Pulmonary Vein Isolation With or Without Left Atrial Appendage Ligation in Atrial Fibrillation: The aMAZE Randomized Clinical Trial.

Importance: Left atrial appendage elimination may improve catheter ablation outcomes for atrial fibrillation. Objective: To assess the safety and effectiveness of percutaneous left atrial appendage ligation adjunctive to catheter pulmonary vein isolation for nonparoxysmal atrial fibrillation. Design, Setting, and Participants: This multicenter, prospective, open-label, randomized clinical trial evaluated the safety and effectiveness of percutaneous left atrial appendage ligation adjunctive to planned pulmonary vein isolation for nonparoxysmal atrial fibrillation present for less than 3 years. Eligible patients were randomized in a 2:1 ratio to undergo left atrial appendage ligation and pulmonary vein isolation or pulmonary vein isolation alone. Use of a 2:1 randomization ratio was intended to provide more device experience and safety data. Patients were enrolled from October 2015 to December 2019 at 53 US sites, with the final follow-up visit on April 21, 2021. Interventions: Left atrial appendage ligation plus pulmonary vein isolation compared with pulmonary vein isolation alone. Main Outcomes and Measures: A bayesian adaptive analysis was used for primary end points. Primary effectiveness was freedom from documented atrial arrythmias of greater than 30 seconds duration 12 months after undergoing pulmonary vein isolation. Rhythm was assessed by Holter monitoring at 6 and 12 months after pulmonary vein isolation, symptomatic event monitoring, or any electrocardiographic tracing obtained through 12 months after pulmonary vein isolation. Primary safety was a composite of predefined serious adverse events compared with a prespecified 10% performance goal 30 days after the procedure. Left atrial appendage closure was evaluated through 12 months after pulmonary vein isolation. Results: Overall, 404 patients were randomized to undergo left atrial appendage ligation plus pulmonary vein isolation and 206 were randomized to undergo pulmonary vein isolation alone. Primary effectiveness was 64.3% with left atrial appendage ligation and pulmonary vein isolation and 59.9% with pulmonary vein isolation only (difference, 4.3% [bayesian 95% credible interval, -4.2% to 13.2%]; posterior superiority probability, 0.835), which did not meet the statistical criterion to establish superiority (0.977). Primary safety was met, with a 30-day serious adverse event rate of 3.4% (bayesian 95% credible interval, 2.0% to 5.0%; posterior probability, 1.0) which was less than the prespecified threshold of 10%. At 12 months after pulmonary vein isolation, complete left atrial appendage closure (0 mm residual communication) was observed in 84% of patients and less than or equal to 5 mm residual communication was observed in 99% of patients. Conclusions and Relevance: Percutaneous left atrial appendage ligation adjunctive to pulmonary vein isolation did not meet prespecified efficacy criteria for freedom from atrial arrhythmias at 12 months compared with pulmonary vein isolation alone for patients with nonparoxysmal atrial fibrillation, but met prespecified safety criteria and demonstrated high rates of closure at 12 months. Trial Registration: ClinicalTrials.gov Identifier: NCT02513797.

Novel streamlined technique for left atrial appendage closure using a radiofrequency wire-based large access system.

