Objective: To determine trends in real-world utilization and in-hospital adverse events from Watchman implantation since its approval by the Food and Drug Administration in 2015. Background: The risk of embolic stroke caused by atrial fibrillation is reduced by oral anticoagulants, but not all patients can tolerate long-term anticoagulation. Left atrial appendage occlusion with the Watchman device has emerged as an alternative therapy. Methods: This was a retrospective cohort study utilizing data from National Inpatient Sample for calendar years 2015-2017. The outcomes assessed in this study were associated complications, in-hospital mortality, and resource utilization trends after Watchman implantation. Trends analysis were performed using analysis of variance. Multivariable adjusted logistic regression analysis was performed to determine predictors of mortality. Results: A total of 17,700 patients underwent Watchman implantation during the study period. There was a significantly increased trend in the number of Watchman procedures performed over the study years (from 1,195 in 2015 to 11,165 devices in 2017, p < 0.01). A significant decline in the rate of complications (from 26.4% in 2015 to 7.9% in 2017, p < 0.01) and inpatient mortality (from 1.3% in 2015 to 0.1% in 2017, p < 0.01) were noted. Predictors of in-hospital mortality included a higher CHA₂DS₂-VASc score (OR 2.61 per 1-point increase, 95% CI 1.91-3.57), chronic blood loss anemia (OR 3.63, 95% CI 1.37-9.61) and coagulopathy (OR 4.90, 95% CI 2.32-10.35). Conclusion: In contemporary United States clinical practice, Watchman utilization has increased significantly since approval in 2015, while complications and in-patient mortality have declined.

A document by David Sanders . Click on the document to view its contents.

The exponential rise in the incidence of peri-mitral flutter has paralleled the increasing use of more extensive atrial substrate ablation for atrial fibrillation (AF). Given the relative paucity of randomised evidence to support its role in AF management, mitral isthmus ablation should largely be reserved for patients with peri-mitral flutter. Catheter ablation for peri-mitral flutter is challenging due to complex anatomic relationships. The aim of this report is to review the anatomic considerations and approaches to catheter ablation for peri-mitral flutter.

Very late recurrences after ablation of AVNRT have been reported. Age related alterations of nodal tissues caused by fibrous and fatty tissue infiltration and changes of the sympathovagal influence on the AV node, in turn altering AV nodal conduction and refractoriness, could set the stage for a previously not present substrate for AVNRT. Consequently, the occurrence of AVNRT many years after an ablation procedure may perhaps not always implicate a recurrence but instead an arrhythmia caused by a new substrate.

Abstract poster

Objective: The implantation depth and membranous septum (MS) length are established as the predictors of new-onset conduction disturbance (CD) after transcatheter aortic valve replacement (TAVR) for tricuspid aortic valve (TAV) stenosis. However, little is known about the predictors with bicuspid aortic valve (BAV). This study investigated the role of MS length and implantation depth in predicting CD following TAVR with a balloon-expandable valve in patients with BAV. Methods and results: This retrospective study analyzed 169 patients who underwent TAVR for BAV with balloon-expandable valve, and TAV cohort was established as a control group using propensity score (PS) matching. The primary endpoint was in-hospital new-onset CD (new-onset left bundle branch block or new permanent pacemaker implantation). New-onset CD developed in 37 patients (21.9%). Multivariate analysis revealed severe LVOT calcification (Odds ratio [OR]: 5.83, 95% confidence interval [CI]: 1.08 – 31.5, p = 0.0407) and implantation depth – MS length (OR: 1.30, 95% CI: 1.12 – 1.51, p = 0.0005) as the predictors of new-onset CD within BAV cohort. The matched comparison between BAV and TAV groups showed similar MS length (3.0 vs 3.2mm, p = 0.5307), but valves were implanted deeper in BAV than TAV group (3.9 vs 3.0mm, p < .0001). New-onset CD was more frequent in patients having BAV (22.3% vs 13.9%, p = 0.0458). Conclusion: The implantation depth - MS length, and severe LVOT calcification predicted new-onset CD following TAVR in BAV with balloon-expandable valve. High implantation technique could be considered to avoid new-onset CD in BAV anatomy.

