Optimizing radiofrequency ablation of paroxysmal and persistent atrial fibrillation by direct catheter force measurement-a case-matched comparison in 198 patients.

BACKGROUND: Sufficient electrode-tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA). OBJECTIVE: We assessed the impact of direct catheter force measurement on acute procedural parameters and outcome of RFCA for paroxysmal and persistent atrial fibrillation (AF). METHODS: Ninety-nine consecutive patients (70% men) with paroxysmal (63.6%) or persistent AF underwent left atrial RFCA using a 3.5-mm open-irrigated-tip (OIT) catheter with contact force measurement capabilities (group 1). For comparison a case-matched cohort with standard OIT catheters was used (99 patients; group 2). Case matching included gender, type of AF, number or RFCA procedures, and type of procedure. RESULTS: Procedural data showed a significant decline in radiofrequency ablation time from 52 ± 20 to 44 ± 16 minutes (P = 0.003) with a remarkable mean reduction in overall procedure time of 34 minutes (P = 0.0001; 225.8 ± 53.1 vs 191.9 ± 53.3 minutes). In parallel, the total fluoroscopy time could be significantly reduced from 28.5 ± 11.0 to 19.9 ± 9.3 minutes (P = 0.0001) as well as fluoroscopy dose from 74.1 ± 58.0 to 56.7 ± 38.9 Gy/cm(2) (P = 0.016). Periprocedural complications were similar in both groups. CONCLUSIONS: The use of contact force sensing technology is able to significantly reduce ablation, procedure, and fluoroscopy times as well as dose in RFCA of AF in a mixed case-matched group of paroxysmal and persistent AF. Energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact. Additionally 12-month outcome data showed increased efficacy. Such time saving and equally safe technology may have a relevant impact on laboratory management and increased cost effectiveness.

Asymptomatic cerebral lesions during pulmonary vein isolation under uninterrupted oral anticoagulation.

AIMS: Left atrial radiofrequency ablation has been shown to carry a risk of asymptomatic cerebral lesions. No data exist in patients under continued oral anticoagulation during the ablation procedure. The aim of this study was to quantify the amount of silent cerebral lesions assessed by pre-procedural and post-procedural magnetic resonance imaging (MRI) in patients under therapeutic international normalized ratio (INR) and to identify clinical or procedural parameters that correlate with cerebral embolism. METHODS AND RESULTS: A total of 131 consecutive patients undergoing catheter ablation for paroxysmal (n = 80, 61.1%) or persistent (n = 51, 38.9%) atrial fibrillation were included in the study. Pulmonary vein antrum isolation (PVI), roofline, mitral isthmus line, and complex fractionated atrial electrogram (CFAE) ablation using 3.5 mm open-irrigated tip catheters were performed, as needed. All patients underwent pre-procedural and post-procedural cerebral MRI. Post-procedural MRI revealed new embolic lesions in 16 patients (12.2%), all of them asymptomatic. Clinical parameters showing a significant correlation with cerebral embolism in univariate analysis were age (P = 0.027), persistent atrial fibrillation (vs. paroxysmal; P = 0.039), and spontaneous echo contrast in transesophageal echocardiography (P = 0.029). Significant procedural parameters were electric cardioversion (P = 0.041), PVI only (P = 0.008), and ablation of complex atrial electrograms (P = 0.005). Independent risk factors in multivariate analysis were age (P = 0.009), spontaneous echo contrast (P = 0.029) and CFAE ablation (P = 0.006). CONCLUSION: Radiofrequency ablation in patients under continued oral therapeutic anticoagulation is associated with a substantial risk of silent embolism detected by cerebral MRI. Therefore, continuation of oral anticoagulation is not able to prevent cerebral embolism. A variety of different clinical and procedural factors seem to contribute to the risk of cerebral lesions.

Clinical impact of an open-irrigated radiofrequency catheter with direct force measurement on atrial fibrillation ablation.

