continue occurring, especially in the settings of extending the indications for ablation and with the increase in the number of conducted procedures [28].

During the last 5 years (2019–2024), the PubMed and the Google Scholar data bases (Supplement 1) [29–35] have published not less than 20 descriptions of clinical cases of atrioesophageal fistula, developing after the radiofrequency catheter ablation due to atrial fibrillations. The majority of reports contain single cases, less frequently — small series of two patients. The age of the patients was described as ranging from 42 to 67 years, with men prevailing. The time from the procedure to the development of symptoms varied from 14 to 42 days. The most frequent clinical manifestations were fever, dysphagia, chest pain and acute neurological symptoms, including strokes caused by air or bacterial embolism. The diagnosis was most frequently set using the chest CT with oral contrasting, less frequently — during the esophagoscopy and using the indirect echocardiography signs [8, 35–37]. The mortality in the published cases remained high, most commonly due to the late diagnostics, with the debut of acute stroke and/or after the attempts of conservative therapy. In cases when the endoscopic stenting of the esophagus and/or the surgical intervention were conducted (especially within 24–48 hours after setting the diagnosis), the survival was increasing [31–33]. In the case presented, an atrioesophageal fistula was diagnosed on day 18 after RFA, with the subsequent development of an atrioesophageal fistula on day 40; the patient exhibited a typical clinical presentation including fever and neurological disorders. Despite the timely diagnostics and the combined treatment, including the draining of the pericardium, the endoscopic intervention and the antibacterial therapy, the outcome was lethal. This emphasizes that the atrioesophageal fistula, even in the settings of early diagnostics and aggressive therapy, remains an extremely severe complication with high risk of unfavorable outcome, especially with the developing multiple embolisms and septic complications. Unlike some of the published cases with successful surgical treatment, in our observation, the severity of the status and the rapid progression of neurological disorders did not allow for arranging the radical intervention, which, probably, affected the outcome (see Supplement 1).

CONCLUSION

Atrioesophageal fistula remains a rare but extremely dangerous complication of catheter ablation for atrial fibrillations, associated with high mortality rates. The presented clinical case demonstrates the typical clinical signs of atrioesophageal fistula with the development of fever, neurological disorders and signs of mediastinitis on day 18 after the RF ablation. Despite the timely diagnostics and the combined treatment that included the draining of the pericardium, the endoscopic intervention and the intensive antibacterial therapy, the outcome was lethal, which emphasizes the aggressive course of this complication and the limited possibilities of conservative approach.

The analysis of scientific research works published during the last 5 years confirms that early surgical intervention remains the most effective strategy, allowing for decreasing the mortality. Taking into consideration the extended indications for radiofrequency catheter ablation for atrial fibrillations and the increase in the number of conducted procedures, high clinical awareness is needed, along with improving the preventive measures and developing the standards for managing the patients with suspected atrioesophageal fistula.

ADDITIONAL INFORMATION

Supplement 1. Summarized characteristics of the published cases of atrioesophageal fistula after catheter ablation (2019–2024).

doi: 10.17816/clinpract695545-4392445

Author contributions: V.V. Gaskin, conceptualization, visualization, data curation, writing–original draft, writing–review & editing; A.A. Gaskina, conceptualization, formal analysis, data curation, writing–original draft, writing–review & editing; A.G. Masri, conceptualization, visualization, data curation, writing–review & editing; V.A. Nechaev, conceptualization, visualization, data curation, writing–review & editing; A.E. Markarov, conceptualization, writing–review & editing. Thereby, all authors provided approval of the version to be published and agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Consent for publication: The authors have obtained written informed consent from the patient’s representatives for the publication of personal data in a scientific journal, including its electronic version (date of signing 2025 Feb 20). The scope of the data to be published was agreed upon with the patient’s relatives.

Funding sources: The study had no sponsorship.

Disclosure of interests: The authors declare that they have no competing interests.

Statement of originality: The authors did not use previously published information (text, illustrations, data) while conducting this work.

Data availability statement: The editorial policy regarding data sharing does not apply to this work, data can be published as open access.

Generative AI: Generative AI technologies were not used for this article creation.

About the authors

Vladislav V. Gaskin

City Clinical Hospital named after F.I. Inozemtsev

Author for correspondence.
Email: drgaskinv@gmail.com
ORCID iD: 0000-0003-3161-9036
SPIN-code: 3136-6737

MD

Russian Federation, Moscow

Anna A. Gaskina

City Clinical Hospital named after A.K. Eramishantsev

Email: drgaskina@gmail.com
ORCID iD: 0000-0001-6973-4238
SPIN-code: 6323-5496

MD, PhD

Russian Federation, Moscow

Amir G. Masri

City Clinical Hospital named after F.I. Inozemtsev

Email: amir.masri@yandex.ru
ORCID iD: 0000-0001-6294-1285
SPIN-code: 5357-1487

MD

Russian Federation, Moscow

Valentin A. Nеchaev

City Clinical Hospital named after S.S. Yudin

Email: dfkz2005@gmail.com
ORCID iD: 0000-0002-6716-5593
SPIN-code: 2527-0130

MD, PhD

Russian Federation, Moscow

Arnold E. Markarov

City Clinical Hospital named after F.I. Inozemtsev

Email: markarnold@mail.ru
ORCID iD: 0000-0002-0392-8280
SPIN-code: 8919-9645

MD, PhD

Russian Federation, Moscow

References

Supplementary files