Dataset Information

Functional nature of electrogram fractionation demonstrated by left atrial high-density mapping.

ABSTRACT:

Background

Complex fractionated atrial electrograms (CFAE) are targets of atrial fibrillation (AF) ablation. Serial high-density maps were evaluated to understand the impact of activation direction and rate on electrogram (EGM) fractionation.

Methods and results

Eighteen patients (9 persistent) underwent high-density, 3-dimensional, left-atrial mapping (>400 points/map) during AF, sinus (SR), and CS-paced (CSp) rhythms. In SR and CSp, fractionation was defined as an EGM with ≥4 deflections, although, in AF, CFE-mean <80 ms was considered as continuous CFAE. The anatomic distribution of CFAE sites was assessed, quantified, and correlated between rhythms. Mechanisms underlying fractionation were investigated by analysis of voltage, activation, and propagation maps. A minority of continuous CFAE sites displayed EGM fractionation in SR (15+/-4%) and CSp (12+/-8%). EGM fractionation did not match between SR and CSp at 70+/-10% sites. Activation maps in SR and CSp showed that wave collision (71%) and regional slow conduction (24%) caused EGM fractionation. EGM voltage during AF (0.59+/-0.58 mV) was lower than during SR and CSp (>1.0 mV) at all sites. During AF, the EGM voltage was higher at continuous CFAE sites than at non-CFAE sites (0.53 mV (Q1, Q3: 0.33 to 0.83) versus 0.30 mV (Q1, Q3: 0.18 to 0.515), P<0.00001). Global LA voltage in AF was lower in patients with persistent AF versus patients with paroxysmal AF (0.6+/-0.59 mV versus 1.12+/-1.32 mV, P<0.01).

Conclusions

The distribution of fractionated EGMs is highly variable, depending on direction and rate of activation (SR versus CSp versus AF). Fractionation in SR and CSp rhythms mostly resulted from wave collision. All sites with continuous fractionation in AF displayed normal voltage in SR, suggesting absence of structural scar. Thus, many fractionated EGMs are functional in nature, and their sites dynamic.

SUBMITTER: Jadidi AS

PROVIDER: S-EPMC3423961 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature

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Publications

Functional nature of electrogram fractionation demonstrated by left atrial high-density mapping.

Jadidi Amir S AS Duncan Edward E Miyazaki Shinsuke S Lellouche Nicolas N Shah Ashok J AJ Forclaz Andrei A Nault Isabelle I Wright Matthew M Rivard Lena L Liu Xingpeng X Scherr Daniel D Wilton Stephen B SB Sacher Frédéric F Derval Nicolas N Knecht Sebastien S Kim Steven J SJ Hocini Mélèze M Narayan Sanjiv S Haïssaguerre Michel M Jaïs Pierre P

Circulation. Arrhythmia and electrophysiology 20120103 1

<h4>Background</h4>Complex fractionated atrial electrograms (CFAE) are targets of atrial fibrillation (AF) ablation. Serial high-density maps were evaluated to understand the impact of activation direction and rate on electrogram (EGM) fractionation.<h4>Methods and results</h4>Eighteen patients (9 persistent) underwent high-density, 3-dimensional, left-atrial mapping (>400 points/map) during AF, sinus (SR), and CS-paced (CSp) rhythms. In SR and CSp, fractionation was defined as an EGM with ≥4 de ...[more]

PMID: 22215849

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Project description:BackgroundLow-voltage-substrate (LVS)-guided ablation for persistent atrial fibrillation (AF) has been described either in sinus rhythm (SR) or AF. Prolonged fractionated potentials (PFPs) may represent arrhythmogenic slow conduction substrate and potentially co-localize with LVS. We assess the spatial correlation of PFP identified in AF (PFP-AF) to those mapped in SR (PFP-SR). We further report the relationship between LVS and PFPs when mapped in AF or SR.Materials and methodsThirty-eight patients with ablation naïve persistent AF underwent left atrial (LA) high-density mapping in AF and SR prior to catheter ablation. Areas presenting PFP-AF and PFP-SR were annotated during mapping on the LA geometry. Low-voltage areas (LVA) were quantified using a bipolar threshold of 0.5 mV during both AF and SR mapping. Concordance of fractionated potentials (CFP) (defined as the presence of PFPs in both rhythms within a radius of 6 mm) was quantified. Spatial distribution and correlation of PFP and CFP with LVA were assessed. The predictors for CFP were determined.ResultsPFPs displayed low voltages both during AF (median 0.30 mV (Q1-Q3: 0.20-0.50 mV) and SR (median 0.35 mV (Q1-Q3: 0.20-0.56 mV). The duration of PFP-SR was measured at 61 ms (Q1-Q3: 51-76 ms). During SR, most PFP-SRs (89.4 and 97.2%) were located within LVA (<0.5 mV and <1.0 mV, respectively). Areas presenting PFP occurred more frequently in AF than in SR (median: 9.5 vs. 8.0, p = 0.005). Both PFP-AF and PFP-SR were predominantly located at anterior LA (>40%), followed by posterior LA (>20%) and septal LA (>15%). The extent of LVA < 0.5 mV was more extensive in AF (median: 25.2% of LA surface, Q1-Q3:16.6-50.5%) than in SR (median: 12.3%, Q1-Q3: 4.7-29.4%, p = 0.001). CFP in both rhythms occurred in 80% of PFP-SR and 59% of PFP-AF (p = 0.008). Notably, CFP was positively correlated to the extent of LVA in SR (p = 0.004), but not with LVA in AF (p = 0.226). Additionally, the extent of LVA < 0.5 mV in SR was the only significant predictor for CFP, with an optimal threshold of 16% predicting high (>80%) fractionation concordance in AF and SR.ConclusionSubstrate mapping in SR vs. AF reveals smaller areas of low voltage and fewer sites with PFP. PFP-SR are located within low-voltage areas in SR. There is a high degree of spatial agreement (80%) between PFP-AF and PFP-SR in patients with moderate LVA in SR (>16% of LA surface). These findings should be considered when substrate-based ablation strategies are applied in patients with the left atrial low-voltage substrate with recurrent persistent AF.