BACKGROUND: Electrode-tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA). OBJECTIVE: We assessed the impact of direct catheter force measurement on acute procedural parameters during RFCA of atrial fibrillation (AF). METHODS: Fifty consecutive patients (28 male) with paroxysmal AF who underwent their first procedure of circumferential pulmonary vein (PV) isolation (PVI) were assigned to either RFCA using (1) a standard 3.5-mm open-irrigated-tip catheter or (2) a catheter with contact force measurement capabilities. Using the endpoint of PVI with entry and exit block, acute procedural parameters were assessed. RESULTS: Procedural data showed a remarkable decline in ablation time (radiofrequency time needed for PVI) from 50.5 ± 15.9 to 39.0 ± 11.0 minutes (P = 0.007) with a reduction in overall procedure duration from 185 ± 46 to 154 ± 39 minutes (P = 0.022). In parallel, the total energy delivered could be significantly reduced from 70,926 ± 19,470 to 58,511 ± 14,655 Ws (P = 0.019). The number of acute PV reconnections declined from 36% to 12% (P = 0.095). CONCLUSIONS: The use of contact force sensing technology is able to significantly reduce ablation and procedure times in PVI. In addition, energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact. Procedural efficacy and safety of this new feature have to be evaluated in larger cohorts.

Cerebral thromboembolic risk in atrial fibrillation ablation: a direct comparison of vitamin K antagonists versus non-vitamin K-dependent oral anticoagulants.

PURPOSE: Cerebral thromboembolic events are well-known complications of pulmonary vein isolation (PVI) and can manifest as stroke or silent cerebral embolic lesions. The aim of this study was to compare the incidence of cerebral embolic lesions (including silent cerebral embolism and stroke) after AF ablation in patients on vitamin K antagonists versus patients on non-vitamin K-dependent oral anticoagulants, and to identify corresponding clinical and procedural risk factors. METHODS: A total of 421 patients undergoing PVI were prospectively included into the study. Of these, 43.7% were on VKA and 56.3% on NOAC treatment (dabigatran, rivaroxaban, apixaban, and edoxaban). In the NOAC group, 38% of patients had an interruption of anticoagulation for 24-36 h. All patients underwent pre- and postprocedural cerebral magnetic resonance imaging. RESULTS: Periprocedural cerebral lesions occurred in 13.1% overall. Of these, three (0.7%) resulted in symptomatic cerebrovascular accidents and 52 (12.4%) in silent cerebral embolic lesions. Incidence of cerebral lesions was significantly higher in patients on NOAC compared with VKA (16% vs. 9.2%, respectively, p = 0.04), and in patients who had intraprocedural cardioversions compared with no cardivoersions (19.5% vs. 10.4%, respectively, p = 0.03). In multivariate analysis, both parameters were found to be independent risk factors for cerebral embolism. No significant difference between interrupted and uninterrupted NOAC administration could be detected. CONCLUSIONS: In patients undergoing AF ablation, we identified the use of NOAC and intraprocedural cardioversion as independent risk factors for the occurrence of periprocedural cerebral embolic lesions.

[Endo- and epicardial catheter ablation preventing ventricular tachycardia: impact of substrate modification]. / Endo- und epikardiale katheterablation in der behandlung ventrikulärer tachykardien: bedeutung der substratmodifikation.

Challenges encountered during catheter ablation of ventricular tachycardia (VT) include hemodynamic instability and lack of inducibility. Recent approaches guided by electroanatomic mapping demonstrated the feasibility of VT ablation during sinus rhythm. We analyzed the data from 40 consecutive patients who were referred to the Elisabethinen Hospital Linz for VT ablation. Ablation target sites were identified by using pace-, electroanatomic, and specific VT-related potential mapping. All clinical VTs were eliminated by catheter ablation in 38 of 40 patients within 43 procedures. Epicardial mapping and ablation via a subxiphoid percutaneous access was necessary in 3 patients. In total, 4 out of 14 patients with a history of frequent ICD shocks received additional ICD discharges during follow-up (n = 2:ICD-shock; n = 2:antitachycardia-pacing). Combining pace-, activation-, entrainment-, and substrate-mapping is useful for VT prevention by catheter ablation. A subxiphoid percutaneous approach is useful in some patients for extensive mapping and ablation at the epicardial surface of the heart.

Long-term experience with implantable infusion pumps for intravenous treprostinil in pulmonary arterial hypertension-procedural safety and system-related complications.

Implantable pumps for intravenous treprostinil provide a promising option to overcome drawbacks of parenteral prostanoid administration with external pumps in pulmonary hypertension. We retrospectively analyzed 85 patients undergoing implantation in a single center since 2010. In our cohort, serious complications were rare, and flow rate increase over time warrants careful monitoring.

Indications and Outcome in Patients Undergoing Left Atrial Appendage Closure-The Austrian LAAC Registry.

