Luminal Esophageal Temperature Research Articles

High-Resolution Infrared Thermal Imaging of the Esophagus During Atrial Fibrillation Ablation as a Predictor of Endoscopically Detected Thermal Lesions: Results From the HEAT-AF Study.

Endoscopically detected thermal esophageal lesions (EDEL) after ablation of atrial fibrillation may be precursors of atrioesophageal fistula and esophageal luminal temperature monitoring has previously failed to decrease thermal damage. Sixty-three patients undergoing their first pulmonary vein isolation using radiofrequency point-by-point catheter ablation were prospectively included in the HEAT-AF study (High-Resolution Esophageal Assessment of Esophageal Temperature During Atrial Fibrillation Ablation) and esophageal temperatures were continuously monitored using a novel infrared thermography system (IRTS). Peak esophageal temperature (Tpeak) was correlated to postablation endoscopy results characterizing patients as EDEL positive or negative. Twelve patients had EDEL (19%). Comparing EDEL positive to negative patients, Tpeak was significantly higher (56.3±4.6°C versus 45.7±5.5°C, P<0.0001). Logistic regression analysis demonstrated Tpeak was a statistically significant predictor ( P=0.0008) of EDEL and yielded an odds ratio of 1.52; 95% CI, (1.24-2.05). Receiver operator curve analysis demonstrated Tpeak as a highly accurate binary classifier with an area under the curve of 93%. For the first time esophageal temperature monitoring using a high resolution, high-fidelity IRTS allowed accurate prediction of postablation EDEL suggesting that Tpeak alone is an excellent binary classifier of patients at risk of EDEL. The logistic regression model and associated receiver operator curve will aid in the selection of optimal temperature thresholds in future prospective studies.

Esophageal Deviation During AtrialFibrillation Ablation: Clinical Experience With a Dedicated EsophagealBalloonRetractor.

The goal of this study was to determine the safety and feasibility of a novel esophageal balloon retractor (DV8) for MED during PVI. The authors previously showed that mechanical esophageal deviation (MED) is feasible using an off-the-shelf metal stylet to allow uninterrupted ablation along the posterior left atrium during pulmonary vein isolation (PVI). Although it is an attractive strategy to avoid esophageal thermal injury, this technique was hampered by both the propensity for oropharyngeal trauma from the stiff stylet and the limited lateral esophageal displacement. In 200 consecutive patients undergoing atrial fibrillation ablation, the DV8 balloon retractor was used for MED; contrast was instilled into the esophagus to accurately delineate the trailing esophageal edge. Deviation was performed to maximize the distance from the trailing esophageal edge to the closest point of the ablation line (MEDEffective) and correlated to occurrences of luminal esophageal temperature elevation. In patients undergoing MED during a first-ever PVI of 304 vein pairs, the MEDEffective during right and left PVI were 21.2 ± 8.7 mm and 15.5 ± 6.8 mm, respectively. Deviation of at least 5 mm of MEDEffective was achievable in 97.7%. Luminal esophageal temperature increases universally occurred (100%) at MEDEffective<5 mm, less often (28%) at MEDEffective 5 to 20 mm, and rarely (1.9%) at MEDEffective >20 mm. There were no esophageal complications, but 2patientsexperienced oropharyngeal bleeding due to trauma related to device placement. MED with the balloon retractor safely moved the esophagus away from the site of energy delivery during atrial fibrillation ablation.

Feasibility, safety, and efficacy of a novel preshaped nitinol esophageal deviator to successfully deflect the esophagus and ablate left atrium without esophageal temperature rise during atrial fibrillation ablation: The DEFLECT GUT study