INTRODUCTION: Transseptal puncture (TSP) to allow for large delivery sheath left atrial (LA) access remains a challenging aspect of LA appendage closure (LAAC) in patients with prior history of TSP, thick or lipomatous septum, atrial septal aneurysms, or other complex cardiac anatomies. This study investigates the use of the VersaCross large access (VLA) system (Baylis Medical/Boston Scientific) to improve procedural efficiency of LAAC compared to the standard needle workflow. METHODS AND RESULTS: Fifty LAAC procedures using WATCHMAN FLX between November 2021 and September 2022 were retrospectively analyzed comparing the VLA workflow (n = 25) to the standard needle workflow (n = 25). Study primary endpoint was time to procedural efficiency, and secondary endpoints included TSP time, acute LAAC success, fluoroscopy use, device recaptures, and periprocedural complications. Acute LAAC was successfully completed in all cases with no intraprocedural complications. TSP time was faster, but not significant, using the VLA workflow compared to the standard RF needle workflow (2.6 ± 1.1 min vs. 3.0 ± 1.8 min, p = 0.38). Time to WATCHMAN sheath in LA from TSP was 27% faster (1.5 ± 0.8 min vs. 2.1 ± 0.9 min; p = 0.03), and time to WATCHMAN release from TSP was 19% faster (10.5. ± 2.5 min vs. 13.0 ± 3.7 min; p = 0.01) with the VLA workflow. Overall procedure time was 15% faster (30.4 ± 5.1 min vs. 36.0 ± 6.6 min; p = 0.003) using VLA. Fluoroscopy time was 25% lower (4.0 ± 2.2 min vs. 5.5 ± 2.3 min; p = 0.003) and fluoroscopy dose was 60% lower (97.0 ± 91.7 mGy vs. 241.8 ± 240.6 mGy; p = 0.01) and more consistent [F-test, p ˂ 0.0001] using the VLA workflow compared to the needle workflow. CONCLUSION: The VLA system streamlines LAAC procedures, improving LAAC efficiency and reducing fluoroscopy use by allowing for de novo dilation of the septum for large-bore delivery sheaths, and reducing device exchanges and delivery sheath manipulation.

Three-dimensional intracardiac echocardiography for left atrial appendage sizing and percutaneous occlusion guidance.

AIMS: Left atrial appendage (LAA) imaging is critical during percutaneous occlusion procedures. 3D-intracardiac echocardiography (ICE) features direct visualization of LAA from multiple cross-sectional planes at a time. We aimed at reporting procedural success of 3D-ICE-guided LAA occlusion and the correlation between pre-procedural transoesophageal echocardiography (TEE) and intraprocedural 3D-ICE for LAA sizing. METHODS AND RESULTS: Among 274 patients undergoing left atrial appendage occlusion (LAAO) with a Watchman FLX, periprocedural ICE guidance was achieved via a commercially available 2D-ICE catheter (220 patients) or a novel (NUVISION™) 3D-ICE one (54 patients). Primary endpoint was a composite of procedural success and LAA sealing at follow-up TEE. Secondary endpoint was a composite of periprocedural device recapture/resizing plus presence of leaks ≥ 3 mm at follow-up TEE. 3D-ICE measurements of maximum landing zone correlated highly with pre-procedural TEE reference values [Pearson's: 0.94; P < 0.001; bias: -0.06 (-2.39, 2.27)]. The agreement between 3D-ICE-based device selection and final device size was 96.3% vs. 79.1% with 2D-ICE (P = 0.005). The incidence of the primary endpoint was 98.1% with 3D-ICE and 97.3% with 2D-ICE (P = 0.99). 2D-ICE patients had a trend towards a higher incidence of periprocedural device recapture/redeployment (31.5% vs. 44.5%; P = 0.09). The secondary endpoint occurred in 31.5% of 3D-ICE patients vs. 45.9% of 2D-ICE ones (P = 0.065). CONCLUSION: Intracardiac echocardiography-guided LAAO showed a very high success, with no major adverse events. A very high level of agreement for LAA sizing was found between pre-procedural TEE and periprocedural 3D-ICE. 3D-ICE performed significantly better than 2D-ICE for FLX size selection and may provide better guidance during device deployment.

Atrial fibrillation symptom reduction and improved quality of life following the hybrid convergent procedure: a CONVERGE trial subanalysis.

Background: CONVERGE was a prospective, multicenter, randomized controlled trial that evaluated the safety of Hybrid Atrial Fibrillation Convergent (HC) and compared its effectiveness to endocardial catheter ablation (CA) for the treatment of persistent atrial fibrillation (PersAF) and longstanding PersAF (LSPAF). In 2020, we reported that CONVERGE met its primary safety and effectiveness endpoints. The primary objective of the present study is to report CONVERGE trial results for quality of life (QOL) and Class I/III anti-arrhythmic drug (AAD) utilization following HC. Methods: Eligible patients had drug-refractory symptomatic PersAF or LSPAF and a left atrium diameter ≤6.0 cm. Enrolled patients were randomized 2:1 to receive HC or CA. Atrial Fibrillation Severity Scale (AFSS) and the 36-Item Short Form Health Survey (SF-36) were assessed at baseline and 12 months; statistical comparison was performed using paired t-tests. AAD utilization at baseline through 12 and 18 months post-procedure was evaluated; statistical comparison was performed using McNemar's tests. Results: A total of 153 patients were treated with either HC (n=102) or CA (n=51). Of the 102 HC patients, 38 had LSPAF. AFSS and SF-36 Mental and Physical Component scores were significantly improved at 12 months versus baseline with HC overall and for the subset of LSPAF patients treated with either HC or CA. The proportion of HC patients (n=102) who used Class I /III AADs at 12 and 18 months was significantly less (33.3% and 36.3%, respectively) than baseline (84.3%; P<0.001). In LSPAF patients who underwent HC (n=38), AADs use was 29.0% through 18 months follow-up versus 71.1% at baseline (P<0.001). Conclusions: HC reduced AF symptoms, significantly improved QOL, and reduced AAD use in patients with PersAF and LSPAF. ClinicalTrialsgov Identifier: NCT01984346.