BACKGROUND: Complete real-world data on the indications and outcomes of left atrial appendage closure (LAAC) outside of clinical trials are rare. In this study, we stratified patients undergoing LAAC by indication groups. METHODS: This analysis of the national multicentre Austrian LAAC Registry comprised all patients that underwent LAAC up until 2018 at the currently active centres in Austria. The baseline characteristics, procedural details and outcomes between the following indication groups were compared: bleeding as an indication for LAAC ("bleeding" group) vs. thromboembolism despite oral anticoagulation (OAC; "thromboembolism" group) vs. an intolerance to OAC for reasons other than the above ("other" group). RESULTS: The analysis included 186 patients, with 59.7% in the "bleeding" group, 8.1% in the "thromboembolism" group and 32.2% in the "other" group. The CHADS2 score was the highest in the "thromboembolism" group and the HAS-BLED score was the highest in the "bleeding" group. The procedural outcomes were similar between groups (implantation success, 97.3%), with major complications occurring in 7.0% of patients. One-year survival free from stroke, bleeding or LAAC-associated hospitalisation was 83.9%, 90.0% and 81.4% in the "bleeding", "thromboembolism" and "other" groups, respectively (p = 0.891). CONCLUSIONS: In routine clinical practice, LAAC was used in a heterogeneous patient population with atrial fibrillation (AF) and contraindication, inefficacy or intolerance to OAC. The long-term outcome was favourable in all groups.

Acute effects of complex fractionated atrial electrogram ablation on dominant frequency and regulatory index for the fibrillatory process.

AIMS: The purpose of our study was to determine the acute effects of complex fractionated electrograms (CFAE) ablation guided by automated detection on dominant frequency (DF) and regulatory index (RI) for the fibrillatory process. METHODS AND RESULTS: The study included 41 patients (21 paroxysmal and 20 persistent) referred for catheter ablation of atrial fibrillation (AF). Our ablation strategy included pulmonary vein isolation (PVI) as first step, CFAE ablation as second step, roof line ablation as next, and mitral isthmus ablation as last step. On the CFAE map, we were targeting only points outside the previous PVI lines. Simultaneously, we evaluated DF and RI changes in the coronary sinus after each step of ablation. The termination rate by CFAE ablation was low (12.5% in paroxysmal and 10% in persistent AF). Changes in DF and RI after CFAE ablation were not significant (<0.25 Hz and max. 0.02 increase for RI) compared with other ablation steps. Pulmonary vein isolation, roof line, and mitral isthmus ablation resulted in significant changes in DF and RI. CONCLUSION: On the basis of our results, CFAE ablation guided by a dedicated software algorithm and performed after standard PVI without CFAE remapping does not influence the fibrillatory process significantly. Application of a modified algorithm with different settings warrants further investigations.

Ranolazine: impact on quality of life in patients with stable angina pectoris, results from an observational study in Austria - the ARETHA AT study.

OBJECTIVE: Assessment of treatment routine and outcome for ranolazine in clinical practice as second-line treatment for stable angina pectoris (AP). DESIGN AND SETTING: Multicenter, prospective, uncontrolled, non-interventional study at 88 sites including internal specialists, cardiologists, pneumologists, angiologists and primary care practices in Austria. PARTICIPANTS: In this study 292 patients receiving ranolazine in the course of routine treatment on top of beta blockers or calcium channel blockers after failure of first-line therapy. MAIN OUTCOME MEASURES: Dosage and symptoms were recorded at two visits (at intervals of 12 weeks), complemented by treatment rationale and disease characteristics at baseline. Disease intensity was quantified by angina symptoms, nitrate use and by Canadian Cardiovascular Society (CCS) grading. Quality of life (QoL) was assessed through a 10-grade scale. Data were analyzed by descriptive statistics. RESULTS: Ranolazine was prescribed in order to improve exercise capacity (84.3%), reduce symptoms (83.2%) and reduce AP (77.1%). Of the patients 87.3% received the recommended starting dose of 375 mg and subsequent dose changes were reported for 39.8%. The number of AP attacks was reduced from 5.3 ± 4.5 to 0.8 ± 1.3 per week; nitrate use was reduced from 3.4 ± 4.1 to 0.4 ± 0.9 applications per week. Of the patients 94.0% reported improved exercise capacity and 93.7% reduced symptoms. For the majority of patients, the CCS improved from grade II to I and QoL improved accordingly. Of the patients 3 experienced adverse drug reactions and 95.5% continued ranolazine. CONCLUSION: In this real-world study, ranolazine was shown to be effective, safe and well tolerable. Symptoms of AP were improved, as illustrated by the reduced number of angina attacks, reduced rate of nitrate use, reduced CCS scores and improved QoL.