Esophageal thermal injury is a feared complication of radiofrequency ablation for atrial fibrillation (AF). Rise in luminal esophageal temperature (LET) limits the ability to deliver radiofrequency energy on the posterior wall of the left atrium. The purpose of this study was to evaluate the feasibility, safety, and efficacy of a mechanical esophageal deviation (ED) tool during AF ablation. We evaluated 687 patients who underwent radiofrequency ablation for AF. In 209 patients, the EsoSure (Northeast Scientific) was used to deflect the esophagus away from the ablation site. Propensity score matching was performed to obtain 180 patients each in the ED and non-ED arms. ED was used for LET rise seen in 61.7% of patients (111/180) and was used if the esophagus was in the line of ablation on fluoroscopy in 38.3% of patients (69/180). Mean deviation of trailing edge of esophagus with EsoSure was 2.45 ± 0.9 cm (range 1-4.5). LET rise >1°C was significantly lower in the ED than non-ED group (3% vs 79.4%; P<.001). Mean LET rise was also lower in the ED arm (ED 0.34 ± 0.59 vs non-ED 1.66 ± 0.54; P <.001). Intraprocedural success of pulmonary vein antral isolation, was slightly improved in the ED arm than in the non-ED arm without statistical significance. AF recurrence was lower in the ED arm at 3-month, 6-month, and 1-year follow-up than in the non-ED arm. No ED-related complications were noted. Mechanical displacement of the esophagus with EsoSure seems to be feasible, safe, and efficacious in enabling adequate radiofrequency energy delivery to the posterior wall of the left atrium without significant LET rise and obvious clinical signs of esophageal injury.

Abstract 20927: Use of a Novel Pre-Shaped Nitinol Esophageal Deviator (EsoSure®) to Successfully Ablate the Left Atrium Without Esophageal Temperature Rise During Atrial Fibrillation Ablation: The DEFLECT GUT Study

Background: Esophageal injury is a feared complication of atrial fibrillation (AF) ablation. Esophageal temperature monitoring has been used as a surrogate marker for potential esophageal thermal injury. Often times, rise in esophageal temperature during radiofrequency ablation (RFA) for AF limits the ability to deliver RF energy. Objective: The aim of this study was to evaluate the safety and efficacy of the EsoSure® (Northeast Scientific, Inc., Waterbury, CT), a mechanical esophageal deviation tool, during RFA for AF. Methods: In this prospective observational series, we evaluated 135 consecutive patients from 4 centers in whom luminal esophageal temperature (LET) rise or likely rise was limiting RFA lesion delivery on the posterior wall of the LA. EsoSure® was used to deflect the esophagus away from the ablation site in the LA. Light Barium was used to visualize and confirm esophageal displacement in all patients. Baseline demographics, procedural variables and complication rates were collected and evaluated. Patients were followed up to 3 months for clinical signs and symptoms of esophageal injury. Results: The mean age of our sample was 64 ± 10 years and 77 (57%) patients were males. Mean CHA2DS2-VASc score was 2.72 ± 1 and 97 (74 %) patients had paroxysmal AF. The mean deviation of the trailing edge of the esophagus with EsoSure® was 2.6 ± 1 cm (range: 0.8 - 4.5 cm). Successful intra-procedural end point, defined as successful pulmonary vein isolation, was achieved in 100% of patients. Among the 96 (71%) patients in whom EsoSure® was used after an increase in LET, the mean peak rise of LET was 1.3 ± 0.2° C prior to the EsoSure® use and 0.2 ± 0.1° C after the EsoSure® use (p&lt;0.001). There were no complications related to the EsoSure® use through 3-month follow-up. No symptoms suggestive of esophageal injury were noted related to AF ablation. Conclusions: Mechanical displacement of the esophagus with EsoSure® device appears to be safe and efficacious in enabling adequate RF energy delivery to the posterior wall of the LA during RFA for AF without significant luminal temperature rise and obvious clinical signs or symptoms of esophageal injury up to 3 months of follow up.

The Extent of Mechanical Esophageal Deviation to Avoid Esophageal HeatingDuring Catheter Ablation ofAtrialFibrillation.

