Wavefront direction and cycle length affect left atrial electrogram amplitude.

Background: The relationship between atrial electrogram (EGM) characteristics in atrial fibrillation (AF) and those in sinus rhythm (SR) are generally unknown. The activation rate and direction may affect EGM characteristics. We examined characteristics of left atrial (LA) EGMs obtained during pacing from different sites.

Complex fractionated atrial electrograms, high dominant frequency regions, and left atrial voltages during sinus rhythm and atrial fibrillation.

Background: Ablation targeting complex fractionated atrial electrograms (CFAEs) or high dominant frequency (DF) sites is generally effective for persistent atrial fibrillation (AF). CFAEs and/or high DF sites may exist in low-voltage regions, which theoretically represent abnormal substrates. However, whether CFAEs or high DF sites reflect low voltage substrates during sinus rhythm (SR) is unknown.

Anatomical proximity between ganglionated plexi and epicardial adipose tissue in the left atrium: implication for 3D reconstructed epicardial adipose tissue-based ablation.

Purpose: We sought to better understand the association between and clinical implications of ganglionated plexi (GPs), epicardial adipose tissue (EAT) in the left atrium (LA), and the initiation and maintenance of atrial fibrillation (AF).

Methods: Three-dimensional (3D) computed tomography (CT) reconstruction images of the LA, PVs, and LA-EAT were merged with the LA geometry for 25 with paroxysmal AF (PAF) and 15 with persistent AF (PerAF) scheduled for ablation. High-frequency stimulation (20 Hz, 25 mA, 10 ms) was performed at three sites within each of the five major anatomical LA GPs (superior left, inferior left, anterior right, inferior right, and Marshall tract GPs) to elicit vagal responses.

Localized rotors and focal impulse sources within the left atrium in human atrial fibrillation: A phase analysis of contact basket catheter electrograms.

Background: Consistent detection of rotor(s) and/or focal impulse(s) of atrial fibrillation can using a 64-pole basket catheter remain unclear.

Methods And Results: Intracardiac left atrial electrograms were recorded, prior to ablation, in 20 patients with atrial fibrillation. Unipolar electrograms, filtered at 0.

Effects of a high-fat diet on the electrical properties of porcine atria.

Background: Because obesity is an important risk factor for atrial fibrillation (AF), we conducted an animal study to examine the effect of a high-fat diet (HFD) on atrial properties and AF inducibility.

Methods: Ten 8-week-old pigs (weight, 18-23 kg) were divided into two groups. For 18 weeks, five pigs were fed a HFD (HFD group) and five were fed a normal diet (control group).

Effect of cryoballoon inflation at the right superior pulmonary vein orifice on phrenic nerve location.

Background: Cryoballoon catheter ablation was developed to simplify ablation for atrial fibrillation (AF). Initial enthusiasm for its widespread use has been dampened by phrenic nerve (PN) injury (PNI).

Objective: The purpose of this study was to assess the effect of cryoballoon inflation at the right superior pulmonary vein (RSPV) orifice on PN location and to elucidate the potential mechanism of PNI.

Frequency analysis of atrial fibrillation from the specific ECG leads V7-V9: A lower DF in lead V9 is a marker of potential atrial remodeling.

Introduction: High dominant frequency (DF) sites during atrial fibrillation (AF) play an important role in the perpetuation of AF. We investigated the relationship between the DFs from intracardiac electrograms (iEGM) and the surface electrocardiogram (ECG) during AF, and the relationship between the surface ECG DF and atrial remodeling.

Methods: In 48 patients (57±11 years, 47 males, 20 paroxysmal), the V1-6 precordial leads and specific V7-9 ECG leads were recorded for 8s for an off-line analysis before AF ablation.

Comparative distribution of complex fractionated atrial electrograms, high dominant frequency (HDF) sites during atrial fibrillation and HDF sites during sinus rhythm.

Purpose: Complex fractionated atrial electrograms (CFAEs) and high dominant frequency sites during atrial fibrillation (AF-HDF) are related to the maintenance of atrial fibrillation (AF). HDF sites in sinus rhythm (SR-HDF; as defined by frequencies of >70 Hz) are suggested to be abnormal atrial tissue. Relations between these electrophysiologic signals have not been elucidated.

Does location of epicardial adipose tissue correspond to endocardial high dominant frequency or complex fractionated atrial electrogram sites during atrial fibrillation?

Background: Although increased epicardial adipose tissue (EAT) volume is known to be associated with increased prevalence of atrial fibrillation (AF), the exact mechanisms are unclear. Therefore, we investigated whether EAT locations were associated with high dominant frequency (DF) sites or complicated fractionated atrial electrogram sites during AF.

Methods And Results: Three-dimensional reconstruction computed tomography images depicting EAT volumes (obtained by 320-detector-row multislice computed tomography) were merged with NavX-based DF and complicated fractionated atrial electrogram maps obtained during AF for 16 patients with paroxysmal AF and for 18 patients with persistent AF.

A quantitative and qualitative analysis of the virtual unipolar electrograms from non-contact mapping of right or left-sided outflow tract premature ventricular contractions/ventricular tachycardia origins.

Objective: This study was conducted to examine the virtual unipolar electrogram configuration of right/left outflow tract (OT) premature ventricular contraction (PVC)/ventricular tachycardia (VT) origins obtained from a non-contact mapping system (NCMS).

Methods: The subjects consisted of 30 patients with OT-PVCs/VT who underwent NCMS-guided ablation. We evaluated the virtual unipolar electrograms of the origin on 3D right ventricular (RV)-OT isochronal maps.