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BACKGROUND Nonchicken wing left atrial appendage (LAA) morphology is associated with higher risk for stroke in patients with atrial fibrillation (AF) than chicken wing (CW) morphology. OBJECTIVE Assess whether LAA morphology predicts the formation of LAA thrombus independent of age, sex, presenting rhythm, left ventricular ejection fraction (LVEF), or anticoagulant use. METHODS A cross-sectional analysis was performed on patients prospectively enrolled in the Vanderbilt LAA Registry or presenting for transesophageal echocardiogram (TEE) between January 1, 2015, and November 1, 2017 (n = 306). Two physicians independently reviewed TEEs interpreted as having LAA thrombus. Determination of LAA morphology, ejection velocity, and presence of thrombus (n = 102) were based on 0°, 45°, 90°, and 135° TEE views. The control cohort (n = 204) included consecutive AF patients undergoing TEE without LAA thrombus. RESULTS LAA morphology in patients with LAA thrombus was: 35% windsock, 47% broccoli, and 12% CW. Windsock (odds ratio [OR], 4.0; 95% confidence interval [CI]: 1.7-9.3, p = .001) and broccoli (OR, 6.6; 95% CI: 2.6-16.6; p

BACKGROUND Left atrial appendage (LAA) closure with the Watchman device is increasingly used in patients with nonvalvular atrial fibrillation for stroke prevention. Though clinical trials have shown a similar combined risk of ischemic and hemorrhagic stroke, there is an increased risk of ischemic stroke in patients with a Watchman device compared with anticoagulation. Some ischemic strokes are related to a device-related thrombus (DRT), which may be attributable to delayed endothelialization of exposed fabric and metal. METHODS AND RESULTS Patients undergoing Watchman LAA occlusion between January 2016 and June 2018 were enrolled in a prospective registry. From this cohort, 46 patients who had both transesophageal echocardiogram (TEE) and computed tomography (CT) at 45 days follow-up were selected for this study. The degree of LAA occlusion and type of leak were assessed by CT and TEE. TEE identified no patients with a significant (>5 mm) peri-device leak, 27 (58.6%) with nonsignificant peri-device leak (

INTRODUCTION It is common to find residual stump after the amputation or clip exclusion of the left atrial appendage (LAA). We evaluated the arrhythmogenic and thrombogenic potential of LAA stumps in atrial fibrillation (AF) patients. METHODS Consecutive patients undergoing catheter ablation for AF recurrence with LAA stump detected at baseline transesophageal echocardiogram (TEE) were included in the analysis. Nonpulmonary vein (non-PV) triggers were ablated based on operator's discretion. RESULTS A total of 213 patients with LAA stump were included in the analysis. Firing from the LAA stump was detected in 186 cases, of which 145 received stump isolation (group I) and the stump was not targeted for isolation in 41 (group II) patients. In 27 patients with no firing from the stump (group III) only non-PV triggers from sites other than the LAA stump were targeted for ablation. At 16.7 ± 8.5 months of follow-up, 126 (86.9%) patients from group I, eight (19.5%) from group II, and eight (33.3%) from group III remained arrhythmia-free off antiarrhythmic drugs (AAD) (P

Introduction Left atrial appendage (LAA) closure with the WATCHMAN device, according to FDA labelling, is recommended in patients with a maximal LAA ostial width between 17–31 mm. The safety and efficacy of LAA closure in patients with a maximal LAA ostial width 5 mm and no device related thrombi. Warfarin was discontinued in all 31 patients 45 days after LAA closure. Conclusions LAA closure with the WATCHMAN device can be successfully and safely achieved in patients with a maximal LAA ostial width

