title: Spectral turbulence analysis of the signal-averaged electrocardiogram of the atrial activation as predictor of recurrence of idiopathic and persistent atrial fibrillation.
abstract: The frequency domain analysis of the P-wave signal-averaged ECG (P-SAECG) is able to identify patients at risk for lone atrial fibrillation (AF) after cardioversion to sinus rhythm. The terminal portion of the P-wave of right precordial leads on 12-lead ECG is associated with electrical abnormalities in the atria. The aim of this study was to assess the spectral turbulence analysis (STA) of the P-SAECG as a predictor of recurrence of idiopathic AF. STA was performed in 41 patients with 2 or more symptomatic episodes of idiopathic and persistent AF after successful electrical cardioversion and drug-free state (Group A), and in 25 control individuals during sinus rhythm (Group B), matched by age, gender, and P-wave duration. The orientation of the terminal portion (positive or negative) of the Z-lead was assessed as representing right precordial leads potentials. After 6 months follow-up, Group A was divided into two groups according to recurrence: G-A1--at least one recurrence (21 patients), and G-A2--no recurrence (20 patients). Fragmented electrical activity (FEA) was observed in 19 patients of G-A1 and in 2 of G-A2 (odds ratio = 85.5; p<<0.001). STA showed 90.5% sensitivity and 90.0% specificity for early recurrence of AF. After 12 months, no patients of G-A2 and 15 of G-A1 developed >3 episodes of persistent AF, being FEA observed in 13 (odds ratio = 14.6, p = 0.002). No episodes of AF were observed in Group B. Average time for recurrence of FEA positive patients (4.3 +/- 0.7 months) was significantly shorter than of G-A2 (7.4+/-0.7 months), and log-rank analysis revealed significant difference of event-free rate over time (p = 0.004). In a logistic regression model FEA, use of amiodarone and a positive terminal portion of the Z-lead of the P-SAECG were independent predictors of recurrence of idiopathic and persistent AF.
authors.affiliation: Section of Cardiac Electrophysiology and Arrhythmia, Department of Cardiology, State University of Rio de Janeiro, Rio de Janeiro, Brazil. ecgar@uerj.br
authors.forename: Paulo Roberto
authors.initials: PR
authors.lastname: Benchimol Barbosa
authors.forename: Alfredo
authors.initials: A
authors.lastname: de Souza Bomfim
authors.forename: Eduardo Corrêa
authors.initials: EC
authors.lastname: Barbosa
authors.forename: Paulo
authors.initials: P
authors.lastname: Ginefra
authors.forename: Silvia
authors.initials: S
authors.lastname: Helena Cardoso Boghossian
authors.forename: Cleonilce
authors.initials: C
authors.lastname: Destro
authors.forename: Jurandir
authors.initials: J
authors.lastname: Nadal
mesh_terms: D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000175:diagnosis*; D016022:Case-Control Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D011237:Predictive Value of Tests; D012008:Recurrence; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D016019:Survival Analysis
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone