Pulmonary Vein Conduction Research Articles

Effects of Chronic Fish Oil Supplementation on the Burden of Paroxysmal Atrial Tachyarrhythmias in Elderly Patients with Dual Chambered Pacemakers

Background: Epidemiological studies suggest that fish intake may reduce the incidence of atrial fibrillation (AF) in the elderly. The aim of this study was to examine the effect of chronic fish oil supplementation on the burden of paroxysmal atrial tachyarrhythmia or fibrillation (AT/AF) in the elderly. Methods: Thirty-five patients with at least two documented mode switches AT/AF were enrolled. AT/AF burden was documented in the first six months (observation period) followed by 6 g/day of fish oil supplementation for the next six months (active treatment) and then observation off fish oil for the last six months (off treatment). No changes in the device programming or pharmacological therapy were allowed in the interim. Preliminary results are presented. Results: Mean age of the fish oil group was 77± 6 yrs (56% females); 72%were on anti-arrhythmic drugs including amiodarone 22%, sotalol 33% and flecainide 17%; remains unknown. The aim of this study was to investigate the effects of chronic fish oil supplementation on pulmonary vein (PV) and left atrial (LA) electrophysiology in PAF. Methods:PatientswithPAFundergoingpulmonaryvein isolation were randomised ≥1 month prior to their procedure into a control group (n= 18) or a fish oil group (n= 18). The latter were supplemented with 6g/day of fish oil for a mean 40± 12 days. PV and LA effective refractory periods (ERPs), PV conduction and susceptibility to PV initiated AF were assessed. Results: Compared to the control group, the fish oil group had: (i) longer left (P= .002) and right sided PVERPs (P= .001); (ii) less PV ERP heterogeneity (left PVs, P= .001, right PVs, P= .07); (ii) longer left atrial ERPs (P= .02); (iii) no difference in PV conduction; (iv) lower incidence of PV induced AF during ERP testing (77% vs. 31%, P= .02) and to subsequent repeated paroxysms of AF (6.7% vs. 52.9%, P= .003); (v) prolongationofmeanAFcycle length (P= .009) and shortest AF cycle length in the PVs (P= .04). Conclusion: PAF patients chronically supplemented with fish oils exhibit distinctive electrophysiological properties including prolonged PV and left atrial ERPs and reduced susceptibility to the initiation and repeated paroxysms of AF. These changes may, in part, explain the anti-fibrillatory effect of chronic n− 3 PUFA supplementation in PAF.

Dormant pulmonary vein conduction induced by adenosine in patients with atrial fibrillation who underwent catheter ablation

intravenous administration of adenosine triphosphate (ATP) is used to induce transient pulmonary vein (PV) reconduction (dormant PV conduction) following PV isolation. This study investigated the detailed characteristics of dormant PV conduction in patients with atrial fibrillation (AF) who underwent catheter ablation. two hundred sixty consecutive patients (235 men; mean age, 54 ± 10 years) who underwent catheter ablation of their AF were included in this study. ATP was injected following PV isolation to induce dormant PV conduction, which was then eliminated by radiofrequency application. dormant PV conduction was induced by ATP in 60.4% (157/260) of the patients and in 25.3% (258/1,021) of the isolated PVs. This transient PV reconduction was more frequently observed in the left superior PV in comparison with other PVs (P < .0001). There was no significant difference in the prevalence of the dormant PV conduction among patients with paroxysmal AF, persistent AF, and long-lasting AF (62%, 66%, and 48%, respectively; P = .13). During the follow-up period, repeat AF ablation was performed in 70 patients with recurrent AF. The dormant PV conduction was less frequently induced in the repeat procedure than in the initial procedure (60.4% vs 31.4%, P < .0001). dormant PV conduction was evenly induced among AF types. The repeat PV isolation led to the decrease in incidence of the ATP-induced acute transient pharmacological PV reconduction.

Visualization of lesion transmurality and depth of necrosis using an ablation catheter that incorporates ultrasound imaging: A small step or a major leap forward on the road to a more durable catheter ablation procedure for treatment of atrial fibrillation?

