- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.