Background: Increasing interest in physiological pacing has been countered with challenges such as accurate lead deployment and increasing pacing thresholds with His-bundle pacing (HBP). More recently, left bundle branch area pacing (LBBAP) has emerged as an alternative approach to physiologic pacing. Objective: To compare procedural outcomes and pacing parameters at follow-up during initial adoption of HBP and LBBAP at a single center. Methods: Retrospective review, from September 2016 to January 2020, identified the first 50 patients each who underwent successful HBP or LBBAP. Pacing parameters were then assessed at first follow-up after implantation and after approximately one year, evaluating for acceptable pacing parameters defined as sensing R-wave amplitude >5 mV, threshold <2.5 V @ 0.5 ms and impedance between 400 and 1200 Ohms. Results: The HBP group was younger with lower ejection fraction compared to LBBP (73.2±15.3 vs 78.2±9.2 years, p=0.047; 51.0±15.9% vs 57.0±13.1%, p = 0.044). Post-procedural QRS widths were similarly narrow (119.8±21.2 vs. 116.7±15.2ms; p = 0.443) in both groups. Significantly fewer patients with HBP met the outcome for acceptable pacing parameters at initial follow-up (56.0% vs 96.4%, p = 0.001) and most recent follow-up (60.7% vs 94.9%, p = <0.001; at 399±259 vs. 228±124 days, p = <0.001). More HBP patients required lead revision due to early battery depletion (0 vs 13.3%, at an average of 664 days). Conclusion: During initial adoption, as compared with LBBAP, HBP is associated with a significantly higher frequency of unacceptable pacing parameters, energy consumption, and lead revisions.

Is There Rule to the Chaos: Defining Stable Patterns in Atrial Fibrillation

Reply to “Additional Data Protection of the Esophagus During Catheter Ablation of Atrial Fibrillation”Mahmoud Houmsse, MD, and Emile G. Daoud, MDDepartment of Medicine, Division of Cardiology, Richard M. Ross Heart HospitalThe Ohio State University Medical Center, Columbus, OHRunning Title: Protection of EsophagusAddress for correspondence: Emile Daoud, MDDHLRI 473 W. 12th Avenue, Suite 200 Columbus, OH 43210-1252 Telephone: 877-478-2478 FAX : 614-293-5614E-Mail: emile.daoud@osumc.eduFunding: NoneDisclosure: Emile Daoud and The Ohio State University have equity ownership and serve as consultants to S4 Medical Corp, which is manufacturing the Esoultion esophageal retractor.Disclosure: Mahmoud Houmsse has no conflict of interestWe Thank Dr.Clark and Dr. Kulstad for their interest in our recent review manuscript “protection of the esophagus during catheter ablation of atrial fibrillation”We agree with Dr. Clark and Dr. Kulstad that utilization of luminal esophageal temperature (LET) monitoring during atrial fibrillation ablation is inadequate method to avoid esophageal injury. These have been reported in multiple studies that were referenced in our manuscript. The newer published studies regrading monitoring LET during atrial fibrillation ablation, which were reported by Dr. Clark and Dr. Kulstad, have been published during our manuscript publication process. Nevertheless, these studies that reported by Dr. Clark and Dr. Kulstad showed same conclusion of inadequate LET monitoring in preventing esophageal injury 1-3.Regarding active cooling, Dr. Clark and Dr. Kulstad reported recent published studies. First study small pilot study that showed active cooling is much more protective than manual liquid instillation4. The second pilot RCT that compared LET and active cooling showed same outcome like the IMPACT study that we reported in our manuscript 5,6.We agree with Dr. Clark and Kulstad, growing interest in the area of esophageal protection during atrial fibrillation ablation.We do believe, as we stated in the conclusion of our manuscript, that “a reliable method to protect the esophagus is of clinical value, but the ancillary value of reducing physician concern during AF ablation, reducing interruption to ablation work flow, perhaps enhancing AF ablation results and simplifying post procedure management of patient symptoms are also of high importance. Considering the ease of use, minimal side effects, and low costs associated with esophageal protection devices, these features offer compelling evidence for use of esophageal protection as routine care for AF ablation”.

A 30-year-old man with a structurally normal heart was referred to us with a 2-year history of recurrent episodes of rapid paroxysmal palpitations. A few episodes required hospitalization and were terminated with intravenous diltiazem. During electrophysiology (EP) study done twice before in other hospitals, the patient was diagnosed as typical atrioventricular nodal reentrant tachycardia (AVNRT) and underwent radiofrequency ablation of the slow pathway. However, the episodes recurred.  Because of the patient’s persistent symptoms, an EP study was performed again. Tachycardia was easily induced using atrial extrastimuli, ventricular extrastimuli and with rapid atrial pacing.