Creating a safe workplace by universal testing of SARS-CoV-2 infection in asymptomatic patients and healthcare workers in the electrophysiology units: a multi-center experience.

BACKGROUND: As the coronavirus cases continue to surge, the urgent need for universal testing to identify positive cases for effective containment of this highly contagious pandemic has become the center of attention worldwide. However, in spite of extensive discussions, very few places have even attempted to implement it. We evaluated the efficacy of widespread testing in creating a safe workplace in our electrophysiology (EP) community. Furthermore, we assessed the new infection rate in patients undergoing EP procedure, to see if identification and exclusion of positive cases facilitated establishment of a risk-free operating environment. METHODS: Viral-RNA and serology tests were conducted in 1670 asymptomatic subjects including patients and their caregivers and staff in our EP units along with the Emergency Medical Service (EMS) staff. RESULTS: Of 1670, 758 (45.4%) were patients and the remaining 912 were caregivers, EMS staff, and staff from EP clinic and lab. Viral-RNA test revealed 64 (3.8%) positives in the population. A significant increase in positivity rate was observed from April to June 2020 (p = 0.02). Procedures of positive cases (n = 31) were postponed until they tested negative at retesting. Staff testing positive (n = 33) were retested before going back to work after 2 weeks. Because of suspected exposure, 67 staff were retested and source was traced. No new infections were reported in patients during or within 2 weeks after the hospital-stay. CONCLUSIONS: Universal testing to identify positive cases was helpful in creating and maintaining a safe working environment without exposing patients and staff to new infections in the EP units. TRIAL REGISTRATION: Trial Registration Number: clinicaltrials.gov : NCT04352764.

Subxiphoid Hybrid Epicardial-Endocardial Atrial Fibrillation Ablation and LAA Ligation: Initial Sub-X Hybrid MAZE Registry Results.

OBJECTIVES: The aim of this study was to assess the safety and efficacy of a new subxiphoid hybrid epicardial-endocardial atrial fibrillation (AF) ablation and left atrial appendage (LAA) ligation approach for the treatment of persistent AF. BACKGROUND: Surgical hybrid ablation procedures have shown promise for maintaining sinus rhythm versus catheter ablation but are associated with increased periprocedural adverse events. METHODS: Patients with symptomatic persistent AF (n = 33, mean age 64 ± 9 years, 25 men) who had antiarrhythmic drug therapy or prior catheter ablation was unsuccessful were referred for hybrid epicardial-endocardial AF ablation and LAA exclusion. LAA closure was confirmed by transesophageal echocardiographic Doppler flow and/or computed tomographic angiography 1 to 3 months post-ligation. The incidence of atrial tachycardia or AF recurrence, LAA closure, thromboembolic events, and post-operative complications were assessed. RESULTS: All 33 patients underwent successful LAA ligation with epicardial ablation of the posterior left atrial wall, as well as endocardial pulmonary vein isolation and cavotricuspid isthmus ablation. Freedom from atrial tachycardia or AF was 91% (20 of 22 patients) at 6 months, 90% (18 of 20 patients) at 12 months, 92% (11 of 12 patients) at 18 months, and 92% (11 of 12) at 24 months. There were no acute periprocedural complications (<7 days). Thirty-day adverse events included 2 patients with pericardial effusion requiring pericardiocentesis and 1 incisional hernia repair. There were no long-term complications, strokes, or deaths. LAA ligation was complete in 27 of 33 subjects (82%), with 6 subjects having leaks of <5 mm. CONCLUSIONS: Subxiphoid hybrid epicardial-endocardial ablation with LAA ligation is feasible, safe, and effective. Future prospective studies are needed to validate these initial findings.

