Impact of the Temporal Relationship Between Atrial Fibrillation and Heart Failure on Prognosis After Ablation.

Background: The purpose of this study was to elucidate the effect of the temporal relationship between atrial fibrillation (AF) and heart failure (HF) on clinical outcomes after catheter ablation.

Methods and results: We included 129 consecutive patients with AF and HF who underwent catheter ablation in hospital from December 2014 to September 2017. The patients were divided into 2 groups based on the temporal relationship between AF and HF.

Comparison of ablation outcomes of the second ablation procedure for recurrent atrial fibrillation using an ultra-high-resolution mapping system and conventional mappings system.

Background: The utility of an ultra-high-resolution electroanatomical mapping system (UHR-EAM, Rhythmia) for repeat atrial fibrillation (AF) ablation has not been evaluated.

Hypothesis: A second AF ablation procedure performed using UHR-EAM may demonstrate different outcomes compared with that using a conventional electroanatomical mapping system (C-EAM, CARTO3).

Method: This observational study enrolled consecutive patients who underwent a second AF ablation procedure using UHR-EAM (n = 103) and C-EAM (n = 153).

Usefulness of an I blocker for ablation of non-pulmonary vein ectopies that are unmappable due to easily initiated atrial fibrillation.

Purpose: When atrial fibrillation (AF) is initiated by a single or several non-pulmonary vein (PV) trigger ectopic beats, mapping the ectopy is often difficult, requiring a number of electrical cardioversion applications. Nifekalant is a rapidly activating delayed rectifier potassium channel (I) blocker which may suppress AF initiation without inhibiting ectopy development, thereby allowing the target ectopy to be mapped. To assess the efficacy of nifekalant in the ablation of non-PV ectopies that are unmappable due to easily initiated AF.

A decapolar 25-mm-diameter circular mapping catheter with improved detection of pulmonary vein potential disappearance in cryoballoon ablation.

Background: Disappearance of pulmonary vein (PV) potentials is an important indicator of successful PV isolation during cryoballoon ablation. Conventional octapolar 20-mm-diameter circular PV mapping catheters occasionally fail to identify persistent PV potentials. A new decapolar 25-mm-diameter circular PV mapping catheter has been introduced to improve the detection of PV potentials and their elimination.

Comparison of electrogram waveforms between a multielectrode mapping catheter and a linear ablation catheter.

Background: Smaller low-voltage areas (LVAs) obtained by multielectrode catheters were reported than those by linear ablation catheters. However, the underlying electrogram difference has not been elucidated. This study aimed to compare the two mapping catheters' measurements of electrogram waveforms and LVAs.

Impact of Renal Dysfunction on Left Atrial Low-Voltage Areas in Patients With Atrial Fibrillation.

Background: The presence of residual left atrial low-voltage areas (LVA) has been shown to be strongly associated with atrial fibrillation (AF) recurrence after pulmonary vein isolation. A preliminary study showed that concomitant chronic kidney disease (CKD) increased the rate of AF recurrence. The association between CKD and LVA, however, has not been elucidated.

Centrifugal Wave Front Propagation Speed for Localizing the Origin of Ventricular Arrhythmias: Investigation Using a New Ultra-High-Resolution Mapping System.

Objectives: The aim of this study was to assess the use of wave front propagation speed on a right ventricular map for determining the earliest activation site as the origin of outflow tract ventricular arrhythmias (VAs).

Background: VAs with centrifugal right ventricular outflow tract (RVOT) activation can be from an RVOT focus or a focus outside the RVOT.

Methods: This prospective observational study included 23 patients with idiopathic outflow tract VAs.

Left atrial low-voltage areas predict atrial fibrillation recurrence after catheter ablation in patients with paroxysmal atrial fibrillation.

Background: Association between the presence of left atrial low-voltage areas and atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) has been shown mainly in persistent AF patients. We sought to compare the AF recurrence rate in paroxysmal AF patients with and without left atrial low-voltage areas.

Methods: This prospective observational study included 147 consecutive patients undergoing initial ablation for paroxysmal AF.

The identification of conduction gaps after pulmonary vein isolation using a new electroanatomic mapping system.

Background: The reconnection of left atrial-pulmonary vein (LA-PV) conduction after the initial procedure of pulmonary vein (PV) isolation is not rare, and is one of the main cause of atrial fibrillation (AF) recurrence after PV isolation.

Objective: We investigated feasibility of a new ultrahigh-resolution mapping system using a 64-pole small basket catheter for the identification of LA-PV conduction gaps.

Methods: This prospective study included 31 consecutive patients (20 with persistent AF) undergoing a second ablation after a PV isolation procedure with LA-PV reconnected conduction at any of the 4 PVs.