Functional status and life satisfaction of patients with stable angina pectoris in Austria.

OBJECTIVES: Although substantial progress in the treatment of stable angina pectoris (sAP) has been made, little is known about the functional status and quality of life (QoL) of patients in different healthcare systems. DESIGN AND METHODS: We undertook a survey using the Seattle Angina Questionnaire (SAQ) (five domains scored form 0-worst assessment to 100-best assessment) to assess symptoms, QoL (including limitation of activities), demographics, geographic distribution and individual disease data in patients with stable coronary artery disease in Austrian cardiology practices. RESULTS: A total of 660 patients with sAP with a mean age of 69.2 years were included. SAQ scores were 67.5±24.4 for physical limitation, 65.5±26.6 for angina stability, 79.3±23.2 for angina frequency, 86.3±16.2 for treatment satisfaction and 63.7±24.2 for overall QoL. Multiple regression identified male gender, but also female gender, Eastern Austrian residence and high body mass index as predictive factors for SAQ scoring. A total of 35.6% of the patients reported at least one desirable activity that was limited through AP symptoms. CONCLUSIONS: Activity and QoL assessments are in accordance with published literature: The number and the diversity of desired activities indicate the need to focus on patient's individual activity level to improve symptom management.

New insights into long-term follow-up of atrial fibrillation ablation: full disclosure by an implantable pacemaker device.

INTRODUCTION: Long-term outcome of radiofrequency ablation (RFA) for atrial fibrillation (AF) is difficult to assess. This study sought to evaluate various aspects of very long-term follow-up (FU) by the properties of an implantable device. METHODS: Fourteen patients with an implanted pacemaker device (Medtronic AT500) were selected for RFA, due to drug-refractory and highly symptomatic AF despite antibradycardic pacing. RESULTS: With a mean FU of 41.4 +/- 15.1 months, we could achieve continuous monitoring for more than 400,000 hours after RFA. Based on symptomatic episodes, simulated 24-hour, 48-hour, or 7-day Holter, 57% to 71% of the patients were classified as RFA responders. With permanent FU provided by the implanted device, 43% of the patients exhibited a positive treatment effect and only 21% had no tachyarrhythmic episode at all in long-term FU. With a mean of 1.7 +/- 0.7 RFA per subject, atrial tachyarrhythmia burden (ATB) was significantly reduced from a median of 3.6 to 0.3 hours per day (P < 0.001). Two out of 14 patients developed AF recurrences after a tachyarrhythmia-free period of more than 12 months. CONCLUSION: Continuous monitoring provided by an implantable device is able to detect significantly more AF episodes than routine FU. ATB is decreased significantly by (repeated) RFA over a very long-term FU. AF may reoccur very late after long-lasting (>1 year) episode-free intervals. A subgroup of patients with drug-aggravated bradycardia in brady-tachy syndrome might be considered for PV isolation rather than pacemaker implantation.

Pacemaker-Mediated Programmable Hypertension Control Therapy.

BACKGROUND: Many patients requiring a pacemaker have persistent hypertension with systolic blood pressures above recommended levels. We evaluated a pacemaker-based Programmable Hypertension Control (PHC) therapy that uses a sequence of variably timed shorter and longer atrioventricular intervals. METHODS AND RESULTS: Patients indicated for dual-chamber pacing with office systolic blood pressure (oSBP) >150 mm Hg despite stable medical therapy were implanted with a Moderato™ pulse generator that delivers PHC therapy. Patients were followed for 1 month (Run-In period) with conventional pacing; those with persistent oSBP >140 mm Hg were included in the study and had PHC therapy activated. The co-primary efficacy end points were changes in 24-hour ambulatory systolic blood pressure and oSBP between baseline and 3 months. Safety was assessed by tracking adverse events. Thirty-five patients met the initial inclusion criteria and underwent Moderato implantation. At 1 month, oSBP was <140 mm Hg in 7 patients who were excluded. PHC was activated in the remaining 27 patients with baseline office blood pressure 166±11/80±10 mm Hg despite an average of 3.2 antihypertensive medications. During the Run-In period, oSBP and 24-hour ambulatory systolic blood pressure decreased by 8±13 and 5±12 mm Hg (P<0.002), respectively. Compared with pre-PHC activation measurements, oSBP decreased by another 16±15 mm Hg and 24-hour ambulatory systolic blood pressure decreased by an additional 10±13 mm Hg (both P<0.01) at 3 months. No device-related serious adverse effects were noted. CONCLUSIONS: In pacemaker patients with persistent hypertension despite medical therapy, oSBP and 24-hour ambulatory systolic blood pressure are decreased by PHC therapy. Initial indications are that this therapy is a safe and promising therapy for such patients. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02282033.