This study sought to determine the extent of lateral esophageal displacement required during mechanical esophageal deviation (MED) and to eliminate luminal esophageal temperature elevation (LETElev) during pulmonary vein(PV) isolation. MED is a conceptually attractive strategy of minimizing esophageal injury while allowing uninterrupted energy delivery along the posterior left atrium during PV isolation. MED was performed using a malleable metal stylet within a plastic tube placed within the esophagus. Barium was instilled to characterize the trailing esophageal edge. For each MED attempt, the MEDEffective, defined as the distancefrom the trailing esophageal edge-to-ablation line, was correlated to occurrences of LETElev. In 114 consecutive patients/221 PV pairs undergoing MED (age 62.1 ± 11 years, 75% men, 62%/38% paroxysmal/persistent AF), esophageal stretching invariably occurred such that the esophageal edge trailed behind the plastic tube. MEDEffective distances of 0 mm to 10 mm, 10 mm to 15 mm, 15 mm to 20 mm or >20 mm were achieved in 60 (27.1%), 64 (29%), 48 (21.7%), and 49 (22.2%) attempts, respectively. Overall, LET elevation >38°C occurred in 81of 221 (36.7%) PV pairs. The incidence of LETElev among the 4 groups was 73.3%, 35.9%, 25%, and 4.1%, respectively. MEDEffective distances were 9.1 ± 6.5 mm and 18 ± 7.6 mm in patients with and without LETElev, respectively (p<0.0001). Three patients (2.6%) experienced clinically significant MED-related trauma, albeit only with a stiffer stylet. Mechanical esophageal deviation >20 mm from the PV ablation line prevents significant esophageal heating during PV isolation, but this level of displacement was difficult to safely achieve with this off-the-shelf mechanical stylet approach.

The relationship between oesophageal heating during left atrial posterior wall ablation and the durability of pulmonary vein isolation.

During ablation of the posterior wall (PW), luminal oesophageal temperature elevation (OTE) prompts attenuation of radiofrequency (RF) energy delivery to minimize oesophageal injury. This strategy on lesion efficacy is unknown. The goal of this study was to analyse the relationship between OTE and pulmonary vein reconnection (PVR). During the index antral pulmonary vein (PV) isolation procedure with an irrigated RF ablation catheter, OTE was detected with a multisensor oesophageal temperature probe. Posterior wall ablation did not exceed 25 W and was terminated when the temperature was ≥38.5°C. Patients undergoing redo procedures (n = 142) were studied for PW sites of PVR along 4 segments: left and right superior, and left and right inferior. Pulmonary vein reconnections had occurred in 51 of the 142 patients (36%), in 58 of 284 PV pairs (20%). Among these 58 reconnected pairs, 83% (n = 48) were along the PW. Oesophageal temperature elevation had occurred in 30 patients (59%). No difference in characteristics was seen between the patients with OTE (n = 30) and those without (n = 21). For superior segments, there was no interaction between the presence or absence of OTE and PVR. For inferior segments, there were more PVRs in the group with OTE: for the right-inferior segment, the PVR rate was 72% for OTE cases vs. 42% without (P = 0.04), and for the left-inferior segment, the PVR rate was 44% for OTE cases vs. 22.9% without (P = 0.12). Pulmonary vein reconnections are predominantly posteriorly located. Along the right- and left-inferior PW segments, there was an association with elevated oesophageal temperature during the index procedure.

Thermal Field in Cryoablation Procedures for Pulmonary Veins Isolation: Importance of Esophageal Temperature Monitoring.

Cryoablation procedures for pulmonary veins isolation have proved to be a successful treatment of atrial fibrillation, but exposure of surrounding organs to excessively low temperatures is potentially dangerous. Hence the importance of monitoring esophageal temperature and at the same time predicting the thermal field induced by the procedure, so to provide clinicians with a valuable tool to take critical decisions. We formulate a mathematical model for computing the temperature in the relevant region and we use numerical simulations to interpret recorded clinical data. The temperature at the outer esophageal surface can be much lower than the luminal one. Observing the esophageal lumen cooling rate at the early stage of the procedure it is possible to forecast whether temperature is bound to reach dangerous values; the same quantity has a correlation with the steepness of the transesophageal thermal gradient. Monitoring the time evolution of luminal esophageal temperature is of fundamental importance not only to realize but also to predict well in advance critical developments of the procedure.

Esophageal Temperature Monitoring During Radiofrequency Ablation of Atrial Fibrillation: A Meta-Analysis.