Introduction Electrical isolation of the left atrial appendage (LAA) is an important adjunctive ablation strategy in patients with nonparoxysmal atrial fibrillation (AF). Patients who have impaired LAA contractility following isolation may require long-term oral anticoagulant (OAC) therapy irrespective of their CHADS2 -VASc score. Percutaneous LAA occlusion (LAAO) is a potential alternative to life-long OAC therapy. We aimed to assess the rate of OAC discontinuation and thromboembolic (TE) events following percutaneous LAAO in patients who underwent LAA electrical isolation (LAAI). Methods This is a retrospective two-center study of patients who underwent percutaneous LAAO following LAAI. Patients with at least 3-month follow-up were included in the study. The antithrombotic therapy and TE events at the time of the last follow-up were noted. Results The LAA was successfully occluded in 162 (with Watchman device in 140 [86.4%] and Lariat in 22 [13.6%]). A total of 32 patients had leaks detected on the 45-day transesophageal echocardiogram (TEE); 21 (15%) Watchman and 11 (50%) Lariat cases (P = 0.0001). Two (one Watchman and one Lariat) of the 32 leaks were more than 5 mm. After the 45-day TEE, 150 (92.6%) patients were off-OAC. No TE events were reported in the 150 patients who stopped the anticoagulants. Four (2.47%) patients experienced stroke following the LAAO (three Watchman and one Lariat) procedure while on-OAC, two of which were fatal. At the median follow-up of 18.5 months, 159 (98.15%) patients were off-anticoagulant. Conclusion Up to 98% of patients with LAAI could safely discontinue OAC after undergoing the appendage closure procedure.

Aims The use of left atrial appendage (LAA)-occluders in atrial fibrillation is increasing. There are few data on the comparison between transesophageal echocardiography (TEE) and computed tomography (MDCT) assessing peridevice-flow and outcome of electrical cardioversion (ECV) in these patients. Methods and results Single-center prospective registry from 2009 to 2015 including all LAA-occluders to analyze success and complications during implantation and follow-up. Patients having ≥1 ECV were further analyzed. TEE was performed during implantation and at 6weeks. In a subgroup of 77patients, we compared MDCT with TEE at 6weeks. Overall, 135patients (69±9years; 70% male; CHA2DS2-VASc score: 3.6±1.4; HAS-BLED score: 2.5±0.6) received a LAA-occluder (Watchman, n = 73; ACP-1, n = 59; Amulet, n = 3; PVI+LAA-occluder, n = 91 and LAA-occluder-only, n = 44). Device implantation was successful in 131 (97%). Eight patients (5.9%) had major periprocedural complications (ischemic stroke/transient ischemic attacks, n = 4, tamponade, n = 2, device thrombosis, n = 2, Dressler syndrome, n = 1). The periprocedural complication rate was similar between concomitant procedure and LAA-occluder-only (8/91 vs. 5/44; p = 0.6). Twelve patients (9%) died (procedure-related, n = 2; 1%) during follow-up of 44 months (IQR:43). MDCT (n = 77) at 6weeks showed similar peridevice-flow compared to TEE (TEE: 1.5±1.9mm vs. MDCT: 1.1± 2.2mm, p = 0.25. Thromboembolic events occurred in 3patients (CVA, n = 1;TIA, n = 2) during follow-up. In total, 41 ECV were performed in 26 patients (1.6±0.9/pt) 13 months (IQR: 24) after implantation (

Dabigatran versus Warfarin for AF AblationBackground Uninterrupted oral anticoagulant (OA) therapy with warfarin has become the standard of care at many centers performing catheter ablation of atrial fibrillation (AF). Compared with warfarin, dabigatran, a direct thrombin inhibitor, has been demonstrated to reduce the risk of stroke in nonvalvular AF with similar bleeding risk. Few data exist on the safety profile of uninterrupted dabigatran therapy during AF ablation. Methods We compared the safety and efficacy of uninterrupted OA therapy with either warfarin or dabigatran in all patients undergoing AF catheter ablation at the University of Alabama at Birmingham between November 1, 2010 and January 31, 2012. All patients underwent a transesophageal echocardiogram (TEE) on the day of their ablation procedure to assess for the presence of intracardiac thrombi. All complications were identified and classified as bleeding, thromboembolic events, or other. Results There were 212 patients in the dabigatran group and 251 patients in the warfarin group. The groups were well matched. There were 3 complications in the dabigatran group and 6 in the warfarin group (P = 0.45). There were 2 bleeding complications in the dabigatran group and 6 in the warfarin group (P = 0.23). There was one thromboembolic complication (a possible TIA) in the dabigatran group and none in the warfarin group (P = 0.28). Conclusion The administration of dabigatran is as safe and effective as warfarin for uninterrupted OA therapy during catheter ablation of AF.

