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Performing transcatheter left atrial appendage closure: Techniques and challenges
The left atrial appendage (LAA) has been demonstrated to be the major source of thromboemboli in patients with atrial fibrillation.1 The rationale of LAA closure is based on eliminating LAA continuity with the left atrium (LA), thereby reducing stroke risk. Indeed, left atrial appendage occlusion (LAAO) procedures play an important role in anticoagulation-intolerant patients who are at risk for atrial fibrillation–related stroke. Based on the PROTECT AF (Watchman Left Atrial Appendage System for Embolic PROTECTion in Patients With Atrial Fibrillation)2 and PREVAIL (Prospective Randomized Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation [AF] Versus Long Term Warfarin Therapy)3 studies, the Food and Drug Administration (FDA) approved use of the Watchman (Boston Scientific, Marlborough, MA) device in 2015, with an updated generation of device subsequently ratified in 2020 following the PINNACLE-FLX (Protection Against Embolism for Nonvalvular AF Patients: Investigational Device Evaluation of the Watchman FLX LAA Closure Technology) study.How to perform ethanol ablation of the vein of Marshall for treatment of atrial fibrillation
The arrhythmogenicity of the vein of Marshall (VoM) in atrial fibrillation (AF) has been known for more than 20 years.1 A recent randomized trial showed a reduced odds ratio (0.63; 95% confidence interval 0.41–0.97; P = .04) for the primary outcome of AF or atrial tachycardia (AT) recurrence in patients with persistent AF by adding VoM ethanol infusion (VoM-Et) to the standard ablation approach.2 The VoM is involved in 30% of ATs after AF ablation, and VoM ablation significantly improves the freedom from recurrent arrhythmia.How to perform left atrial appendage electrical isolation using radiofrequency ablation
Although pulmonary vein (PV) isolation (PVI) has been considered an effective treatment for paroxysmal atrial fibrillation (AF), non-paroxysmal AF is a complex arrhythmia for which no ablation strategy has been demonstrated to be effective and widely accepted. As such, a success rate of ∼55% in these patients with AF (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II [Star AF II trial]) is not acceptable in our opinion and efforts should be made to seek for alternative strategies.Evaluation of shortness of breath after atrial fibrillation ablation—Is there a stiff left atrium?
Ablation has emerged as the most effective therapy for atrial fibrillation (AF), with the primary goal to improve symptoms. However, there is a subset of patients who develop limiting symptoms after successful ablation despite reestablishment of sinus rhythm. There is now recognition of “stiff left atrial (LA) syndrome” related to adverse consequences of ablation itself on LA hemodynamics, as described by Gibson and others.1,2 Although relatively uncommon (1.4% incidence in the Gibson series), this syndrome is important to diagnose, as it can cause severe unexplained dyspnea.When and how to target atrial fibrillation sources outside the pulmonary veins: A practical approach
Pulmonary vein (PV) isolation is an effective procedure in patients with paroxysmal atrial fibrillation (AF). For most patients with persistent AF and a subset of patients with paroxysmal AF, however, PV isolation may not be sufficient. Patients with the persistent form are more often beleaguered with comorbidities, which result in a greater degree of structural alterations that contribute to the maintenance of AF. In addition, the atrial activation rate during AF is higher (as evidenced by a shorter AF cycle length) in patients with persistent AF, consistent with a greater degree of electrical remodeling.Fluoroless catheter ablation of atrial fibrillation
Although the concept of performing fluoroless catheter ablation of atrial fibrillation (AF) was introduced several years ago, it has yet to gain wide adoption.1,2 Despite its well-documented advantages, there are several impediments, including concern that a fluoroless approach will add time to the procedure and may require a second operator. However, perhaps the greatest obstacle is that many electrophysiologists are trained to rely on fluoroscopic imaging and are therefore reluctant to trust intracardiac echocardiography (ICE) as their primary visual modality for tracking catheter movement and manipulation.Pulmonary vein signal interpretation during cryoballoon ablation for atrial fibrillation
The recognition that paroxysmal atrial fibrillation (AF) is predominantly triggered by ectopic beats arising from the vicinity of pulmonary veins (PVs) has spurred the establishment of percutaneous procedures specifically designed to electrically sequestrate the arrhythmogenic PV from the vulnerable left atrium (LA) substrate.1 Recently, the procedure has evolved with the development of purpose-built pulmonary vein isolation (PVI) tools, such as the cryoballoon catheter. This article discusses the anatomic and electrophysiologic bases for the interpretation of pulmonary vein potentials (PVPs) using a small-caliber circular mapping catheter (CMC) and provides an expanded discussion on the pacing maneuvers relevant to cryoballoon-based PVI procedures.Prevention of phrenic nerve injury during interventional electrophysiologic procedures