Objective: Atrio-esophageal fistula is an infrequent but devastating complication of catheter-based ablation of atrial fibrillation (AF). Thermal esophageal injury may be the precursor of atrio-esophageal fistula. Here, we evaluated the role of esophageal temperature monitoring in preventing thermal esophageal injury during pulmonary vein isolation for AF with radiofrequency energy. Methods: In this meta-analysis, we searched the PubMed, Cochrane, Scopus, Embase, and Refworks databases for all published studies from January 2004 to June 2016 to evaluate the role of esophageal temperature monitoring. We searched for terms esophageal temperature monitoring, AF, radiofrequency ablation, atrio-esophageal fistula, and thermal esophageal injury. We included studies comparing luminal esophageal temperature (LET) monitoring with no LET monitoring during radiofrequency ablation of AF. We excluded studies in which post-ablation esophagogastroduodenoscopy (EGD) was not performed to identify esophageal thermal injuries. To perform the meta-analysis, we used Review Manager statistical software and a fixed-effects modeling to derive the outcomes. Given significant heterogeneity between the studies, we used meta-regression analysis to adjust for age and sex. Results: We identified 4 non-randomized controlled trials that met our search criteria and included a total of 411 patients (n=235 in the LET monitoring group; n=176 in the no LET monitoring group) in the analysis. There were 21 (8.9%) patients with thermal esophageal injury in the LET monitoring group and 12 (6.8%) in the no LET monitoring group. The pooled odds ratio was 0.66 (0.23-1.89), indicating no statistically significant differences between the 2 groups with regard to esophageal injury. Because of the small sample size and the non-randomized nature of the trials, we observed significant heterogeneity in outcomes among the trials. Conclusion: The role of esophageal temperature monitoring in reducing the risk of esophageal thermal lesions during pulmonary vein isolation for AF has not been established, and more studies including randomized controlled trials are needed to assess its true impact.

Incidence of asymptomatic oesophageal lesions after atrial fibrillation ablation using an oesophageal temperature probe with insulated thermocouples: a comparative controlled study.

Oesophageal probes to monitor luminal oesophageal temperature (LET) during atrial fibrillation (AF) catheter ablation have been proposed, but their effects remain unclear. Aim of this study is to evaluate the effects of an oesophageal temperature probe with insulated thermocouples. Patients with symptomatic, drug-refractory paroxysmal or persistent AF who underwent left atrial radiofrequency (RF) catheter ablation were prospectively enrolled. Patients were ablated using a single-tip RF contact force ablation catheter. An intraluminal oesophageal temperature probe was used in Group 1. In Group 2, patients were ablated without LET monitoring. Assessment of asymptomatic endoscopically detected oesophageal lesions (EDEL) was performed by oesophagogastroduodenoscopy (EGD) in all patients. Eighty patients (mean age 63.7 ± 10.7 years; men 56%) with symptomatic, drug-refractory paroxysmal (n = 28; 35%) or persistent AF were included. Group 1 and Group 2 patients (n = 40 in each group) were comparable in regard to baseline characteristics, but RF duration on the posterior wall was significantly shorter in Group 1 patients. Overall, seven patients (8.8%) developed EDEL (four ulcerations, three erythema). The incidence of EDEL in Group 1 and Group 2 patients was comparable (7.5 vs. 10%, P = 1.0). No major adverse events were reported in both groups. According to these preliminary results, the use of oesophageal temperature probes with insulated thermocouples seems to be feasible in patients undergoing AF RF catheter ablation. The incidence of post-procedural EDEL when using a cut-off of 39°C is comparable to the incidence of EDEL without using a temperature probe.