Hybrid Convergent Procedure for the Treatment of Persistent and Long-Standing Persistent Atrial Fibrillation: Results of CONVERGE Clinical Trial.

BACKGROUND: The limited effectiveness of endocardial catheter ablation (CA) for persistent and long-standing persistent atrial fibrillation (AF) treatment led to the development of a minimally invasive epicardial/endocardial ablation approach (Hybrid Convergent) to achieve a more comprehensive lesion set with durable transmural lesions. The multicenter randomized controlled CONVERGE trial (Convergence of Epicardial and Endocardial Ablation for the Treatment of Symptomatic Persistent AF) evaluated the safety of Hybrid Convergent and compared its effectiveness to CA for persistent and long-standing persistent AF treatment. METHODS: One-hundred fifty-three patients were randomized 2:1 to Hybrid Convergent versus CA. Primary effectiveness was freedom from AF/atrial flutter/atrial tachycardia absent new/increased dosage of previously failed/intolerant class I/III antiarrhythmic drugs through 12 months. Primary safety was major adverse events through 30 days. CONVERGE permitted left atrium size up to 6 cm and imposed no limits on AF duration, making it the only ablation trial to substantially include long-standing persistent-AF, that is, 42% patients with long-standing persistent-AF. RESULTS: Of 149 evaluable patients at 12 months, primary effectiveness was achieved in 67.7% (67/99) patients with Hybrid Convergent and 50.0% (25/50) with CA (P=0.036) on/off previously failed antiarrhythmic drugs and in 53.5% (53/99) versus 32.0% (16/50; P=0.0128) respectively off antiarrhythmic drugs. At 18 months using 7-day Holter, 74.0% (53/72) Hybrid Convergent and 55% (23/42) CA patients experienced ≥90% AF burden reduction. A total of 2.9% (3/102) patients had primary safety events within 7 days, and 4.9% (5/102) between 8 and 30 days postprocedure. No deaths, cardiac perforations, or atrioesophageal fistulas occurred. All but one primary safety event resolved. CONCLUSIONS: The Hybrid Convergent procedure has superior effectiveness compared to the CA for the treatment of persistent and long-standing persistent atrial fibrillation. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01984346.

Characteristics of cavotricuspid isthmus-dependent atrial flutter after left atrial ablation of atrial fibrillation.

BACKGROUND: Patients who have previously undergone ablation of atrial fibrillation may experience cavotricuspid isthmus (CTI)-dependent atrial flutter during follow-up. The effects of left atrial (LA) ablation on the characteristics of CTI-dependent flutter have not been described. METHODS AND RESULTS: Fifteen patients underwent ablation of CTI-dependent flutter late after LA ablation of AF. The ECG, biatrial activation patterns, and LA voltage maps during flutter were analyzed. Thirty age- and gender-matched patients who underwent ablation of CTI-dependent flutter without prior LA ablation served as control subjects. Among the patients with prior LA ablation, mapping revealed counterclockwise activation around the tricuspid annulus in 12 of 15 patients (80%) and clockwise activation in 3 of 15 patients (20%). The flutter waves in the inferior leads were upright in 9 of the 15 patients (60%) with prior LA ablation and in none of the control subjects (P<0.001). The upright flutter waves in the inferior leads in patients with counterclockwise flutter corresponded to craniocaudal activation of the right atrial free wall. LA activation contributed little to the genesis of the flutter waves in these patients because of a significant reduction in bipolar LA voltage (0.44+/-0.20 versus 1.54+/-0.19 mV in patients with biphasic/negative flutter waves; P<0.001). CONCLUSIONS: CTI-dependent flutter that occurs after LA ablation of atrial fibrillation often has atypical ECG characteristics because of altered LA activation. In patients presenting with atrial flutter after LA ablation, entrainment mapping should be performed at the CTI even if the ECG is uncharacteristic of CTI-dependent flutter.

A tailored approach to catheter ablation of paroxysmal atrial fibrillation.

