Anders Jönsson

Université Victor Segalen Bordeaux 2, Burdeos, Aquitaine, France

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Publications (11)49.45 Total impact

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    ABSTRACT: Catheter ablation of long-lasting persistent atrial fibrillation (AF) has been performed with varying results using a combination of different techniques. Whether arrhythmia termination during ablation is associated with an improved clinical outcome is controversial. In this prospective study, 153 consecutive patients (56 +/- 10 years) underwent catheter ablation of persistent AF (25 +/- 33 months) using a stepwise approach with the desired procedural endpoint being AF termination. Repeat ablation was performed for patients with recurrent AF or atrial tachycardia (AT) after a 1 month blanking period. A minimum follow-up of 12 months with repeated Holter monitoring was performed. Atrial fibrillation was terminated in 130 patients (85%). There was a lower incidence of AF in those patients in whom AF was terminated during the index procedure compared with those who had not (5 vs. 39% P < 0.0001, mean follow-up 32 +/- 11 months). Seventy-nine patients underwent repeat procedures: 64/130 in the termination group (6 AF, 58 AT) and 15 in the non-termination group (9 AF, 7 AT). After repeat ablation, sinus rhythm was maintained in 95% in whom AF was terminated compared with 52% in those in whom AF could not be terminated. Procedural termination of long-lasting AF by catheter ablation alone is associated with an improved outcome.
    European Heart Journal 03/2009; 30(9):1105-12. · 14.72 Impact Factor
  • Circulation 12/2006; 114(19):e569-70. · 14.95 Impact Factor
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    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.
    Journal of Cardiovascular Electrophysiology 11/2006; 17(s3):S28 - S36. · 3.48 Impact Factor
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    ABSTRACT: Left atrial (LA) linear lesions are effective in substrate modification for atrial fibrillation (AF). However, achievement of complete conduction block remains challenging and conduction recovery is commonly observed. The aim of the study was to investigate the localization of gap sites of recovered LA linear lesions. Forty-eight patients with paroxysmal (n = 26) and persistent/permanent (n = 22) AF underwent repeat ablation after pulmonary vein (PV) isolation and LA linear ablation at the LA roof and/or mitral isthmus due to recurrences of AF or flutter. In 35 patients, conduction through the mitral isthmus line (ML) had recovered whereas roof-line recovery was observed in 30 patients. The gaps within the ML were distributed to the junction between left inferior PV and left atrial appendage in 66%, the middle part of the ML in 20%, and in 8% to the endocardial aspect of the ML while only 6% of lines showed an epicardial site of recovery. The RL predominantly recovered close to the right superior PV (54%) and less frequently in the mid roof or close to the left PV (both 23%). Reablation of lines required significantly shorter RF durations (ML: 7.24 +/- 5.55 minutes vs 24.08 +/- 9.38 minutes, RL: 4.24 +/- 2.34 minutes vs 11.54 +/- 6.49 minutes; P = 0.0001). Patients with persistent/permanent AF demonstrated a significantly longer conduction delay circumventing the complete lines than patients with paroxysmal AF (228 +/- 77 ms vs 164 +/- 36 ms, P = 0.001). Gaps in recovered LA lines were predominantly located close to the PVs where catheter stability is often difficult to achieve. Shorter RF durations are required for reablation of recovered linear lesions. Conduction times around complete LA lines are significantly longer in patients with persistent/permanent AF as compared to patients with paroxysmal AF.
    Journal of Cardiovascular Electrophysiology 11/2006; 17(10):1106-11. · 3.48 Impact Factor
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    ABSTRACT: 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. 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. 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.
    Journal of Cardiovascular Electrophysiology 09/2006; 17(9):965-72. · 3.48 Impact Factor
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    ABSTRACT: 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. 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. 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.
    Journal of Cardiovascular Electrophysiology 09/2006; 17(8):807-12. · 2.88 Impact Factor
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    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.
    Journal of Interventional Cardiac Electrophysiology 08/2006; 16(3):153-167. · 1.55 Impact Factor
  • Heart Rhythm 07/2006; 3(6):748-50. · 4.92 Impact Factor
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    ABSTRACT: Much of our understanding of the mechanisms of macro re-entrant atrial tachycardia comes from study of cavotricuspid isthmus (CTI) dependent atrial flutter. In the majority of cases, the diagnosis can be made from simple analysis of the surface ECG. Endocardial mapping during tachycardia allows confirmation of the macro re-entrant circuit within the right atrium while, at the same time, permitting curative catheter ablation targeting the critical isthmus of tissue located between the tricuspid annulus and the inferior vena cava. The procedure is short, safe and by demonstration of an electrophysiological endpoint - bidirectional conduction block across the CTI - is associated with an excellent outcome following ablation. It is now fair to say that catheter ablation should be considered as a first line therapy for patients with documented CTI-dependent atrial flutter.
    Indian pacing and electrophysiology journal 02/2006; 6(2):100-10.
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    ABSTRACT: Much of our understanding of the mechanisms of macro re-entrant atrial tachycardia comes from study of cavotricuspid isthmus (CTI) dependent atrial flutter. In the majority of cases, the diagnosis can be made from simple analysis of the surface ECG. Endocardial mapping during tachycardia allows confirmation of the macro re-entrant circuit within the right atrium while, at the same time, permitting curative catheter ablation targeting the critical isthmus of tissue located between the tricuspid annulus and the inferior vena cava. The procedure is short, safe and by demonstration of an electrophysiological endpoint - bidirectional conduction block across the CTI - is associated with an excellent outcome following ablation. It is now fair to say that catheter ablation should be considered as a first line therapy for patients with documented CTI-dependent atrial flutter.
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    ABSTRACT: As in atrial fibrillation (AF), while both triggers and substrate may theoretically be the target of catheter ablation strategies, the presently published literature on catheter ablation of ventricular fibrillation (VF), including isolated case reports, has focused on targeting triggers.1–11The large mass of ventricular myocardium, the importance of maintaining normal mechanical ventricular function, and the risk of creating other forms of malignant arrhythmias mean that ablation strategies aimed at substrate modification are not suitable using the currently available technology. However, previous work in AF has shown that both triggers and substrate may share a close structural relationship. The pulmonary veins play an important role in the initiation and maintenance of AF,12 and recent studies have shed light on their role in the maintenance of AF in some patients. Similarly, several experimental studies demonstrated that Purkinje fibers act as initiators and perpetuators of VF.13,14 Hence, by ablating an area in which the triggering ectopics are found to originate, an additional effect might be substrate modification if the area is implicated in the maintenance of VF.