Introduction: Contact force (CF) catheters provide feedback confirming adequate tissue contact for optimal lesion size and minimal complications. CF ablation catheters have resulted in decreased procedure times and improved outcomes for ablation of atrial fibrillation in adults. There is limited data evaluating CF use for accessory pathway (AP) ablation or in pediatric patients. The aim of our study was to compare a cohort who underwent AP ablation with a CF catheter to historical controls, evaluating for differences in procedure times, number of lesions, and outcomes. Methods: A retrospective chart review of CF ablation cases at Children’s Wisconsin performed between June 2015 to April 2018 was compared to a historical control cohort of traditional radiofrequency (RF) ablations between June 2012 to June 2015. 43 patients with APs underwent 49 CF ablation procedures (18 males, 13.6 ± 3 years old) and a control cohort consisted of 77 procedures in 69 patients (38 males, 12.4 ± 4 years). Results: The groups did not differ significantly on procedure time (CF 2.01 ± 0.48 hr, control 1.53 ± 0.48 hr, p = 0.37), or total lesions administered (CF and control 7 ± 6 lesions, p = 0.89). CF cases showed a trend toward improvement in acute success (98% CF, 90% controls, p = 0.15) though with increased recurrence compared to controls (13% CF, 5% controls, p = 0.16), neither being statistically significant. Conclusion: Our study suggests that ablation outcomes using CF are comparable to traditional RF ablation in pediatric patients with APs.

Introduction: Prior to ablation, predicting the site of origin (SOO) of outflow tract ventricular arrhythmia (OTVA), can inform patient consent and facilitate appropriate procedural planning. We set out to determine if OTVA variability can accurately predict SOO. Methods: Consecutive patients with a clear SOO identified at OTVA ablation had their prior 24-hour ambulatory ECGs retrospectively analysed (derivation cohort). Percentage ventricular ectopic (VE) burden, hourly VE values, episodes of trigeminy/bigeminy, and the variability in these parameters were evaluated for their ability to distinguish right from left sided SOO. Effective parameters were then prospectively tested on a validation cohort of consecutive patients undergoing their first OTVA ablation. Results: High VE variability (coefficient of variation ≥ 0.7) and the presence of any hour with < 50 VE, were found to accurately predict RVOT SOO in a derivation cohort of 40 patients. In a validation cohort of 29 patients, the correct SOO was prospectively identified in 23/29 patients (79.3%) using CoV, and 26/29 patients (89.7%) using VE < 50. Including current ECG algorithms, VE < 50 had the highest Youden Index (78), the highest positive predictive value (95.0%) and the highest negative predictive value (77.8%). Conclusion: VE variability and the presence of a single hour where VE < 50 can be used to accurately predict SOO in patients with OTVA. Accuracy of these parameters compares favourably to existing ECG algorithms.

Ultrasound guided venous access Is important to minimize pneumothorax and unnecessary incisions in patients undergoing device implant.

We read with great interest the recent study by Rogers, et al. describing lesion formation with continuous versus intermittent radiofrequency ablation.1 The authors applied 50 (ex-vivo) or 10 (in-vivo) watts with either intermittent (15-seconds x4, 30-seconds x2, or 60-seconds x1) or continuous (1, 2, 3, or 5 minutes) radiofrequency applications and examined lesion size with each strategy. Continuous lesions resulted in significantly larger lesion size with possibly increased risk of steam pops at high power. In the ex-vivo model, they saw rapid lesion formation in the first minute of ablation with substantial drop-off in expansion of lesion size over time especially after 3 minutes (down to 0.35mm/min at 5 minutes), and suggest that there is only minimal incremental benefit of prolonging ablation lesion duration beyond 3 minutes in normal tissue.They have, however, appropriately recognized the limitation of their model which lacks significant fibrosis, limiting the generalizability of their findings to ablation in patients with scar. It is important to recognize that lesion formation in scar-related ventricular tachycardia (VT) is likely to differ dramatically compared to normal myocardial tissue. Barkargan, et al. have shown in an in-vivo porcine model of anterior myocardial infarction that lesion formation in normal versus scar tissue can be substantially different.2Specifically, ablation lesions in scar tissue were histologically quite heterogeneous, and connective tissue tended to be more resistant to thermal injury than normal myocardium.We have seen many cases where after identifying critical VT circuit components with activation and entrainment mapping, VT slowing and termination could only be achieved very late (4-5 minutes) into radiofrequency application, suggesting continued lesion expansion due to delayed effect of conductive heating in scar tissue can persist well beyond 3 minutes. Historical data from Nath, et al. have demonstrated that tissue temperature of >50°C must be reached in order to achieve nonreversible cellular damage.3 In the setting of dense scar, as in patients with healed myocardial infarction or dense basal septal scar in nonischemic cardiomyopathy, dynamics of tissue heating and lesion formation are likely quite different than in normal tissue. Especially in intramural substrates which are “protected” by dense subendocardial (or subepicardial if ablating from the epicardium) scar, ablation with very long (>3 minute) lesions may have a more pronounced effect than in normal tissue. While in our experience, steam pops seem to occur less frequently when ablating in dense scar- even with long, high power lesions, close monitoring of ablation parameters including catheter tip temperature and impedance remain necessary during ablation to assure continued safety to avoid char formation and steam pops.We enthusiastically applaud the authors for their valuable contribution to the literature. While chronic cardiomyopathy models are technically difficult to create and costly to maintain, additional studies examining lesion formation in dense scar would be extremely helpful to delineate optimal ablation strategies in patient with cardiomyopathy and difficult VT substrates. Our clinical experience with late VT termination and prevention of inducibility after 4-5 minute radiofrequency ablation lesions in areas of marked fibrosis would support such additional study.References:1. Rogers AJ, Borne RT, Ho G, Sauer WH, Wang PJ, Narayan SM, Zheng L, Nguyen DT. Continuous Ablation Improves Lesion Maturation Compared with Intermittent Ablation Strategies. J Cardiovasc Electrophysiol 2020.2. Barkagan M, Leshem E, Shapira-Daniels A, Sroubek J, Buxton AE, Saffitz JE, Anter E. Histopathological Characterization of Radiofrequency Ablation in Ventricular Scar Tissue. JACC Clin Electrophysiol 2019;5:920-931.3. Nath S, DiMarco JP, Gallop RG, McRury ID, Haines DE. Effects of dispersive electrode position and surface area on electrical parameters and temperature during radiofrequency catheter ablation. Am J Cardiol 1996;77:765-767.