BACKGROUND: Because the genesis of atrial fibrillation (AF) is multifactorial and variable, an ablation strategy that involves pulmonary vein isolation and/or a particular set of ablation lines may not be equally effective or efficient in all patients with AF. A tailored strategy that targets initiators and drivers of AF is a possible alternative to a standardized lesion set. METHODS AND RESULTS: Catheter ablation was performed in 153 consecutive patients (mean age, 56+/-11 years) with symptomatic paroxysmal AF with the use of an 8-mm tip radiofrequency ablation catheter. The esophagus was visualized with barium. The pulmonary veins and left atrium were mapped during spontaneous or induced AF. Arrhythmogenic pulmonary veins were isolated or encircled. If AF was still present or inducible, complex electrograms in the left atrium, coronary sinus, and superior vena cava were targeted for ablation. The end point of ablation was absence of frequent atrial ectopy and spontaneous AF during isoproterenol infusion and noninducibility of AF. Routine energy applications near the esophagus were avoided. During follow-up, left atrial flutter developed in 19% of patients and was still present in 10% at >12 weeks of follow-up. A repeat ablation procedure was performed in 18% of patients. During a mean follow-up of 11+/-4 months, 77% of patients were free from AF and/or atrial flutter without antiarrhythmic drug therapy. Pericardial tamponade or transient neurological events occurred in 2% of procedures. CONCLUSIONS: A tailored ablation strategy that only targets triggers and drivers of AF is feasible and eliminates paroxysmal AF in approximately 80% of patients.

Risk of thromboembolic events after percutaneous left atrial radiofrequency ablation of atrial fibrillation.

BACKGROUND: In patients with atrial fibrillation (AF), the risk of thromboembolic events (TEs) is variable and is influenced by the presence and number of comorbid conditions. The effect of percutaneous left atrial radiofrequency ablation (LARFA) of AF on the risk of TEs is unclear. METHODS AND RESULTS: LARFA was performed in 755 consecutive patients with paroxysmal (n = 490) or chronic (n = 265) AF. Four hundred eleven patients (56%) had > or = 1 risk factor for stroke. All patients were anticoagulated with warfarin for > or = 3 months after LARFA. A TE occurred in 7 patients (0.9%) within 2 weeks of LARFA. A late TE occurred 6 to 10 months after ablation in 2 patients (0.2%), 1 of whom still had AF, despite therapeutic anticoagulation in both. Among 522 patients who remained in sinus rhythm after LARFA, warfarin was discontinued in 79% of 256 patients without risk factors and in 68% of 266 patients with > or = 1 risk factor. Patients older than 65 years or with a history of stroke were more likely to remain anticoagulated despite a successful outcome from LARFA. None of the patients in whom anticoagulation was discontinued had a TE during 25 +/- 8 months of follow-up. CONCLUSIONS: The risk of a TE after LARFA is 1.1%, with most events occurring within 2 weeks after the procedure. Discontinuation of anticoagulant therapy appears to be safe after successful LARFA, both in patients without risk factors for stroke and in patients with risk factors other than age > 65 years and history of stroke. Sufficient safety data are as yet unavailable to support discontinuation of anticoagulation in patients older than 65 years or with a history of stroke.

Catheter ablation of atypical atrial flutter and atrial tachycardia within the coronary sinus after left atrial ablation for atrial fibrillation.

OBJECTIVES: The goal of this study was to describe the prevalence and ablation of coronary sinus (CS) arrhythmias after left atrial ablation for atrial fibrillation (AF). BACKGROUND: The CS has been implicated in a variety of supraventricular arrhythmias. METHODS: Thirty-eight patients underwent mapping and ablation of atypical flutter that developed during (n = 5) or after (n = 33) ablation for AF. Also included were two patients with focal CS arrhythmias that occurred during an AF ablation procedure. A tachycardia was considered to be originating from the CS if the post-pacing interval in the CS matched the tachycardia cycle length and/or if it terminated during ablation in the CS. RESULTS: Among the 33 patients who developed atypical flutter late after AF ablation, 9 (27%) were found to have a CS origin. Overall, 16 of the 40 patients in this study had a CS arrhythmia. The tachycardia was macro-re-entrant in 14 patients (88%) and focal in two patients. Radiofrequency ablation with an 8-mm-tip catheter was successful in 15 patients (94%) without complication. In eight patients (50%), > or = 45 W was required for successful ablation. Thirteen of the 15 patients (87%) with a successful ablation acutely remained arrhythmia-free during 5 +/- 5 months of follow-up. CONCLUSIONS: The musculature of the CS serves as a critical component of the re-entry circuit in approximately 25% of patients with atypical flutter after ablation for AF. The CS may also generate focal atrial arrhythmias that may play a role in triggering and/or maintaining AF. Catheter ablation of these arrhythmias in the CS can be performed safely.