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The advent of innovative, potent ablative technologies and the adoption of endo–epicardial approaches to treat various arrhythmias have engendered a need for developing strategies to prevent collateral damage to critical structures such as the phrenic nerve (PN) and the esophagus during percutaneous electrophysiologic interventions. Here we detail phrenic nerve injury (PNI) prevention strategies during atrial fibrillation (AF), atrial tachycardia (AT), and ventricular tachycardia (VT) ablation. PNI is more common on the right side because of the anatomic course of the nerve and the greater preponderance of AF and AT ablations.Safety and feasibility of transseptal puncture for atrial fibrillation ablation in patients with atrial septal defect closure devices
AF is often found in association with an ASD.1–4 There are an increasing number of patients undergoing transcatheter closure of an ASD who subsequently develop AF in clinical practice.2–4 Catheter ablation has emerged as an effective treatment strategy for drug-refractory symptomatic AF.5 While transseptal access to the left atrium (LA) is a prerequisite for AF ablation, it may prove difficult in the presence of an ASD closure device.6,7 Anticipating technical difficulties and potential complications may discourage operators from considering catheter ablation of AF in this particular patient population.How to perform antral pulmonary venous isolation using the cryoballoon
This article describes our current practice, clinical outcomes, and future directions for the use of balloon cryoablation for the treatment of atrial fibrillation.How to perform and interpret rotational angiography in the electrophysiology laboratory
Sophisticated imaging methods have been growing in popularity since the introduction of curative ablation procedures for atrial fibrillation (AF). This trend is predicated on the need for a precise anatomic guidance within the complex left atrial (LA) anatomy and less reliance on electrocardiographic characteristics of the substrate. Traditional two-dimensional imaging methods such as fluoroscopy would not satisfy the needs of a complex catheter navigation inside three-dimensional (3D) anatomic structures that may not be confined to the radiographic cardiac silhouette (e.g., pulmonary veins [PVs]).Novel ablative approach for atrial fibrillation to decrease risk of esophageal injury
Percutaneous atrial fibrillation (AF) ablation using catheter-delivered radiofrequency energy continues to improve in safety and effectiveness. Nonetheless, the potential risk of esophageal injury often limits the ability to fully ablate the posterior portion of the left atrium to achieve optimal procedural success without complications. We present a comprehensive approach that addresses this challenge. Our ablative strategies include (1) identifying the esophagus to minimize ablative energy, when possible, in the proximity of the esophagus, (2) maximize the ability of the esophagus to remove heat and to heal from potential thermal injury, and (3) optimizing energy delivery to avoid deep tissue injury while maintaining procedural efficacy.How to perform linear lesions
Atrial fibrillation (AF) is a particularly complex arrhythmia because the mechanisms leading to fibrillation are not fully understood. Accordingly, ablation strategies have evolved largely on an empirical basis. The creation of linear lesions is a fundamental strategy that is indispensable to an electrophysiology laboratory performing ablation for treatment of this arrhythmia.Pulmonary vein–related maneuvers: Part I
With the rapid evolution of atrial fibrillation ablation procedures, electrophysiologists have necessarily strived for simple and anatomic-based approaches. In all except the most straightforward procedures, however, questions regarding the significance of various potentials recorded on mapping and ablation catheters arise.1,2 Other articles in this series have described in detail the various approaches to atrial fibrillation ablation. In this article, the anatomic and electrophysiologic bases for pacing maneuvers used with a variety of ablation approaches are reviewed.How to determine and assess endpoints for left atrial ablation
Studies have demonstrated that myocardium surrounding pulmonary vein (PV) ostia plays an important role in the initiation and perpetuation of atrial fibrillation (AF).1,2 This important finding has led to the development of segmental PV ostial isolation, circumferential ablation, and isolation around the PVs using circular linear lesions guided by three-dimensional (3D) electroanatomic mapping. Substrate modification using limited linear ablation also has been demonstrated to improve the clinical outcome after PV isolation in patients with AF inducibility.How to recognize, manage, and prevent complications during atrial fibrillation ablation
Seminal observations by Haissaguerre et al1 demonstrating initiation of atrial fibrillation (AF) by pulmonary vein (PV) depolarizations led to the development of percutaneous catheter-based endocardial AF ablation procedure. Since its original description, the AF ablation procedure has evolved considerably. Currently, the most accepted ablation strategy involves creating circumferential radiofrequency (RF) ablation lesions around PV ostia (either individually or encircling wide areas around the left-sided and right-sided veins) with or without additional atrial lesions.