Project description:BackgroundIt is unknown which features of unipolar atrial electrogram (U-AEGM) morphology are affected by ageing and whether age-related changes in U-AEGM morphology are equally distributed throughout the right and left atria.Patients and methodsEpicardial high-resolution mapping was performed in patients undergoing coronary artery bypass grafting surgery during sinus rhythm (SR). Mapping areas include the right atrium (RA), left atrium (LA), pulmonary vein area (PVA) and Bachmann's bundle (BB). Patients were categorized into a young (age < 60) and aged (age ≥ 60) group. U-AEGM were classified as single potentials (SPs, one deflection), short double potentials (SDPs, deflection interval ≤ 15ms), long double potentials (LDPs, deflection interval > 15ms) and fractionated potentials (FPs, ≥3 deflections).ResultsA total of 213 patients (age: 67 (59-73) years; young group N = 58, aged group N = 155) were included. Only at BB, the proportion of SPs (p = 0.007) was significantly higher in the young group, while the proportion of SDPs (p = 0.051), LDPs (p = 0.004) and FPs (p = 0.006) was higher in the aged group. After adjusting for potential confounders, older age was associated with a reduction in SPs [regression coefficient (β): -6.33, 95% confident interval (CI): -10.37 to -2.30] at the expense of an increased proportion of SDPs (β: 2.49, 95% CI: 0.09 to 4.89), LDPs (β: 1.94, 95% CI: 0.21 to 3.68) and FPs (β: 1.90, 95% CI: 0.62 to 3.18).ConclusionsAge-related remodeling particularly affects BB as indicated by the decreased amount of non-SP at this location in the elderly.Key MessagesAgeing preferentially affects the morphology of unipolar atrial electrograms recorded at Bachmann's bundle.At Bachmann's bundle, the proportion of short double-, long double- and fractionated potentials increase during ageing at the expense of a decrease in the proportion of single potentials, reflecting aggravation of abnormalities in conduction.The increase in abnormal unipolar atrial electrograms at Bachmann's bundle during ageing supports the concept that Bachmann's bundle may play an important role in development of age-related arrhythmias such as atrial fibrillation.

Project description:BackgroundCatheter ablation therapy involving isolation of pulmonary veins (PVs) from the left atrium is performed to terminate atrial fibrillation (AF). Unfortunately, standalone PV isolation procedure has shown to be a suboptimal success with AF continuation or recurrence. One reason, especially in patients with persistent or high-burden paroxysmal AF, is known to be due to the formation of repeating-pattern AF sources with a meandering core inside the atria. However, there is a need for accurate mapping and localization of these sources during catheter ablation.MethodsA novel AF source area probability (ASAP) mapping algorithm was developed and evaluated in 2D and 3D atrial simulated tissues with various arrhythmia scenarios and a retrospective study with three cases of clinical human AF. The ASAP mapping analyzes the electrograms collected from a multipole diagnostic catheter that is commonly used during catheter ablation procedure to intelligently sample the atria and delineate the trajectory path of a meandering repeating-pattern AF source. ASAP starts by placing the diagnostic catheter at an arbitrary location in the atria. It analyzes the recorded bipolar electrograms to build an ASAP map over the atrium anatomy and suggests an optimal location for the subsequent catheter location. ASAP then determines from the constructed ASAP map if an AF source has been delineated. If so, the catheter navigation is stopped and the algorithm provides the area of the AF source. Otherwise, the catheter is navigated to the suggested location, and the process is continued until an AF-source area is delineated.ResultsASAP delineated the AF source in over 95% of the simulated human AF cases within less than eight catheter placements regardless of the initial catheter placement. The success of ASAP in the clinical AF was confirmed by the ablation outcomes and the electrogram patterns at the delineated area.ConclusionOur analysis indicates the potential of the ASAP mapping to provide accurate information about the area of the meandering repeating-pattern AF sources as AF ablation targets for effective AF termination. Our algorithm could improve the success of AF catheter ablation therapy by locating and subsequently targeting patient-specific and repeating-pattern AF sources inside the atria.

Dataset Information

Functional nature of electrogram fractionation demonstrated by left atrial high-density mapping.

Background

Methods and results

Conclusions

Publications

Functional nature of electrogram fractionation demonstrated by left atrial high-density mapping.

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