Comparison of mapping criteria for hemodynamically tolerated, postinfarction ventricular tachycardia.

BACKGROUND: Mapping criteria for hemodynamically tolerated, postinfarction ventricular tachycardia (VT) have been evaluated in only small series of patients. OBJECTIVES: The purpose of this study was to evaluate the utility of various mapping criteria for identifying a critical VT circuit isthmus in a post hoc analysis. METHODS: Ninety VTs (cycle length 491 +/- 84 ms) were mapped in 48 patients with a prior myocardial infarction. The mapping catheter was positioned within a protected area of the reentrant circuit of the targeted VTs at 176 sites. All sites showed concealed entrainment. The predictive values of the following mapping criteria for a successful ablation site were compared: discrete isolated potential during VT, inability to dissociate the isolated potential from the VT, endocardial activation time >70 ms, matching electrogram-QRS and stimulus-QRS intervals, VT termination without global capture during pacing, stimulus-QRS/VT cycle length ratio

Left atrial appendage ligation with the next generation LARIAT(+) suture delivery device: Early clinical experience.

BACKGROUND: The purpose of the study was to determine the efficacy and safety of left atrial appendage (LAA) closure with a micropuncture pericardial access approach and the new LARIAT(+) suture delivery device. METHODS: Seventy-two patients with atrial fibrillation were enrolled to undergo telescopic micropuncture pericardial access and percutaneous ligation of the LAA with the LARIAT(+) device. LAA closure was confirmed with transesophageal echocardiography (TEE) and contrast fluoroscopy immediately, then with TEE at 30days and 90days post-LAA ligation. Patients were monitored for 12months by an independent clinical research organization for adverse events, stroke, embolic events and death of any cause. RESULTS: 72 patients were screened for the LARIAT(+) procedure. Fourteen patients were screened failures (7 patients due to unfavorable anatomy and 7 patients with LAA thrombus). Fifty-eight patients underwent successful LAA ligation. All 58 patients had complete acute closure of the LAA. At 1month 52 of 54 patients (96.3%) had LAA closure, while at 3months 48 of 52 patients (92.3%) had LAA closure. There were no leaks greater than 3mm at both 1 and 3months. There were no device or procedural related complications, and only 1 30day adverse event involving late pericardial effusion. There were no strokes, embolic events or deaths after 12months. CONCLUSIONS: LAA closure with the micropuncture pericardial access approach and the LARIAT(+) device can be performed effectively with acceptably low periprocedural adverse events.

Short and long-term outcomes of percutaneous left atrial appendage suture ligation: Results from a US multicenter evaluation.

BACKGROUND: Published studies of epicardial ligation of left atrial appendage (LAA) have reported discordant results. OBJECTIVE: The purpose of this study was to delineate the safety and efficacy of LAA closure with the LARIAT device. METHODS: This is a multicenter registry of 712 consecutive patients undergoing LAA ligation with LARIAT at 18 US hospitals. The primary end point was successful suture deployment, no leak by intraprocedural transesophageal echocardiography (TEE), and no major complication (death, stroke, cardiac perforation, and bleeding requiring transfusion) at discharge. A leak of 2-5 mm on follow-up TEE was the secondary end point. RESULTS: LARIAT was successfully deployed in 682 patients (95.5%). A complete closure was achieved in 669 patients (98%), while 13 patients (1.8%) had a trace leak (<2 mm). There was 1 death related to the procedure. Ten patients (1.44%) had cardiac perforation necessitating open heart surgery, while another 14 (2.01%) did not need surgery. The risk of cardiac perforation decreased significantly after the introduction of a micropuncture (MP) needle for pericardial access. Delayed complications (pericarditis requiring >2 weeks of treatment with nonsteroidal anti-inflammatory drugs/colchicine and pericardial and pleural effusion after discharge) occurred in 34 (4.78%) patients, and the risk decreased significantly with the periprocedural use of colchicine. Follow-up TEE (n = 480) showed a leak of 2-5 mm in 6.5% and a thrombus in 2.5%. One patient had a leak of >5 mm. CONCLUSION: LARIAT effectively closes the LAA and has acceptable procedural risks with the evolution of the use of the micropuncture needle for pericardial access and the use of colchicine for mitigating the postinflammatory response associated with LAA ligation and pericardial access.