Difference in thermodynamics between two types of esophageal temperature probes: Insights from an experimental study

Luminal esophageal temperature monitoring is performed with a variety of temperature probes, but little is known about the relationship between the structure of a given probe and its thermodynamic characteristics. The purpose of this study was to evaluate the difference in thermodynamics between a 9Fr standard esophageal probe and an 18Fr esophageal stethoscope. In the experimental setting, each probe was submerged in a constant temperature water bath maintained at 42°C; in the patient setting, we monitored the temperature with both probes at the same time. The time constant of the stethoscope was higher than that of the probe (33.5 vs 8.3 s). Compared to the probe, the mean temperature measured by the stethoscope at 10 seconds was significantly lower (22.5°C ± 0.4°C vs 33.5°C ± 0.3°C, P<.0001), whereas the time to reach the peak temperature was significantly longer (132.6 ± 5.9 s vs 38.8 ± 1.0 s, P<.0001). Even in the ablation cases we observed that when the esophageal probe reached a peak temperature of 39.6°C ± 0.3°C, the esophageal stethoscope still displayed a temperature of 37.3°C ± 0.2°C (a mean of 2.39°C ± 0.3°C lower, P<.0001), showing a <0.5°C increase in temperature half of the times. The 18Fr esophageal stethoscope has a significantly slower time response compared to the 9Fr esophageal probe. In the clinical setting, this might result in a considerable underestimation of the luminal esophageal temperature with potentially fatal consequences.

Safety And Necessity Of Thermal Esophageal Probes During Radiofrequency Ablation For The Treatment Of Atrial Fibrillation.

Radiofrequency ablation is extensively used to achieve pulmonary veins isolation for the cure of atrial fibrillation. Luminal esophageal temperature can be monitored by means of suitable probes to prevent the onset of lesions. To compute the thermal field generated by the ablation, to investigate the interaction between the electromagnetic field and the probe sensors, and to provide a safe interpretation of the temperature detected by the probe, supported by clinical data. A mathematical model is formulated and the thermal and electromagnetic fields are computed. Experiments have been performed to assess the the influence of the ablator on the probe sensors. Clinical data have been collected during RF isolation of pulmonary veins in patients with atrial fibrillation. The direct interaction between the radiofrequency source and the probe sensors is found to be negligible. Numerical simulations show that the outer esophageal wall can be much warmer than the lumen. Theoretical heating curves are compared with the clinical data selecting the maximal slope as the reference quantity. The clinical values range between 0.01°C/s and 0.15°C/s agree with the computed predictions and demonstrate that reducing the esophagus-atrium distance by 1mm causes a slope increase of 0.06°C/s. The use of esophageal thermal probes is absolutely safe and necessary in order to prevent the occurrence of thermal lesions. The model is reliable, and describes effectively the generated thermal field. The external esophageal temperature can be considerably higher than the luminal one.

Is It Necessary to Achieve a Complete Box Isolation in the Case of Frequent Esophageal Temperature Rises? Feasibility of Shifting to a Partial Box Isolation Strategy for Patients With Non-Paroxysmal Atrial Fibrillation.

There are some cases with frequent luminal esophageal temperature (LET) rises despite titrating the radiofrequency energy while creating a linear lesion for the Box isolation of atrial fibrillation (AF). Little is known about the feasibility of redesigning the ablation lines for a modified Box isolation strategy to prevent fatal esophageal injury in those cases. Two hundred and seventeen patients who underwent a Box isolation of non-paroxysmal AF were evaluated. We divided them into 2 groups, patients in whom a box lesion set of the entire posterior left atrium had been achieved (complete Box isolation [CBI]; n = 157) and those in whom 2 additional peri-esophageal vertical lines were created at both the right and left ends of the esophagus, and those areas were left with an incomplete isolation when frequent rapid LET rises above 39.0 °C were observed while creating the floor line (partial Box isolation [PBI]; n = 60). During 20.1 ± 13.9 months of follow-up, the arrhythmia-free rates were 54.1% in the CBI group versus 48.3% in the PBI group (P = 0.62). In the second session, a complete Box isolation was highly achieved even in the PBI group (94.3% vs. 83.3%, respectively; P = 0.17) and after 2 procedures, the arrhythmia-free rates increased to 75.2% vs. 68.3%, respectively (P = 0.34). There was no symptomatic esophageal injury in the PBI group. In the case of frequent LET rises while creating the linear lesions for the Box isolation strategy for non-paroxysmal AF, shifting to the PBI strategy was feasible.