Multipolar mapping has primarily been studied in complex arrhythmia substrates or re-entrant circuits. Chieng et al. use a Case-Control design to compare multipolar mapping and point-by-point mapping with an ablation catheter for focal atrial and ventricular tachycardias, showing reduced procedure times and earlier electrograms in the multipolar mapping group but no difference in clinical outcomes. It is plausible that faster mapping and better delineation of earliest signals may translate to improved clinical outcomes if studied in a randomized trial in a larger population. Future multipolar mapping systems will guide the operator toward the focus in real-time and may even triangulate the source in three dimensions, giving an estimate of depth within the myocardium or likely focus in the opposite chamber.

The field of electrophysiology continues to move further towards low fluoroscopy procedures. The deleterious effects of radiation exposure and of the radiation protection clothing themselves are the primary drivers of this approach. Radiation exposure is known to increase the risk of cancer and cataracts for all operators, and namely those who are subjected to accumulating doses of radiation over time. (1). Proper radiation protective clothing can significantly decrease these risks however this strategy has serious weaknesses. For instance, the protective clothing does not cover the whole body, leaving the face and the skull exposed. Roguin et al (2) showed that the risk of radiation exposure to the unprotected areas of the body is real and has serious consequences. In a cohort of 31 interventional cardiologists who developed brain cancer, the investigators showed that 22 (85%) of them had left sided tumors, and 17 (55%) of them had glioblastoma multiforme. This remarkable finding suggests that the dose left side of the brain, the side that gets more radiation exposure, is much more likely to develop a cancer that carries a poor prognosis and a median expected survival of 12 months. Furthermore, the radiation protective clothing itself can cause orthopedics injuries common among interventional cardiologists such those of the spine and the knees. Given the deleterious effects of radiation, low fluoroscopy approaches are welcomed by the electrophysiology community if they can show a safety profile similar to that with the use of fluoroscopy.The transseptal puncture (TSP) is arguably the most critical step during which fluoroscopy is used. In this study Singh et al describe an approach for TSP under electoanatomic guidance. The authors then retrospectively compare the total procedure duration, fluoroscopy time, radiation exposures, and complications related to the TSP using this method with those of conventional fluoroscopy. This was a single center study that included 145 consecutive patients, with no previous history of cardiac surgery, who underwent de novo and redo AF ablations between June 2018 and April 2019. These patients were then compared to cases performed by the same operators before June 2018. The procedure was done under conscious sedation. A dense electroanatomic map of the right atrium was acquired using CARTO 3 Fast Anatomical Mapping and Confidence Software, with emphasis on the atrial septum, His Bundle, coronary sinus ostium, and superior vena cava. The authors observed that the fossa ovalis was an area of low voltage potential (0.37±0.19 mV vs 1.73±0.74 mV) and low impedance (125±11 Ω vs 138±15 Ω), and electrically distinct from the rest of the atrial septum. The authors were able to localize the fossa ovalis using a combination of anatomical landmarks and the use of a voltage threshold of 0.75mV. The transseptal needle was then advanced through this desired location. The authors reported no significant complications related to the TSP.The authors argue that the safety profile is like the TSP under fluoroscopy, however this is a single center study. In fact the most senior operator performed three- quarters of all the procedures. Given the high risk of such an approach, the main question for the wide adoption of such a technique will again be safety in the hands of less experienced operators. A major factor that can increase the safety profile as well as the preciseness of the TSP is the routine use of ICE. ICE can confirm the precise positioning of the needle even in cases with unusual atrial septal anatomies (floppy, bulging, hypertrophic septum or in the presence of devices such as CardioSEAL or other atrial septal defect occlusion devices). Furthermore, ICE can confirm the location of the needle in the LA with microbubble injections after the TSP; it can confirm the location of the wire thus making it safer to advance the sheath knowing that it will not end up in the LAA or causing a perforation. As such ICE is arguably more important in the low fluoroscopy approach than in a one with fluoroscopy.Low fluoroscopy approach to TSP is a welcomed change in the field of electrophysiology given the significant adverse outcomes of radiation and radiation protective clothing to providers. The main concern in such a change is the safety and precise localization of the TSP. New technologies are allowing the development of new approaches such as the one described by Troisi et al to achieve the goal of safe low fluoroscopy procedures.References:Klein LW, Miller DL, Balter S, et al. Occupational health hazards in the interventional laboratory: time for a safer environment. Radiology 2009; 250:538-544.Roguin A, Goldstein J, Bar O, Goldstein JA. Brain and neck tumors among physicians performing interventional procedures. Am J Cardiol 2013;111(9):1368-72.