Incomplete LAA Occlusion by WATCHMAN Device. Introduction: Transcatheter left atrial appendage (LAA) closure with the WATCHMAN device has become one of the therapeutic options in atrial fibrillation (AF) patients who are at high risk for ischemic stroke. However, the incidence and evolution of incomplete occlusion of the LAA during and after placement of the WATCHMAN device has not been reported. Methods and Results: Fifty-eight consecutive patients who had undergone WATCHMAN device implant were included in the study. Intraprocedural, 45-day and 12-month transesophageal echocardiogram images were reviewed and analyzed. Peridevice gap was noted in 16 (27.6%), 17 (29.3%), and 20 (34.5%) patients across the 3 time points. Intraprocedural gaps are more likely to be persistent until 12 months and become larger in size over time. New gap also occurs during follow-up even if the LAA was completely sealed at implantation. One patient had an ischemic stroke 4.7 months after implant; another patient developed a left atrial thrombus over the device 21.6 months after implant. Both patients had intraprocedural gap and discontinued warfarin therapy after the 45-day evaluation. Conclusion: Incomplete LAA occlusion with a gap between the WATCHMAN device surface and the LAA wall is relatively common. Intraprocedural gaps are more likely to become bigger over time and persist, while new gaps also occur during follow-up. Further studies are warranted to verify whether the presence and persistence of a peridevice gap is associated with increased risk of thromboembolic event in AF patients implanted with a WATCHMAN device. (J Cardiovasc Electrophysiol, Vol. 23, pp. 455-461, May 2012)

Introduction: Multidetector CT (MDCT) is used prior to atrial fibrillation ablation (AFA) to anatomically guide ablation procedures. Whether 64-slice MDCT also can be used to diagnose left atrial thrombus is not known. Methods: We sought to determine the accuracy and interobserver variability of MDCT in the evaluation of left atrial thrombus prior to AFA. We enrolled 50 patients scheduled for AFA who underwent 64-slice MDCT scan and transesophageal echocardiography prior to the procedure. Three experienced observers reviewed all the MDCT images for the presence of a left atrial thrombus, and two different readers interpreted the transesophageal echocardiograms (TEE), which were used as the gold standard. All observers were blinded to clinical data and each other. Results: Interobserver variability between the three MDCT readers was poor (highest kappa statistic 0.43, P = 0.001). Diagnostic accuracy was highly variable, with sensitivities ranging from 100% to 50% and specificities ranging from 85% to 44%. TEE reader agreement was 98%. Conclusion: MDCT demonstrates high interobserver variability and has only modest diagnostic accuracy for the detection of left atrial thrombus in patients undergoing AFA procedure. Potential factors affecting the accuracy of MDCT include image quality and the difficulty of distinguishing clot from pectinate muscle. MDCT likely is not the optimal method to detect left atrial thrombus using current techniques and standards of interpretation.

The optimal management of a patient with new-onset atrial fibrillation (AF) is highly individualized. Frequently, the key management decision is whether or not to perform acute cardioversion. This decision involves asking two questions: (1) should cardioversion be performed at all? And, if so, (2) should cardioversion be performed acutely or should it be delayed? To answer the first question, the benefits of sinus rhythm, the risks of cardioversion, and the likelihood of recurrence must be considered. The answer to the second question depends largely on the duration of AF. In patients who have had AF for 48 hours, or in whom the duration is unclear, an atrial thrombus must be excluded by a transesophageal echocardiogram (TEE) if acute cardioversion is being considered, unless the situa

Ablation of Focal AF. Introduction: Several reports have demonstrated that focal atrial fibrillation (AF) may arise from pulmonary veins (PVs). The purpose of this study was to investigate the safety and efficacy of using double multielectrode mapping catheters in ablation of focal AF. Methods and Results: Forty-two patients (30 men, 12 women, age 65 ± 14 years) with frequent attacks of paroxysmal AF were referred for catheter ablation. After atrial transseptal procedure, two long sheaths were put into the left atrium. Two decapolar catheters were put into the right superior PV (RSPV) and left superior PV (LSPV), or inferior PVs if necessary, guided by pulmonary venography. All the patients had spontaneous initiation of AF either during baseline (2 patients), after isoproterenol infusion (8 patients) or high-dose adenosine (2 patients), after short duration burst pacing under isoproterenol (14 patients), or after cardioversion of pacinginduced AF (16 patients). The trigger points of AF were from the LSPV (12 patients), RSPV (8 patients), and both superior PVs (19 patients). The trigger points from PVs (total 61 points) were 18 (30%) in the ostium of PVs and 43 inside the PVs (9 to 40 mm). After 6 ± 3 applications of radiofrequency energy, 57 of 61 triggers were completely eliminated, and the other 4 triggers were partially eliminated. During a follow-up period of 8 ± 2 months, 37 patients (88%) were free of symptomatic AF without any antiarrhythmic drugs. Twenty patients received a transesophageal echocardiogram, and 19 showed small atrial septal defects (2.8 ± 1.2 mm) with trivial shunt. Fifteen defects closed spontaneously 1 month later. Conclusion: The technique using double multielectrode mapping catheters is a relatively safe and highly effective method for mapping and ablation of focal AF originating from PVs.