Randomized comparison of encircling and nonencircling left atrial ablation for chronic atrial fibrillation.

BACKGROUND: Left atrial (LA) circumferential ablation has been reported to eliminate atrial fibrillation (AF). Whether an ablation without encirclement of the pulmonary veins (PVs) is as effective as LA circumferential ablation is not clear. OBJECTIVES: The purpose of this study was to compare the efficacy of LA circumferential ablation and nonencircling linear ablation in patients with chronic AF. METHODS: Eighty patients with chronic AF were randomized to undergo LA circumferential ablation (n = 40) or nonencircling linear ablation (n = 40). In LA circumferential ablation, the PVs were encircled, with additional lines made in the mitral isthmus and posterior wall or roof. In nonencircling linear ablation, 4 +/- 1 ablation lines were created through areas of complex electrograms, with lines in the roof (38), anterior wall (36), septum (40), mitral isthmus (32), and posterior annulus (6). The endpoint of LA circumferential ablation and nonencircling linear ablation was voltage abatement. RESULTS: LA flutter occurred in 15% after LA circumferential ablation and in 18% after nonencircling linear ablation (P = .8). A repeat ablation procedure was performed for recurrent AF in 7 and 11 patients or for atrial flutter in 6 and 4 patients after LA circumferential ablation and nonencircling linear ablation, respectively (P = .8). At 9 +/- 4 months, the prevalence of AF was 28% in the LA circumferential ablation and 25% in the nonencircling linear ablation group (P = .8). Sixty-eight percent and 60% of patients were in sinus rhythm and free of AF and atrial flutter in the absence of antiarrhythmic drug therapy after LA circumferential ablation and nonencircling linear ablation, respectively (P = .5). There were no complications. CONCLUSION: Nonencircling linear ablation and LA circumferential ablation are equally efficacious in eliminating chronic AF. However, the advantage of nonencircling linear ablation is that it eliminates the need for ablation along the posterior wall of the LA. Therefore, nonencircling linear ablation may avoid the small but real risk of atrioesophageal fistula formation associated with LA circumferential ablation.

Topographic analysis of the coronary sinus and major cardiac veins by computed tomography.

BACKGROUND: The coronary sinus (CS) and its branches may play a role in the genesis of various arrhythmias. Applications of radiofrequency energy within the CS may be necessary. Atrio-esophageal fistula has been recognized as a complication of ablation along the posterior left atrial wall. OBJECTIVES: The purpose of this study was to describe the in vivo topographic anatomy of the CS, esophagus, and coronary arteries using computed tomography (CT). METHODS: Helical contrast CT of the heart with three-dimensional and endoscopic reconstructions was performed in 50 patients (28 men and 22 women; mean age 54 +/- 10 years). The images were reformatted to determine the relationships among the CS, adjacent blood vessels, and esophagus and to determine the nature and thickness of surrounding tissue layers. RESULTS: Mean CS ostium diameter was 12 +/- 4 mm, and mean thickness of the periosteal fat layer was 3 +/- 2 mm. In 40 of the 50 patients (80%), the esophagus was adjacent to the CS, starting 24 +/- 9 mm from the ostium, and remained in contact for a mean length of 7 +/- 5 mm. Mean thickness of the fat layer between the esophagus and CS was 1 +/- 1 mm, and mean thickness of the anterior wall of the esophagus was 3 +/- 2 mm. In 10 patients (20%), there was no contact between the esophagus and CS. In 40 patients (80%), the right coronary artery was less than 5 mm from the CS (minimum distance 1 +/- 1 mm) over a mean length of 17 +/- 11 mm. In all patients, the circumflex artery was less than 5 mm from the CS (minimum distance 1 +/- 0.4 mm) over a mean length of 16 +/- 9 mm in patients with right-dominant coronary circulation and over a mean length of 86 +/- 11 mm in patients with left-dominant coronary circulation. CONCLUSION: The CS often lies very close to the esophagus and coronary arteries. During radiofrequency energy ablation in the CS, caution should be exercised to prevent injury to surrounding structures.