Impact of Pre-ablation Weight Loss on the Success of Catheter Ablation for Atrial FibrillationAbdul Hafiz Al Tannir BS, Marwan M. Refaat MDDepartment of Internal Medicine, Division of Cardiology, American University of Beirut Medical Center, Beirut, LebanonRunning Title: Pre-ablation Weight Loss and Success of AF AblationDisclosures: NoneFunding: NoneKeywords: Cardiac Arrhythmias, Cardiovascular Diseases, Heart Diseases, Weight Loss, Catheter Ablation, Atrial FibrillationWords: 621 (excluding references)Correspondence:Marwan M. Refaat, MD, FACC, FAHA, FHRS, FASE, FESC, FACP, FRCPAssociate Professor of MedicineDirector, Cardiovascular Fellowship ProgramDepartment of Internal Medicine, Cardiovascular Medicine/Cardiac ElectrophysiologyDepartment of Biochemistry and Molecular GeneticsAmerican University of Beirut Faculty of Medicine and Medical CenterPO Box 11-0236, Riad El-Solh 1107 2020- Beirut, LebanonFax: +961-1-370814Clinic: +961-1-759616 or +961-1-355500 or +961-1-350000/+961-1-374374 Extension 5800Office: +961-1-350000/+961-1-374374 Extension 5353 or Extension 5366 (Direct)Email: mr48@aub.edu.lbIn the United States, the prevalence of obese individuals has risen 3-fold since 1960, with 1 in every 3 persons being obese. The effect of weight changes on the progression on atrial fibrillation is well-established but the effect of pre-ablation weight loss on the recurrence of atrial fibrillation is not well-studied. Atrial fibrillation is the most frequently encountered cardiac arrhythmia [1]; it currently affects around 2.7 million people in the United States of America and is estimated that 6-12 million people will suffer from this condition by 2050 [2, 3]. Pulmonary vein isolation is the primary target for cardiac ablation; it can be achieved either by radiofrequency (RF) or cryoballoon ablation (CBA) [4, 5]. The FIRE and ICE trial conducted by Kuck et al showed that CBA therapy was associated with significantly fewer recurrence, rehospitalization, and cardioversion rates [6]. Several studies suggest the preferred use of CBA in treating atrial fibrillation in obese patients due to the increased surface area for ablation [4].Obesity has adverse effects on the structure and hemodynamics of the heart and it is a well-established risk factor for the development of atrial fibrillation [3]. A prospective cohort study performed by Pathak et al showed that progressive weight loss in obese and overweight patients resulted in dose-dependent effects on freedom from atrial fibrillation (FFAF) [7]. Similarly, Middeldrop et al, concluded that obesity is associated with the progression of the disease while weight loss is associated with reversal of the progression [8]. Limited data is available regarding the effect of weight loss on the recurrence of atrial fibrillation post-ablation. Current guidelines recommend lifestyle modifications, including a healthy diet and exercise, for overweight and obese patients before ablation [8, 9].The study of Peigh et al. is a retrospective cohort study from 2012-2017; 607 patients met the inclusion criteria. The aim of the study is to assess the impact of patient-directed weight loss 1 year before CBA on FFAP 15 months after ablation. The authors addressed an important topic that is poorly understood. Obese patients have a significantly lower FFAF rate 40-50% than the overall population 60-80%. The study selectively included patients undergoing CBA therapy. The follow-up time was 1-year post-ablation. The study concluded that, with the exception of non-obese patients with persistent atrial fibrillation, weight loss is associated with a significantly increased FFAF while weight gain led to a decrease in FFAF. A similar study assessed the impacted of physician-mediated risk control in patients undergoing RF ablation for atrial fibrillation [10]. A total of 149 patients were included in the prospective cohort study. The study showed a positive association between physician-directed weight loss (≥ 10%) and FFAF in symptomatic obese patients. The study performed by Peigh et al, included though a larger subject group (607) than LEGACY (141); however, the LEGACY is a prospective cohort study that is more suitable to monitor the fluctuation in patients’ variables before ablation.This study was well conducted but has the limitations of retrospective studies; a prospective cohort study would better monitor the variations in patients’ variables pre-ablation. In addition, as the authors stated, asymptomatic atrial fibrillation episodes may go unnoticed.Patients with atrial fibrillation, particularly those who are obese, should be advised to lose weight prior to catheter ablation. Lifestyle modifications should not be limited to patients undergoing ablation; the effect of weight loss on disease progression is well-established. Due to the overgrowing prevalence of atrial fibrillation and obesity worldwide, more studies are encouraged to better understand the ideal lifestyle management in patients. Larger prospective cohort studies should be conducted in order to validate the results. There is also an ongoing randomized clinical trial BAROS (Bariatric Atrial Return of Sinus Trial) [NCT 04050969] which will provide more data on this topic.