Accuracy of integration of multislice computed tomography imaging into three-dimensional electroanatomic mapping for real-time guided radiofrequency ablation of left atrial fibrillation-influence of heart rhythm and radiofrequency lesions.

Circumferential radiofrequency ablation around the orifices of the pulmonary veins is a curative catheter-based therapy of paroxysmal and persistent atrial fibrillation (AF). Three-dimensional cardiac image integration is a promising new technology to visualize the complex left atrial anatomy and neighbouring structures. This study aimed to validate the accuracy of integrating multislice computed tomography (MSCT) into three-dimensional electroanatomic mapping (EAM) to guide radiofrequency catheter ablation (CA) of AF. Forty consecutive patients (34 male, mean age 56 +/- 10 years) with multidrug-resistant AF underwent 16-slice MSCT 1 day before radiofrequency CA. MSCT data were processed and imported to the Cartotrade mark EAM system. Using the CartoMergetrade mark Image Integration Module, the generated EAM was aligned with the MSCT images. An integrated statistical algorithm provided information about the accuracy of the fusion process. In every single patient, MSCT images could be aligned with the EAM. Mean distance between the EAM points (n = 63 +/- 14) and the MSCT surface was 1.6 +/- 1.2 mm with no difference between sinus rhythm versus AF (p = 0.145) and no distinction between patients in paroxysmal versus persistent/permanent AF despite a significant difference in left atrial diameters. An average of 388 +/- 81 radiofrequency ablation points were taken within the procedures resulting in a mean distance of 2.3 +/- 1.8 mm between the EAM points and the MSCT image after the ablation procedure. There was a significant difference of alignment accuracy before and after radiofrequency CA (p < 0.001). MSCT images can be accurately integrated into three-dimensional EAM. Pre-interventional cardiac rhythm does not influence the precision of fusion. Accuracy of fusion deteriorates after radiofrequency CA.

Acute myocarditis with normal wall motion detected with 2D speckle tracking echocardiography.

UNLABELLED: SummaryWe present the case of a 26-year-old male with acute tonsillitis who was referred for coronary angiography because of chest pain, elevated cardiac biomarkers, and biphasic T waves. The patient had no cardiovascular risk factors. Echocardiography showed no wall motion abnormalities and no pericardial effusion. 2D speckle tracking revealed distinct decreased regional peak longitudinal systolic strain in the lateral and posterior walls. Ischemic disease was extremely unlikely in view of his young age, negative family history regarding coronary artery disease, and lack of regional wall motion abnormalities on the conventional 2D echocardiogram. Coronary angiography was deferred as myocarditis was suspected. To confirm the diagnosis, cardiac magnetic resonance tomography (MRT) was performed, showing subepicardial delayed hyperenhancement in the lateral and posterior walls correlating closely with the strain pattern obtained by 2D speckle tracking echocardiography. With a working diagnosis of acute myocarditis associated with acute tonsillitis, we prescribed antibiotics and nonsteroidal anti-inflammatory drugs. The patient's clinical signs resolved along with normalization of serum creatine kinase (CK) levels, and the patient was discharged on the third day after admission. LEARNING POINTS: Acute myocarditis can mimic acute coronary syndromes.Conventional 2D echocardiography lacks specific features for detection of subtle regional wall motion abnormalities.2D speckle tracking expands the scope of echocardiography in identifying myocardial dysfunction derived from edema in acute myocarditis.

Expert position paper on prolonged dual antiplatelet therapy in secondary prevention following myocardial infarction.

