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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., (Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Persistent and long-standing persistent atrial fibrillation (AF) often requires extensive and/or repeat radiofrequency (RF) ablation procedures., Objective: The Tailored Treatment of Persistent Atrial Fibrillation (TTOP-AF) study assessed the effectiveness and safety of the phased RF system in a randomized controlled comparison of medical therapy against phased RF ablation for the management of persistent and long-standing persistent AF., Methods: Patients who had failed at least 1 antiarrhythmic drug (AAD) were randomized (2:1) to ablation management (AM) or medical management (MM). AM patients were allowed up to 2 ablations. Index and retreatment procedures consisted of pulmonary vein isolation and ablation of complex fractionated atrial electrograms. MM patients received AAD changes and/or cardioversion. The primary end points of the TTOP-AF study included chronic effectiveness and safety at 6 months and acute safety within 7 days of ablation., Results: At 6 months, a greater proportion of AM patients achieved effectiveness off AAD (77 of 138 [55.8%]) compared to MM patients (19 of 72 [26.4%]) (P < .0001). Acutely, 92.8% (128/138) of the procedures were successful while 12.3% (17/138) experienced a serious procedure and/or device-related adverse event. The predefined acute safety end point was not met. The proportion of patients with chronic safety events did not differ significantly between groups., Conclusions: Catheter ablation of persistent/long-standing persistent AF with the phased RF ablation system is effective with greater reduction of AF compared with MM. More intense anticoagulation strategies, careful attention to catheter placement relative to the pulmonary vein ostia, and elimination of electrode interaction are expected to reduce the risk of stroke, pulmonary vein stenosis, and asymptomatic cerebral emboli., (© 2014 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.)

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

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.

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.