| 1. |
- Haissaguerre, Michel, et al.
(författare)
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Localized sources maintaining atrial fibrillation organized by prior ablation
- 2006
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Ingår i: Circulation. - 0009-7322 .- 1524-4539. ; 113, s. 616-625
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Tidskriftsartikel (refereegranskat)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. |
- Haïssaguerre, Michel, et al.
(författare)
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Sudden cardiac arrest associated with early repolarization
- 2008
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 358:19, s. 2016-2023
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Early repolarization is a common electrocardiographic finding that is generally considered to be benign. Its potential to cause cardiac arrhythmias has been hypothesized from experimental studies, but it is not known whether there is a clinical association with sudden cardiac arrest.METHODS: We reviewed data from 206 case subjects at 22 centers who were resuscitated after cardiac arrest due to idiopathic ventricular fibrillation and assessed the prevalence of electrocardiographic early repolarization. The latter was defined as an elevation of the QRS-ST junction of at least 0.1 mV from baseline in the inferior or lateral lead, manifested as QRS slurring or notching. The control group comprised 412 subjects without heart disease who were matched for age, sex, race, and level of physical activity. Follow-up data that included the results of monitoring with an implantable defibrillator were obtained for all case subjects.RESULTS: Early repolarization was more frequent in case subjects with idiopathic ventricular fibrillation than in control subjects (31% vs. 5%, P<0.001). Among case subjects, those with early repolarization were more likely to be male and to have a history of syncope or sudden cardiac arrest during sleep than those without early repolarization. In eight subjects, the origin of ectopy that initiated ventricular arrhythmias was mapped to sites concordant with the localization of repolarization abnormalities. During a mean (+/-SD) follow-up of 61+/-50 months, defibrillator monitoring showed a higher incidence of recurrent ventricular fibrillation in case subjects with a repolarization abnormality than in those without such an abnormality (hazard ratio, 2.1; 95% confidence interval, 1.2 to 3.5; P=0.008).CONCLUSIONS: Among patients with a history of idiopathic ventricular fibrillation, there is an increased prevalence of early repolarization.
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| 3. |
- Jais, Pierre, et al.
(författare)
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Stepwise catheter ablation of chronic atrial fibrillation : Importance of descrete anatomic sites for termination
- 2006
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Ingår i: Journal of Cardiovascular Electrophysiology. - : Wiley. - 1540-8167 .- 1045-3873. ; 17:Suppl 3, s. 28-36
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chronic atrial fibrillation (CAF) can be acutely terminated using a combination of approaches targeting thoracic veins, left atrial areas showing rapid/heterogeneous electrical activity, and by linear ablation. This observational study emphasizes the crucial role for conventional endocardial mapping to identify discrete anatomical sites, ablation of which is indispensable for the achievement of atrial fibrillation (AF) termination. Methods: Eighty consecutive patients with CAF underwent catheter ablation using the stepwise approach. Pulmonary vein isolation and roof-line ablation were performed as the initial two steps in all patients. In the presence of locally rapid or heterogeneous activity, ablation was then performed at all sites within the left atrium and coronary sinus (CS) region with the endpoint of local organization or slowing. If AF persisted, the mitral isthmus was targeted. Patients in whom AF terminated during one of these five ablation steps were differentiated from those in whom AF was terminated by radiofrequency ablation at a single discrete anatomic site within 1 minute. Electrograms at discrete anatomic sites of termination were classified according to morphology. Results: Termination of AF was achieved in 69 (86%) patients by ablation alone. In 50 patients (72%), this occurred while following the predetermined ablation schema. In the remaining 19 patients (28%), ablation targeting a discrete site (preferentially located at the CS, the base of left atrial appendage, and the interatrial septum) terminated AF. Such sites were identified by (1) continuous electrical activity and fractionation and (2) bursts of short cycle activity (130–160 msec), centrifugal activation or local activation gradients, indicating sources perpetuating AF. Conclusion: In 28% of patients with termination of CAF, the final successful ablation site is anatomically discrete and displays electrophysiological characteristics that can be effectively identified by point and activation mapping. Failure to identify these sites may significantly reduce the likelihood of termination of CAF by catheter ablation.
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| 4. |
- Nault, Isabelle, et al.
(författare)
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Clinical value of fibrillatory wave amplitude on surface ECG in patients with persistent atrial fibrillation
- 2009
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Ingår i: Journal of Interventional Cardiac Electrophysiology. - : Springer Science and Business Media LLC. - 1572-8595 .- 1383-875X. ; 26:1, s. 11-19
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Tidskriftsartikel (refereegranskat)abstract
- We postulated that amplitude of fibrillatory (F)-wave in patients with persistent AF would correlate with clinical characteristics and outcome in patients undergoing catheter ablation for AF. Maximal and mean amplitude of F-waves were measured in V1 and lead II in 90 patients prior to ablation for persistent AF. F-wave amplitudes were correlated to clinical, echocardiographic variables, and outcome. F-wave a parts per thousand yenaEuro parts per thousand 0.1 mV in lead II and V1was correlated with younger age and shorter AF history, and in lead II only was correlated with a smaller left atrium. Higher F-wave amplitude at baseline predicted AF termination during ablation. Maximal amplitude of a parts per thousand yenaEuro parts per thousand 0.07 mV predicted AF termination by ablation with 82%/79% sensitivity and 68%/73% specificity in V1/lead II respectively. An association between F-wave amplitude and AF recurrence was observed. Forty-three percent of patients with mean f wave amplitude < 0.05 in lead V1 had AF recurrence compared to 12% of those with F-wave a parts per thousand yenaEuro parts per thousand 0.05 (p = 0.004). Longer AF duration, older age and larger LA size are associated with fine AF amplitude. High F-wave amplitude predicts procedural termination of arrhyhmia in patients with persistent AF and freedom from AF upon follow-up.
