| 1. |
- Haissaguerre, Michel, et al.
(author)
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Localized sources maintaining atrial fibrillation organized by prior ablation
- 2006
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In: Circulation. - 0009-7322 .- 1524-4539. ; 113, s. 616-625
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Journal article (peer-reviewed)abstract
- Background— Endocardial mapping of localized sources drivingatrial fibrillation (AF) in humans has not been reported.Methods and Results— Fifty patients with AF organizedby prior pulmonary vein and linear ablation were studied. AFwas considered organized if mapping during AF showed irregularbut discrete atrial complexes exhibiting consistent activationsequences for >75% of the time using a 20-pole catheter with5 radiating spines covering 3.5-cm diameter or sequential conventionalmapping. A site or region centrifugally activating the remainingatrial tissue defined a source. During AF with a cycle lengthof 211±32 ms, activation mapping identified 1 to 3 sourcesat the origin of atrial wavefronts in 38 patients (76%) predominantlyin the left atrium, including the coronary sinus region. Electrogramsat the earliest area varied from discrete centrifugal activationto an activity spanning 75% to 100% of the cycle length in 42%of cases, the latter indicating complex local conduction ora reentrant circuit. A gradient of cycle length (>20 ms)to the surrounding atrium was observed in 28%. Local radiofrequencyablation prolonged AF cycle length by 28±22 ms and eitherterminated AF or changed activation sequence to another organizedrhythm. In 4 patients, the driving source was isolated, surroundedby the atrium in sinus rhythm, and still firing at high frequency(228±31 ms) either permanently or in bursts.Conclusions— AF associated with consistent atrial activationsequences after prior ablation emanates mostly from localizedsources that can be mapped and ablated. Some sources harborelectrograms suggesting the presence of localized reentry.
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| 2. |
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| 3. |
- Rostock, Thomas, et al.
(author)
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Fibrillating areas isolated within the left atrium after radiofrequency linear catheter ablation
- 2006
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In: Cardiovascular Electrophysiology. - : Wiley. - 1045-3873 .- 1540-8167. ; 17, s. 807-812
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Journal article (peer-reviewed)abstract
- INTRODUCTION: Nonpulmonary vein sources have been implicated as potential drivers of atrial fibrillation (AF). This observational study describes regions of fibrillating atrial tissue isolated inadvertently from the left atrium (LA) following linear catheter ablation for AF. METHODS AND RESULTS: We report four patients with persistent/permanent AF who underwent pulmonary vein isolation with additional linear lesions and who presented with recurrent AF (mean AF cycle length [AFCL] 175-270 ms). Further catheter ablation resulted in the inadvertent electrical isolation of significant areas of the LA in which AF persisted at the same AFCL as was measured prior to disconnection, despite the restoration of sinus rhythm (SR) in all other left and right atrial areas, strongly suggesting that these islands were driving the remaining atria into fibrillation. The disconnected areas were located in the lateral LA, including the left atrial appendage (LAA) in three patients (limited to the LAA in one) and in the posterior LA in one patient. These isolated fibrillating regions represented 15-24% of the global LA surface, as estimated by electroanatomic mapping. CONCLUSION: Fibrillation can be maintained within electrically isolated regions of the LA following catheter ablation of AF, demonstrating the importance of atrial drivers in the maintenance of AF. Further mapping of these drivers is needed to characterize their mechanism and thereby allow for a more specific ablation strategy.
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| 4. |
- Sanders, Prashanthan, et al.
(author)
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Frequency mapping of the pulmonary veins in paroxysmal versus permanent atrial fibrillation
- 2006
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In: Journal of Cardiovascular Electrophysiology. - : Wiley. - 1540-8167 .- 1045-3873. ; 17, s. 965-972
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Journal article (peer-reviewed)abstract
- INTRODUCTION: The pulmonary veins (PVs) are a dominant source of triggers initiating atrial fibrillation (AF). While recent evidence implicates these structures in the maintenance of paroxysmal AF, their role in permanent AF is not known. The current study aims to compare the contribution of PV activity to the maintenance of paroxysmal and permanent AF. METHODS AND RESULTS: Thirty-four patients with paroxysmal AF (n = 20) or permanent AF (n = 14) undergoing ablation were studied. Prior to ablation, 32 seconds of electrograms were acquired from each PV and the coronary sinus (CS). The frequency of activity of each PV and CS was defined as the highest amplitude frequency on spectral analysis. The effects of ablation on the AF cycle length (AFCL) and frequency and on AF termination were determined. Significant differences were observed between paroxysmal and permanent AF. Paroxysmal AF demonstrates higher frequency PV activity (11.0 +/- 3.1 vs 8.8 +/- 3.0 Hz; P = 0.0003) but lower CS frequency (5.8 +/- 1.2 vs 6.9 +/- 1.4 Hz; P = 0.01) and longer AFCL (182 +/- 17 vs 158 +/- 21 msec; P = 0.002), resulting in greater PV to atrial frequency gradient (7.2 +/- 2.2 vs 4.2 +/- 2.9 Hz; P = 0.006). PV isolation in paroxysmal AF resulted in a greater decrease in atrial frequency (1.0 +/- 0.7 vs -0.05 +/- 0.4 Hz; P < 0.0001), greater prolongation of the AFCL (49 +/- 35 vs 5 +/- 6 msec; P < 0.0001), and more frequent AF termination (11/20 vs 0/14; P = 0.0007) compared to permanent AF. CONCLUSION: Paroxysmal AF is associated with higher frequency PV activity and lesser CS frequency compared to permanent AF. Isolation of the PVs had a greater impact on the fibrillatory process in paroxysmal AF compared to permanent AF, suggesting that while the PVs have a role in maintaining paroxysmal AF, these structures independently contribute less to the maintenance of permanent AF
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