When and how to target atrial fibrillation sources outside the pulmonary veins: A practical approachPulmonary 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.
Pulmonary vein signal interpretation during cryoballoon ablation for atrial fibrillationThe 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.