Use of Balloon Atrial Septostomy. Introduction: With the increasing number of patients undergoing repeat catheter ablation procedures for atrial fibrillation, it is not uncommon to encounter a fibrotic interatrial septum that resists the conventional manual advancement of the transseptal sheath. Forceful advancement of the transseptal apparatus can reduce fine control and potentially lead to a higher rate of perforation. Case: We report a case where adjunctive balloon atrial septostomy was used to facilitate transseptal access in a patient with fibrotic interatrial septum. Using a small-caliber angioplasty balloon and under direct fluoroscopic and transesophageal echocardiogram visualization, balloon septostomy was performed with hand inflation until a “waist” was seen. This technique provides a safe way to control the size of the transseptal access created, and allows the passage of a relatively soft-tipped transseptal sheath across a resistive septum. To our knowledge this is the first published use of balloon atrial septostomy during transseptal puncture for left atrium access in a catheter ablation procedure. Conclusion: Balloon atrial septostomy should be considered as an alternative technique for safe transseptal cannulation in select patients in the electrophysiology laboratory or other interventional procedures requiring left atrial access or delivery of large-caliber catheters or sheaths. (J Cardiovasc Electrophysiol, Vol. 22, pp. 822-824, July 2011)

LAA Thrombus Among Anticoagulated AF Patients. Introduction: Catheter-directed atrial fibrillation (AF) ablation is contraindicated among patients with left atrial appendage (LAA) thrombus. The prevalence of LAA thrombus among fully anticoagulated patients undergoing AF ablation is unknown. Methods and Results: We retrospectively evaluated the prevalence of LAA thrombus among 192 consecutive patients undergoing AF ablation between July 2006 and January 2009. Seven of 192 patients (3.6%) had evidence of thrombus on transesophageal echocardiogram (TEE) despite being fully anticoagulated on warfarin (international normalized ratio [INR] 2–3) for 4 consecutive weeks prior to echocardiogram. Univariate analysis demonstrated that structural heart disease, large left atrial dimension, and number of AF ablations were associated with thrombus. Three patients with thrombus had paroxysmal AF with normal LV function. Conclusion: Despite full anticoagulation, 3.6% of patients undergoing AF ablation had LAA thrombus. We recommend that all patients, regardless of LV function or left atrial size, should undergo preprocedural TEE to exclude the presence of LAA thrombus. (J Cardiovasc Electrophysiol, Vol. 21, pp. 849-852, August 2010)

Background: Thromboembolic complications during left-sided ablations range between 1.5 and 5.4%. Preprocedural TEE has been used to exclude the presence of left atrial thrombi in order to minimize risk. The use of TEE is empiric and it has not been evaluated in contemporary practice. Methods and Results: A multicenter national survey describing the practice at 11 Canadian teaching hospitals. A total of 2,225 patients underwent elective catheter ablation for symptomatic AF. Transesophageal echocardiography (TEE) was used either routinely or selectively as a preablative strategy in patients. There were 996 patients in a routine preprocedure TEE strategy and 1,190 in a selected TEE strategy; 1 center (n = 39 patients) did not perform TEE. Twelve of 996 (1.2%) in the routine unselected cohort had thrombi identified. TEEs were performed in 200 of 1,190 in the selected cohort; 4 (2.0%) left atrial thrombi were observed; there was no significant difference in the prevalence of thrombi (P = 0.34). A total of 11 embolic events occurred inclusive of all groups. There was no difference in event rates between the 2 strategies (0.6% and 0.4%, P = 0.54). Events were unrelated to AF duration (persistent vs paroxysmal, r = 0.03, N = 2,225, P = 0.9). Conclusion: The selection criteria employed to perform TEEs did not increase the chance of identifying LA thrombi in a patient cohort with primarily nondilated left atria and paroxysmal AF. The overall thromboembolic event rate was low (0.49%) and was not significantly different between the 2 TEE strategies.