The protective effect of dual antiplatelet therapy (DAPT) following acute coronary syndrome is undisputed, but its duration is subject of debate. Several studies show that prolonged therapy provides a clinical benefit in patients following acute coronary syndrome. The aim of this position paper authored by Austrian experts is to outline the current evidence and provide an overview of recent studies. It is also intended to serve as a practical guide to identify those patients who may benefit from prolonged DAPT.

Quality of life restored to normal in patients with atrial fibrillation after pulmonary vein ostial isolation.

BACKGROUND: Pulmonary vein isolation (PVI) is effective in patients with paroxysmal atrial fibrillation. However, its impact on quality of life (QOL) is not completely understood. METHODS: Eighty-nine otherwise healthy patients (74 men; age, 53 +/- 11 years) were selected for PVI. The Medical Outcomes Short Form 36 (SF-36) and the Symptom Checklist (SCL) QOL questionnaires were obtained before PVI and for as long as 6 months after PVI. RESULTS: A total of 294 PVs (3.3 PVs/patient) were targeted in 125 procedures (1.4/patient). After a mean follow-up period of 191 +/- 109 days, scores for SCL frequency (19.09 +/- 8.07 vs 10.67 +/- 6.61), SCL severity (15.97 +/- 7.68 vs 9.72 +/- 5.98), SF-36 physical composite (45.43 +/- 9.70 vs 51.70 +/- 6.52), and SF-36 mental composite (44.50 +/- 11.33 vs 51.67 +/- 8.73) improved significantly (P <.0001 each). Seventy-five patients provided data at both the baseline and a late (3- or 6-month) follow-up. This cohort had significantly worse QOL scores in 7 of the 8 SF-36 subscales at baseline compared with age-matched healthy control subjects, but their QOL scores were similar to a comparison group of 152 previously reported patients with atrial fibrillation receiving drug treatment who had similar demographic and clinical variables. After PVI, patients improved significantly, resulting in equivalence with the healthy control population. Logistic regression analysis of demographic variables and baseline QOL scores revealed no significant predictors of PVI responders. CONCLUSIONS: QOL measures in patients with paroxysmal atrial fibrillation are severely depressed before PVI. Within a 6-month follow-up period after ablation, SF-36 subscale scores were restored to equivalence with an age-matched, healthy control population. Neither demographic or clinical variables nor baseline QOL scores were predictive of response to PVI.

Incidence, management, and outcome in significant pulmonary vein stenosis complicating ablation for atrial fibrillation.

This study summarizes our results in diagnosing and treating pulmonary vein stenosis complicating ablation for atrial fibrillation in 6 of 92 patients. Patients with significant pulmonary vein narrowing underwent either dilatation or dilatation plus stenting. Pulmonary vein intervention produced a favorable clinical course over the following 7 +/- 2 months despite significant restenosis in 2 patients.

Identification of a high-risk population for esophageal injury during radiofrequency catheter ablation of atrial fibrillation: procedural and anatomical considerations.

BACKGROUND: Atrioesophageal fistula is an uncommon but life-threatening complication of atrial fibrillation (AF) ablation. Esophageal ulcerations (ESUL) have been proposed to be potential precursor lesions. OBJECTIVE: The purpose of our study was to prospectively investigate the incidence of ESUL in a large patient population undergoing radiofrequency catheter ablation (RFA). Additionally, we aimed to link demographic data and lesion sets with anatomical information given by multislice computed tomography imaging and to correlate these data with the development of ESUL. METHODS: This study included 267 patients and consecutively screened all individuals for evidence of ESUL 24 h after RFA of AF by endoscopy of the esophagus. A standardized ablation approach using a 25-W energy maximum at the posterior left atrial (LA) wall without esophagus visualization, temperature monitoring, or intracardiac ultrasound was performed. RESULTS: In total, we found 2.2% of patients (6 of 267) presenting with ESUL. Parameters exposing a specific patient to risk of developing ESUL in univariate analysis were persistent AF (5 of 95, P = .023), additional lines performed (roofline: 6 of 114, P = .006; LA isthmus: 4 of 49, P = .011; coronary sinus: 5 of 66, P = .004), and LA enlargement (P = .001) leading to sandwiching of the esophagus between the LA and thoracic spine. Multivariate analysis revealed LA-to-esophagus distance as the only significant risk factor. CONCLUSION: This study is the first to link anatomical information and procedural considerations to the development of ESUL in radiofrequency ablation for AF. Furthermore, it reveals the correlation and individual impact of these factors. Not a single patient with pulmonary vein isolation alone developed ESUL.