136-09: Improving safety of esophageal thermal probes

Purpose: Monitoring luminal esophageal temperature (LET) during RF or cryo-ablation procedures for pulmonary veins isolation is highly desirable to prevent the onset of esophageal thermal lesions (ETLs). Nevertheless it is not universally accepted that the use of esophageal thermal probes is completely safe. In some cases occurrence of ETLs during RF ablation has been (a bit hastily) attributed to the presence of the probe metallic sensors, as if they were able to capture power from the electromagnetic field (the so-called antenna effect). Here we point out the main features for a correct and safe LET measurement. Method: LET measurement is safely achieved under the following conditions: fast thermal response (order 1 sec), precision (<0.5°C), limiting mechanical action to esophageal tissue, avoiding the antenna effect, staying far from dangerous temperatures (too high, or too low), inspecting the full portion of the esophagus next to the left atrium, and possibly predicting unfavorable thermal evolution at an early stage of the procedure. We refer about a new system accomplishing these goals. Summary of results: Our experimental and theoretical studies have allowed to design a new esophageal temperature acquisition system meeting all these requirements. In our opinion it is advisable not to use deflectable probes, since the esophagus is very sensitive to mechanical actions. Notwithstanding the several evidences that the RF field is so weak in the sensors region that the deposited power is absolutely negligible, some clinician is irreducibly refractory to the idea of using metallic sensors. For those physicians we has designed a probe with electrically insulated sensors. A full covering of the interested zone (at least 4cm) is obtained by increasing the number of electrodes. It is very important that the probe is deployed correctly and for this reason we have developed a system which automatically detects if the probe position is not ideal, missing the maximal (minimal) temperature. Moreover, it is possible to understand the presence of a real ETL risk examining the temperature rate of change soon after RF or cryo application. The new system is able to compute that slope and provide an early alarm. Conclusion: The new system to detect LET and elaborate the data meets all requirements to make the measurement safe and effective, signaling the attainment of threshold temperatures, the probe displacement from the ideal position, and excessive values of the temperature rate of change, thus predicting unfavorable conditions for the procedure. Concerning the antenna effect, one of the arguments against it is the following: the sensors react to RF delivery with some delay (the heat transfer time), while they should be immediately "lighted up" if they were somehow coupled to the field. Similarly, LET keeps increasing for a while after RF switching off.

15. Measurement of esophageal temperature at two separate sites during pulmonary vein ablation

Pulmonary vein ablation (PVA) has been used to treat persistent supraventricular arrhythmias, in which a cardiologist first isolates and then thermally ablates the source of the arrhythmia1. Since the esophagus is in close proximity to the left atrium, heat induced injury to the esophagus may occur2. Although the incidence is low, the mortality rate is high. Luminal esophageal temperature (ET) monitoring is one of the most effective measures to minimize the risk of injury3. In this retrospective study, we elected to analyze temperature changes during PVA at two different temperature monitoring sites in the esophagus. The anesthetic technique was standardized and utilized general anesthesia, endotracheal intubation and an arterial line. ET monitors were placed at two mid-atrial locations, ET1 and ET2 separated by 1–1.5 inches in the esophagus, as determined by cardiologist using fluoroscopy. Temperatures at both ET1 and ET2 locations were recorded simultaneously when radio-frequency ablation was performed at different left atrial sites. The peak ET was recorded at each location. In particular, the increase over baseline ET and the difference between ET1 and ET2, were noted. Twenty five patients were studied. Ablation sites in the left atrium included the anterior, posterior, inferior regions and the pulmonary veins. The most significant increases in temperature were seen during ablation of the posterior left atrium ranging from 0.1 to 4.0 degrees. However, in 20 out of 25 patients, measurements of ET1 ≠ ET2. The absolute value of difference of temperature between ET1 and ET2 ranged from 0.4 to 3.8, with a mean of 1.3 and a standard deviation of 1.1. These findings suggest that measurement of temperature at two separate esophageal locations is more sensitive that one location in detecting temperature increases during PVA. The ablating electrode during PVA moves from different areas within the left atrium, and therefore, a wide area of temperature measurement is needed for more accurate monitoring. Furthermore, the most significant increases in temperature occurred when ablation performed in the posterior left atrium, adjacent to the esophagus. The implications of these observations suggest that one location of temperature measurement may not be accurate enough in detecting a “true” esophageal temperature. Further studies are needed to verify these findings in a prospective study and to ascertain whether this has any patient safety ramifications for preventing esophageal injury.