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| 5. |
- ONeill, Mark D, et al.
(författare)
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The stepwise ablation approach for chronic atrial fibrillation - evidence for a cumulative effect
- 2006
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Ingår i: Journal of Interventional Cardiac Electrophysiology. - : Springer Science and Business Media LLC. - 1383-875X .- 1572-8595. ; 16, s. 153-167
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Tidskriftsartikel (refereegranskat)abstract
- Treatment options for atrial fibrillation (AF) have evolved from simple, fluoroscopy-guided pulmonary vein isolation for those patients with paroxysmal AF to complex, multi-modality procedures targeting not only anatomic structures but also electrophysiologic phenomena including complex fractionated electrograms, sites of dominant frequency and local non-venous drivers in patients with persistent and permanent AF. The stepwise ablation approach is a novel technique whereby structures contributing to initiation and maintenance of AF are sequentially targeted by radiofrequency ablation. Broadly divided into pulmonary veins, left atrial (LA) roof, left atrium (incorporating all anatomic regions of the chamber), mitral isthmus and non-LA structures, each region is targeted in sequence and the impact of ablation upon the global fibrillatory process assessed by measurement of AF cycle length (AFCL) at a site remote from the ablation target. In addition to pulmonary vein electrical disconnection and demonstrable complete conduction block across the roof and mitral isthmus lines (when performed), ablation is performed at those sites displaying continuous electrical and complex fractionated activity, with the endpoint of local organization, as well as at sites displaying electrograms consistent with focal sources driving AF. Ablation is accompanied by a cumulative increase in the AFCL prior to termination of AF by conversion either directly to sinus rhythm or to an atrial tachycardia which is then mapped conventionally and ablated. There is a ceiling of ablation within the LA beyond which further ablation is unlikely to result in a clinical benefit and should prompt evaluation of the contribution of the right atrium to maintenance of AF. The stepwise approach benefits from the integration of anatomic and electrophysiologic information to achieve a high level of success in termination of chronic AF by catheter ablation.
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| 6. |
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| 7. |
- Rostock, Thomas, et al.
(författare)
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Fibrillating areas isolated within the left atrium after radiofrequency linear catheter ablation
- 2006
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Ingår i: Cardiovascular Electrophysiology. - : Wiley. - 1045-3873 .- 1540-8167. ; 17, s. 807-812
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Tidskriftsartikel (refereegranskat)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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| 8. |
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| 9. |
- Takahashi, Yoshihide, et al.
(författare)
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Sites of focal atrial activity characterized by endocardial mapping during atrial fibrillation
- 2006
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Ingår i: Journal of the American College of Cardiology. - : Elsevier. - 0735-1097 .- 1558-3597. ; 47:10, s. 2005-2012
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesThe aim of the present study was to assess the feasibility of identifying sites of focal atrial activity by localized high-density endocardial mapping during atrial fibrillation (AF).BackgroundSites of focal activity in the left atrium have been demonstrated by epicardial mapping during AF.MethodsTwenty-four patients (15 with paroxysmal, 3 with persistent, and 6 with permanent AF) underwent endocardial mapping during AF. A 20-pole catheter with five radiating spines was used to map both atria for 30 s in each of 10 pre-determined segments. A focal activity was defined as ≥3 atrial cycles with activation spreading from center to periphery of the mapping catheter. Catheter ablation was performed independent of the mapping results.ResultsSpontaneous focal activities were observed in 13 sites in the left atrium (9%; anterior 1, roof 2, posterior 6, inferior 4) in 12 patients (9 paroxysmal, 3 persistent). Focal activity was observed continuously (two sites) or intermittently (11 sites, median 5 episodes), and associated with shortening of the cycle length (from 183 ± 33 ms to 172 ± 29 ms; p < 0.05). The mean duration of an intermittent episode was 1.5 s (range 0.4 to 7.1 s). Atrial fibrillation terminated without ablation at the foci in all of 12 patients, but in 2 of them, re-initiated arrhythmia was successfully ablated at these foci. Nine of these 12 patients (75%) were arrhythmia-free without antiarrhythmic drugs during a follow-up period of 7.0 ± 3.1 months.ConclusionsTermination of AF without ablation at the sites of atrial focal activity suggests that this activity may be triggered by impulses originating from other regions, such as the pulmonary veins.
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