Functional Characterization of Atrial Electrograms in Sinus Rhythm Delineates Sites of Parasympathetic Innervation in Patients With Paroxysmal Atrial Fibrillation

University of California, Los Angeles, Los Ángeles, California, United States
Journal of the American College of Cardiology (Impact Factor: 16.5). 11/2007; 50(14):1324-31. DOI: 10.1016/j.jacc.2007.03.069
Source: PubMed


This study sought to characterize left atrial (LA) sinus rhythm electrogram (EGM) patterns and their relationship to parasympathetic responses during atrial fibrillation (AF) ablation.
The mechanistic basis of fractionated LA EGMs in patients with paroxysmal AF is not well understood.
We analyzed 1,662 LA ablation sites from 30 patients who underwent catheter ablation for paroxysmal AF. Pre-ablation EGM characteristics (number of deflections, amplitude, and duration) were measured in sinus rhythm. Parasympathetic responses during radiofrequency application (increase of atrial-His interval by > or =10 ms or decrease of sinus rate by > or =20%) were assessed at all sites. We also prospectively studied the effect of adenosine, a pharmacological agent mimicking acetylcholine signaling in myocytes, on LA EGMs. Finally, we performed mathematical simulations of atrial tissue to delineate possible mechanisms of fractionated EGMs in sinus rhythm.
A specific pattern of pre-ablation sinus rhythm EGM (deflections > or =4, amplitude > or =0.7 mV, and duration > or =40 ms) was strongly associated with parasympathetic responses (sensitivity 72%, specificity 91%). The sites associated with these responses were found to be located mainly in the posterior wall of the LA. Adenosine administration and mathematical simulation of the effect of acetylcholine were able to reproduce a similar EGM pattern.
Parasympathetic activation during AF ablation is associated with the presence of pre-ablation high-amplitude fractionated EGMs in sinus rhythm. Local acetylcholine release could potentially explain this phenomenon.

Download full-text


Available from: Alan Garfinkel
  • Source
    • "Kneller et al. [12] and Nattel et al. [13] analyzed AF maintenance through the action potential (AP) and effective refractory period (ERP) values induced by acetylcholine (ACh), using a patch clamp and computer model. Shivkumar et al. [14] concluded that parasympathetic activation during AF ablation is associated with the presence of a preablation high-amplitude fractionated EG in sinus rhythm via a waveform identification method. In our study, we aim to analyze the atrial vulnerability through the sinus EG of a canine AF model. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Atrial fibrillation (AF) can result in life-threatening arrhythmia, and a clinically convenient means for detecting vulnerability remains elusive. We investigated atrial vulnerability by analyzing the sinus electrogram (EG) from AF animal models using a phase synchronization method. Using acetylcholine (ACh)-induced acute canine AF models (n= 4), a total of 128 electrical leads were attached to the surface of the anterior and posterior atria, and the pulmonary veins to form an electrocardiological mapping system. ACh was injected at varying concentrations with ladder-type adjustments. Sinus EGs and induced AF EGs that pertain to specific ACh concentrations were recorded.We hypothesize that the atrial vulnerability may be correlated with the Shannon entropy (SE) of the phase difference matrix that is extracted from the sinus EG. Our research suggests that the combination of SE with the synchronization method enables the sinus node EG to be analyzed and used to estimate atrial vulnerability.
    Full-text · Article · Aug 2012 · IEEE transactions on bio-medical engineering
  • Source
    • "Common chaotic features like Correlation Dimension, Largest Lyapunov Exponent and Spatial Feeling Index were used in this paper. Literature shows that these features have significantly different for healthy vs. arrhythmic heart, men vs. women and night vs. day [2] [3] [4] [5] [6] [7] [8] [9]. EGM signals provide interesting information about electrical activity of internal regions of heart. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this research is to find relations between chaotic features of the Intracardiac Electrogram signal and the surface ECG based on Partial Least Square (PLS) Regression. Intracardiac Atrial Fibrillation database from Physionet (IAFDB) is selected database for this paper, and Correlation dimension (CD), Largest Lyapunov Exponent (LLE) and Spatial Feeling Index (SFI) are considered features. Coefficients of a linear formula between the chaotic features of ECG and Electrogram were computed for each region (bipolar electrodes) by PLS Regression method. Formulas acquired for estimating CD of Electrogram using those of surface ECG in AF patients was efficient, while efforts to obtain relations for LLF and SFI did not yield significant results. Moreover, it led to an important observation that the closer bipolar electrodes were to the heart apex, the greater coefficients of lead II would be. Results of this study propose a way to eliminate the risk of invasive procedure of Electrogram recording, reduce psychological stress of patients and reduce the cost.
    Full-text · Conference Paper · Oct 2010
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Resumen La ablación de fibrilación auricular puede resultar pro-arrítmica. Las taquicardias auriculares por macro-reentrada han sido reportadas hasta en 1/3 de los pacientes que son sometidos a ablación de fibrilación auricular. Métodos y Resultados: En el presente trabajo se utilizo un abordaje electrofisiológico para eliminar potenciales auriculares izquierdos fraccionados durante ritmo sinusal, sin la intención de crear líneas de bloqueo. Trescientos pacientes consecutivos con fibrilación auricular (paroxística n=218; persistente n=82) fueron incluidos. Luego del aislamiento eléctrico de las venas pulmonares, los potenciales auriculares fraccionados identificados como blancos de ablación en la aurícula izquierda fueron de mayor duración y menor voltaje que los electrogramas del tejido auricular adyacente (97.2±23.4 vs 42.1±17.3 ms; y 0.83 ± 0.7 mV vs 2.75±1.3 mV, p
    Full-text · Article · Sep 2009
Show more