Pulmonary Vein Isolation-induced Vagal Nerve Injury and Gastric Motility DisordersBachir Lakkiss, MD; Marwan M. Refaat, MDDivision of Cardiology, Department of Internal Medicine, American University of Beirut Medical Center, Beirut, LebanonRunning Title: PVI-induced vagal nerve injury and gastric motility disordersWords: 665 (excluding the title page and references)Keywords: Heart Diseases, Cardiovascular Diseases, Cardiac Arrhythmias, Atrial Fibrillation, Catheter Ablation, Pulmonary Vein IsolationFunding: NoneDisclosures: NoneCorresponding Author:Marwan M. Refaat, MD, FACC, FAHA, FHRS, FRCPTenured Professor of MedicineTenured Professor of Biochemistry and Molecular GeneticsVan Dyck Medical Educator and Director of the Cardiovascular Fellowship ProgramDepartment of Internal Medicine, Cardiovascular Medicine/Cardiac ElectrophysiologyAmerican University of Beirut Faculty of Medicine and Medical CenterPO Box 11-0236, Riad El-Solh 1107 2020- Beirut, LebanonUS Address: 3 Dag Hammarskjold Plaza, 8th Floor, New York, NY 10017, USAOffice: +961-1-350000/+961-1-374374 Extension 5353 or Extension 5366 (Direct)Email: mr48@aub.edu.lbAtrial fibrillation (AF) is the most prevalent heart rhythm abnormality worldwide. An estimated three to six million people in the United States have AF. It is expected that this number is likely to double by 2050, making AF a significant public health burden. (1) AF is a leading cause of stroke and thromboembolism and is associated with a reduced quality of life. (2) Furthermore, it is linked to an increased mortality in both men and women, with an OR for death of 1.5 in men and 1.9 in women. (3) Medical expenditures for AF are significant, ranging from an annual cost of $1,632 to $21,099, with acute care accounting for the largest cost component in addition to anticoagulation therapy, which accounted for almost one-third of these costs. (4) The four pillars of AF management include rhythm control, rate control, stroke prevention and risk factor management. (5, 6) While antiarrhythmic drugs are used in some patients for AF rhythm control, AF ablation using pulmonary vein isolation (PVI) is regarded as the major modality for rhythm control. (6)The vagal nerve provides most of the parasympathetic innervation to the abdominal organs, including the stomach, esophagus, and a significant portion of the intestines. It serves a major role in the regulation of gastric and esophageal motility, in addition to maintaining lower esophageal sphincter tone. (7-9) Due to the relatively close vicinity of the vagal nerve plexus located on the anterior surface of the esophagus and the left atrial posterior wall, the thermal energy utilized during ablation can result in uncommon but potentially fatal complications such as esophageal perforation and atrial-esophageal fistula formation. (10-12) In addition, radiofrequency ablation for AF is associated with non-fatal complications such as an increased risk of gastric motility disorders and acid reflux. (13, 14)In the current issue of the Journal of Cardiovascular Electrophysiology, Meininghaus et al. recruited 85 patients to assess the incidence of ablation-induced vagal nerve injury (VNI) using both cryoballoon and radiofrequency ablation. Although many cases of VNI induced by PVI have been documented previously, this is one of the first studies to utilize electrophysiologic measurements of gastric motility (EGG) using cutaneous electrodes to record the electrical activity of the stomach two days prior to and two days after the procedure. (15-17) Moreover, the authors have used endoscopy to detect lesions such as erosions, ulcers, and perforations in the esophagus one week prior to and within two days of the procedure.The findings from this study add to our understanding of one of the complications of PVI in patients with AF (13, 14). One of the key outcomes the researchers observed was the perceived direct link between VNI and preexisting esophageal vulnerability. The authors have found that patients who had preexisting esophagitis had an elevated risk of developing VNI. In addition, the authors identified that in patients in whom EGG showed VNI, the elevated risk of ablation-induced endoscopic pathology was present in the post-procedure endoscopy. Furthermore, another significant finding was the detection of VNI on EGG in approximately one-third of PVI patients, irrespective of energy source, whether high power short duration, or moderate power moderate duration. These findings did not corroborate other studies, which showed that titration of the duration of the ablation energy could prevent VNI in patients undergoing AF ablation. (18)Overall, the authors should be commended for their tremendous efforts in attempting to understand the intricate pathophysiology and the association of esophageal lesions, atrial-esophageal fistula formation, and vagal nerve injury following PVI using EGG. Certainly, the results of this study have tremendous clinical implications. EGG could have a very important role in the prevention of atrial-esophageal fistula formation in the future. The article had a few limitations, mainly that the results were from a single-center study. Further studies incorporating additional patients from different medical centers should be conducted to better understand the complex pathophysiology of vagal nerve injury and gastric motility disorders following PVI. Advances in esophageal protection technologies will help in decreasing esophageal lesions during PVI. (19-20)References1. Miyasaka Y, Barnes ME, Gersh BJ, Cha SS, Bailey KR, Abhayaratna WP, et al. Secular Trends in Incidence of Atrial Fibrillation in Olmsted County, Minnesota, 1980 to 2000, and Implications on the Projections for Future Prevalence. Circulation. 2006;114(2):119-25. doi: doi:10.1161/CIRCULATIONAHA.105.595140.2. Jalloul Y, Refaat MM. IL-6 Rapidly Induces Reversible Atrial Electrical Remodeling by Downregulation of Cardiac Connexins. J Am Heart Assoc. 2019;8(16):e013638. Epub 2019/08/20. doi: 10.1161/jaha.119.013638. PubMed PMID: 31423871; PubMed Central PMCID: PMCPMC6759896.3. Benjamin EJ, Wolf PA, D’Agostino RB, Silbershatz H, Kannel WB, Levy D. Impact of atrial fibrillation on the risk of death: the Framingham Heart Study. Circulation. 1998;98(10):946-52. Epub 1998/09/16. doi: 10.1161/01.cir.98.10.946. PubMed PMID: 9737513.4. Wodchis WP, Bhatia RS, Leblanc K, Meshkat N, Morra D. A review of the cost of atrial fibrillation. Value Health. 2012;15(2):240-8. Epub 2012/03/22. doi: 10.1016/j.jval.2011.09.009. PubMed PMID: 22433754.5. Lakkis B, Refaat MM. Is esophageal temperature management needed during cryoballoon ablation for atrial fibrillation? Journal of Cardiovascular Electrophysiology. 2022;33(12):2567-8. doi: https://doi.org/10.1111/jce.15725.6. Chung MK, Refaat M, Shen W-K, Kutyifa V, Cha Y-M, Di Biase L, et al. Atrial Fibrillation: JACC Council Perspectives. Journal of the American College of Cardiology. 