Evaluation of periesophageal nerve injury after pulmonary vein isolation using the 13C-acetate breath test

BackgroundPulmonary vein isolation (PVI) has become an important option for treating patients with atrial fibrillation (AF). Periesophageal nerve (PEN) injury after PVI causes pyloric spasms and gastric hypomotility. This study aimed to clarify the impact of PVI on gastric motility and assess the prevalence of gastric hypomotility after PVI. MethodsThirty consecutive patients with AF underwent PVI under luminal esophageal temperature (LET) monitoring. The 13C-acetate breath test was conducted before and after the procedure for all patients (PVI group). Gastric emptying was evaluated using the time to peak concentration of 13CO2 (Tmax). This test was also conducted in another 20 patients who underwent catheter ablation procedures other than PVI (control group). ResultsThe number of patients with abnormal Tmax (≥75min) increased from seven (23%) to 13 (43%) and from three (15%) to five (25%) after the procedure in the PVI group and control group, respectively. The mean Tmax was longer after PVI than before PVI (64±14min vs. 57±15min, p=0.006), whereas there was no significant difference before and after the procedure in the control group. However, no significant difference in ΔTmax was observed between the two groups (p=0.27). No patients suffered from symptomatic gastric hypomotility. ConclusionsAsymptomatic gastric hypomotility occurred more often after PVI. However, the average impact of PVI on gastric motility was minimal.

Higher incidence of esophageal lesions after ablation of atrial fibrillation related to the use of esophageal temperature probes.

Endoscopically detected esophageal lesions (EDELs) have been identified in apparently asymptomatic patients after catheter ablation of atrial fibrillation (AF). The use of esophageal probes to monitor luminal esophageal temperature (LET) during catheter ablation to protect esophageal damage is currently controversial. The purpose of this study was to investigate the impact of the use of esophageal temperature probes during AF catheter ablation on the incidence of EDELs. Eighty consecutive patients (mean age 63.8 ± 11.36 years; 68.8% men) with symptomatic, drug-refractory paroxysmal (n = 52, 65%) or persistent AF who underwent left atrial radiofrequency catheter ablation were prospectively enrolled. Posterior wall ablation was power limited (≤25 W). In the first 40 patients, LET was monitored continuously (group A), whereas no esophageal temperature probe was used in group B (n = 40 patients). Assessment of EDEL was performed by endoscopy within 2 days after radiofrequency catheter ablation. Overall, 13 patients (16%) developed EDELs after AF ablation. The incidence of EDELs was significantly higher in group A than group B (30% vs 2.5%, P < .01). Within group A, patients who developed EDEL had higher maximal LET during AF ablation than patients without EDEL (40.97 ± 0.92°C vs 40.14 ± 1.1°C, P = .02). Multivariable logistic regression analysis revealed the use of an esophageal temperature probe as the only independent predictor for the development of EDEL (odds ratio 16.7, P < .01). The use of esophageal temperature probes in the setting of AF catheter ablation per se appears to be a risk factor for the development of EDEL.

Prevalence of Esophageal Ulceration After Atrial Fibrillation Ablation with the Hot Balloon Ablation Catheter: What is the Value of Esophageal Cooling?