Effect of left atrial circumferential ablation for atrial fibrillation on left atrial transport function.

BACKGROUND: The effects of left atrial (LA) circumferential ablation on LA function in patients with atrial fibrillation (AF) have not been well described. OBJECTIVES: The purpose of this study was to determine the effect of LA circumferential ablation on LA function. METHODS: Gated, multiphase, dynamic contrast-enhanced computed tomographic (CT) scans of the chest with three-dimensional reconstructions of the heart were used to calculate the LA ejection fraction (EF) in 36 patients with paroxysmal (n = 27) or chronic (n = 9) AF (mean age 55 +/- 11 years) and in 10 control subjects with no history of AF. Because CT scans had to be acquired during sinus rhythm, a CT scan was available both before and after (mean 5 +/- 1 months) LA circumferential ablation (LACA) in only 10 patients. A single CT scan was acquired in 8 patients before and in 18 patients after LACA ablation. Radiofrequency catheter ablation was performed using an 8-mm-tip catheter to encircle the pulmonary veins, with additional lines along the mitral isthmus and the roof. RESULTS: In patients with paroxysmal AF, LA EF was lower after than before LACA (21% +/- 8% vs 32 +/- 13%, P = .003). LA EF after LA catheter ablation was similar among patients with paroxysmal AF and those with chronic AF (21% +/- 8% vs 23 +/- 13%, P = .7). However, LA EF after LA catheter ablation was lower in all patients with AF than in control subjects (21% +/- 10% vs 47% +/- 5%, P < .001). CONCLUSION: During medium-term follow-up, restoration of sinus rhythm by LACA results in partial return of LA function in patients with chronic AF. However, in patients with paroxysmal AF, LA catheter ablation results in decreased LA function. Whether the impairment in LA function is severe enough to predispose to LA thrombi despite elimination of AF remains to be determined.

Surgical and concomitant epicardial-endocardial (hybrid) ablation of persistent and long-standing persistent atrial fibrillation.

Catheter ablation of atrial fibrillation (AF) has been shown to be effective for paroxysmal AF. However, for patients with persistent or longstanding persistent AF, the success rates for catheter ablation is low. The Cox-Maze procedure is the most effective non-pharmacological treatment of AF. However, due to the need for open-heart surgery and the morbidity associated with the surgical Cox-Maze procedure, minimally invasive and epicardial-endocardial (hybrid) ablation procedures have been developed. This article will review the main surgical and hybrid approaches used for the treatment of persistent and long-standing persistent AF.

Optimizing the detection of bidirectional block across the flutter isthmus for patients with typical isthmus-dependent atrial flutter.

The purpose of this study was to show that multipolar electrographic recordings along the subeustachian isthmus (SI) can better differentiate slow conduction from complete isthmus block after atrial flutter ablation, leading to a lower incidence of recurrent atrial flutter (Afl). Despite the presence of various techniques to identify bidirectional conduction block (BDB) after isthmus ablation for typical Afl, several studies, including a report from a national registry, suggest that radiofrequency ablation is still associated with a 15% recurrence rate. Thus, techniques that can distinguish slow conduction from complete isthmus block have the potential for reducing long-term recurrences. We evaluated patients who underwent radiofrequency ablation for typical isthmus-dependent Afl. Patients were separated into 2 groups. Group A underwent assessment of BDB with conventional methods. In group B, BDB was assessed by placing a multipolar catheter along the floor of the SI, pacing adjacent to the line of radiofrequency application, and assessing electrographic activation on either side. One hundred thirty-one cases of Afl ablation were analyzed (86 in group A, 45 in group B). Over a mean follow-up period of 17 months, recurrence rates of Afl were 16.5% in group A and 4.3% in group B (p = 0.043). Thus, assessment of BDB by placement of a multipolar catheter across the SI after ablation of typical Afl is associated with a significant reduction in long-term recurrence of Afl.