2020;75(14):1689-713. doi: https://doi.org/10.1016/j.jacc.2020.02.025.7. Richards WG, Sugarbaker DJ. Neuronal control of esophageal function. Chest Surg Clin N Am. 1995;5(1):157-71. Epub 1995/02/01. PubMed PMID: 7743145.8. Hsu M, Safadi AO, Lui F. Physiology, Stomach. StatPearls. Treasure Island (FL): StatPearls PublishingCopyright © 2022, StatPearls Publishing LLC.; 2022.9. Goyal RK, Chaudhury A. Physiology of normal esophageal motility. J Clin Gastroenterol. 2008;42(5):610-9. Epub 2008/03/28. doi: 10.1097/MCG.0b013e31816b444d. PubMed PMID: 18364578; PubMed Central PMCID: PMCPMC2728598.10. Kapur S, Barbhaiya C, Deneke T, Michaud GF. Esophageal Injury and Atrioesophageal Fistula Caused by Ablation for Atrial Fibrillation. Circulation. 2017;136(13):1247-55. doi: doi:10.1161/CIRCULATIONAHA.117.025827.11. D’Avila A, Ptaszek LM, Yu PB, Walker JD, Wright C, Noseworthy PA, et al. Images in cardiovascular medicine. Left atrial-esophageal fistula after pulmonary vein isolation: a cautionary tale. Circulation. 2007;115(17):e432-3. Epub 2007/05/02. doi: 10.1161/circulationaha.106.680181. PubMed PMID: 17470703.12. Sánchez-Quintana D, Cabrera JA, Climent V, Farré J, Mendonça MCd, Ho SY. Anatomic Relations Between the Esophagus and Left Atrium and Relevance for Ablation of Atrial Fibrillation. Circulation. 2005;112(10):1400-5. doi: doi:10.1161/CIRCULATIONAHA.105.551291.13. Shah D, Dumonceau J-M, Burri H, Sunthorn H, Schroft A, Gentil-Baron P, et al. Acute Pyloric Spasm and Gastric Hypomotility: An Extracardiac Adverse Effect of Percutaneous Radiofrequency Ablation for Atrial Fibrillation. Journal of the American College of Cardiology. 2005;46(2):327-30. doi: https://doi.org/10.1016/j.jacc.2005.04.030.14. Park S-Y, Camilleri M, Packer D, Monahan K. Upper gastrointestinal complications following ablation therapy for atrial fibrillation. Neurogastroenterology & Motility. 2017;29(11):e13109. doi: https://doi.org/10.1111/nmo.13109.15. Choi SW, Kang SH, Kwon OS, Park HW, Lee S, Koo BS, et al. A case of severe gastroparesis: indigestion and weight loss after catheter ablation of atrial fibrillation. Pacing Clin Electrophysiol. 2012;35(3):e59-61. Epub 2010/10/05. doi: 10.1111/j.1540-8159.2010.02912.x. PubMed PMID: 20883511.16. Lakkireddy D, Reddy YM, Atkins D, Rajasingh J, Kanmanthareddy A, Olyaee M, et al. Effect of atrial fibrillation ablation on gastric motility: the atrial fibrillation gut study. Circ Arrhythm Electrophysiol. 2015;8(3):531-6. Epub 2015/03/17. doi: 10.1161/circep.114.002508. PubMed PMID: 25772541.17. Kuwahara T, Takahashi A, Takahashi Y, Kobori A, Miyazaki S, Takei A, et al. Clinical characteristics and management of periesophageal vagal nerve injury complicating left atrial ablation of atrial fibrillation: lessons from eleven cases. J Cardiovasc Electrophysiol. 2013;24(8):847-51. Epub 2013/04/05. doi: 10.1111/jce.12130. PubMed PMID: 23551640.18. KUWAHARA T, TAKAHASHI A, KOBORI A, MIYAZAKI S, TAKAHASHI Y, TAKEI A, et al. Safe and Effective Ablation of Atrial Fibrillation: Importance of Esophageal Temperature Monitoring to Avoid Periesophageal Nerve Injury as a Complication of Pulmonary Vein Isolation. Journal of Cardiovascular Electrophysiology. 2009;20(1):1-6. doi: https://doi.org/10.1111/j.1540-8167.2008.01280.x.19. D’Avila A, Ptaszek LM, Yu PB, Walker JD, Wright C, Noseworthy PA, Myers A, Refaat M, Ruskin JN: Left Atrial-Esophageal Fistula After Pulmonary Vein Isolation. Circulation May 2007; 115(17): e432-3.20. El Moheb MN, Refaat MM. Protecting the Esophagus During Catheter Ablation: Evaluation of a Novel Vacuum Suction-Based Retractor. J Cardiovasc Electrophysiol Jul 2020; 31 (7): 1670-1671.