Little is known about luminal esophageal temperature (LET) monitoring during catheter ablation for atrial fibrillation (AF) using the radiofrequency hot balloon (RHB) technology. The aim of this study is to investigate the impact of the use of a unique esophageal cooling method during RHB ablation. In this observational study, 318 consecutive patients (231 men; mean age, 63 ± 9 years) with symptomatic, drug-refractory, paroxysmal (n = 183) or persistent (n = 135) AF underwent RHB ablation with LET monitoring followed by a postprocedural, nonsymptom-driven esophageal endoscopy within 3 days of the ablation procedure. The patients have been divided into 3 groups. The first 22 patients treated are in Group A (n = 22) and had only LET monitoring without cooling of the esophagus. In Groups B (n = 128) and C (n = 168), patients had LET monitoring with cooling of the esophagus when the LET exceeded 43 °C and 39 °C, by infusion of cooled saline mixed with Gastrographin or Iopamidol, respectively. Group A had a higher risk of esophageal ulceration among the 3 groups (P < 0.0001). Saline infusion cooling initiated when the LET exceeded 43 °C (Group B) was not as safe as saline infusion cooling initiated when the LET exceeded 39 °C (Group C), demonstrated by the Group C minimum ulceration score and LET measurements while ablating the left superior pulmonary vein (LSPV) and left inferior pulmonary vein (LIPV) (P < 0.0001). Cooling the esophagus by a mix of Iopamidol and saline infusion when the LET exceeds 39 °C during RHB ablation may decrease the incidence and severity of esophageal thermal injury.

Luminal Esophageal Temperature Monitoring for the Prevention of Esophageal Injury During Left Atrial Ablation: LET It Be?

Luminal Esophageal Temperature Monitoring for the Prevention of Esophageal Injury During Left Atrial Ablation: LET It Be?

Benefit to Decrease Esophageal Damage using an Ablation Catheter with Increased Irrigation Channels for Pulmonary Vein Isolation

An ablation catheter has been developed with six additional irrigation channels at the proximal end of the ablating electrode. We investigated the potential improvement of esophageal damage when the number of irrigation channels of the ablation catheter was increased during pulmonary vein isolation (PVI). This study included a total of 296 consecutive patients with atrial fibrillation. One hundred forty-eight patients were randomly assigned to receive PVI using an ablation catheter with six distal irrigation channels (6C) and 148 patients to receive PVI using an ablation catheter with 12 distal irrigation channels (12C). The luminal esophageal temperature (LET) was monitored in all patients. A total of 639 radiofrequency energy applications (in 225 out of 296 patients) reached the cut-off temperature. The time for the LET to reach the cut-off temperature was shorter for the 6C than the 12C group, and the 6C group had a higher T max of the LET than the 12C group. Some patients experienced a transient drop in the LET (TDLET) just before the delivery of the energy. The site that caused a TDLET before the energy delivery always reached the cut-off temperature. TDLET was more frequent in the 6C group than in the 12C group. The LET only showed a small difference between the 6C and 12C groups. In contrast, there may be a lower risk of esophageal injury with the 6C than the 12C if we use TDLET.

Luminal esophageal temperature predicts esophageal lesions after second-generation cryoballoon pulmonary vein isolation

The novel second-generation cryoballoon (CB) facilitates pulmonary vein isolation (PVI) by improved surface cooling. The impact of this redesign on collateral damage is unknown. To investigate the incidence of esophageal lesions after PVI using the second-generation CB and the role of luminal esophageal temperature (LET) measurement as a predictor of lesion formation. Thirty-two consecutive patients underwent PVI using the second-generation 28 mm CB. Target application time was 2 × 240 seconds. Ninety-two percent of the PVs were isolated after 1 cryoenergy application. Complete PVI was achieved in all patients. LET with 3 thermocouples was continuously measured during cryoenergy application. Freezing was interrupted only if weakening/loss of phrenic nerve function or low LET (<5 °C) was observed. The lowest measured LET was-12 °C (despite cryoapplication interruption). Postprocedural gastroesophagoscopy was performed after 1-3 days in all patients and showed lesions in 6 of 32 (19%) patients. A minimum LET of≤12 °C predicted esophageal lesions with 100% sensitivity and 92% specificity (area under the receiver-operator characteristic curve 0.97; 95% CI 0.93-1.02; P = .001). Persistent phrenic nerve palsy occurred in 2 (6%) patients during ablation at the right inferior pulmonary vein. Repeat gastroesophagoscopy confirmed healing of lesions after 16 ± 14 days. Second-generation 28 mm CB PVI is associated with significant esophageal cooling, resulting in lesion formation in 19% of the patients. LET measurement accurately predicts lesion formation and may enhance the safety of the novel device.