Percutaneous catheter ablation has revolutionized the care of patients with atrial fibrillation. Pulmonary vein isolation has become the cornerstone of most ablation procedures for the treatment of atrial fibrillation following the observation by Haissaguerre et al 1 Haissaguerre M. Jais P. Shah D.C. et al. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med. 1998; 339: 659-666 Google Scholar that pulmonary veins were a frequent source of ectopic beats initiating atrial fibrillation. Pulmonary vein isolation may be combined with linear ablation or ablation of other targets for treatment of persistent or longstanding persistent atrial fibrillation. Pulmonary vein electrical reconnection to the left atrium is not uncommon and may be the primary reason for procedure failure among patients with paroxysmal atrial fibrillation. 2 Callans D.J. Gerstenfeld E.P. Dixit S. et al. Efficacy of repeat pulmonary vein isolation procedures in patients with recurrent atrial fibrillation. J Cardiovasc Electrophysiol. 2004; 15: 1050-1055 Google Scholar , 3 Shah A.N. Mittal S. Sichrovsky T.C. et al. Long-term outcome following successful pulmonary vein isolation: pattern and prediction of very late recurrence. J Cardiovasc Electrophysiol. 2008; 19: 661-667 Google Scholar , 4 Cheema A. Dong J. Dalal D. et al. Incidence and time course of early recovery of pulmonary vein conduction after catheter ablation of atrial fibrillation. J Cardiovasc Electrophysiol. 2007; 18: 387-391 Google Scholar Pulmonary vein reconnections also have been demonstrated to be important triggers in patients with persistent atrial fibrillation undergoing repeat ablation. 5 Haissaguerre M. Jais P. Shah D.C. et al. Catheter ablation of chronic atrial fibrillation targeting the reinitiating triggers. J Cardiovasc Electrophysiol. 2000; 11: 2-10 Google Scholar Recovery of conduction across linear ablation lesions is also likely to play a role in procedure failure among patients with persistent atrial fibrillation. 6 Rostock T. O'Neill M.D. Sanders P. et al. Characterization of conduction recovery across left atrial linear lesions in patients with paroxysmal and persistent atrial fibrillation. J Cardiovasc Electrophysiol. 2006; 17: 1106-1111 Google Scholar With current technology, some tissue that is ablated recovers electrical activity. Any technology that could safely increase the probability that ablated tissue would remain ablated would be an important contribution. Real-time lesion assessment using a novel combined ultrasound and radiofrequency ablation catheterHeart RhythmVol. 8Issue 2PreviewAssessment of lesion size and transmurality is currently via indirect measures. Real-time image assessment may allow ablation parameters to be titrated to achieve transmurality and reduce recurrences due to incomplete lesions. Full-Text PDF

General anesthesia reduces the prevalence of pulmonary vein reconnection during repeat ablation when compared with conscious sedation: Results from a randomized study

Radiofrequency catheter ablation of atrial fibrillation can be performed under general anesthesia or conscious sedation at the physician's preference. We randomized a series of consecutive patients with paroxysmal atrial fibrillation (AF) undergoing radiofrequency catheter ablation to either general anesthesia or conscious sedation to assess differences in pulmonary vein (PV) reconnection during redo procedures and impact on success rate. A total of 257 consecutive patients with paroxysmal AF undergoing AF ablation were enrolled and randomized to either conscious sedation with fentanyl or midazolam (128 patients, group 1) and general anesthesia (129 patients, group 2). In all patients, a high dosage of isoproterenol up to 30 μg/min was used to disclose PV reconnection or extra PV firings. Baseline clinical characteristics were not significantly different between the 2 groups. At 17 ± 8 month follow-up after the first ablation, 88 (69%) patients in group 1 were free of atrial arrhythmias off all antiarrhythmic drugs (AAD), as compared with 114 (88%) in group 2 (log-rank P <.001). All patients with recurrence had a second procedure. At the repeat procedure, 42% (66 of 158) of PVs in group 1 had recovered PV conduction, compared with 19% (11 of 57) in group 2 (P = .003). Compared with group 1, group 2 had a significantly shorter fluoroscopy time (53 ± 9 min vs. 84 ± 21 min, P <.001) and procedure time (2.4 ± 1.4 h vs. 3.6 ± 1.1 h, P <.001). The use of general anesthesia is associated with higher cure rate with a single procedure, and it seems to reduce the prevalence of PV reconnection observed at the time of repeat ablation.

Long-Term Clinical Implication of the Occurrence of Dissociated Pulmonary Vein Activities After Circumferential Left Atrial Ablation in Patients With Paroxysmal Atrial Fibrillation

The incidence and clinical implication of dissociated pulmonary vein (PV) electrical activities after circumferential antrum PV ablation for paroxysmal atrial fibrillation (AF) remains unclear. A total of 196 patients with symptomatic paroxysmal AF who underwent circumferential antrum PV ablation were prospectively studied. Dissociated PV electrical activities were observed in 101 patients (Group 1), but absent in the remaining 95 patients (Group 2). There were no significant differences in the baseline clinical characteristics between them, except that Group 2 had a higher prevalence of hypertension (30 vs. 44%, P = 0.04). After 21.8 ± 7.9 months of follow-up, 148 had no recurrence of AF after the initial procedure. AF recurrence rate was significantly higher in Group 2 than in Group 1 (P = 0.023). Relapse of PV conduction was the major cause of AF recurrence in both groups (16/16 vs. 19/23, P = 0.08), and the overall procedural success rate after the redo ablation procedure was similar in the 2 groups (90 vs. 86%, P = 0.44). However, the total number of patients with non-PV foci was significantly higher in Group 2 than in Group 1 (12/95 vs. 2/101, P < 0.01). Dissociated PV electrical activities might identify a subgroup of patients with relatively higher initial procedural success with circumferential PV antrum ablation.

E0562 Impact of circumferential pulmonary vein isolation on electrophysiologic properties of pulmonary veins in patients with paroxysmal atrial fibrillation

ObjectiveThe special electrophysiological characteristics of pulmonary veins (PVs) are highly correlated with the incidence of Atrial fibrillation (AF), and circumferential PV isolation (CPVI) has been demonstrated to be effective in...

Comparison of the clinical outcome after pulmonary vein isolation based on the appearance of adenosine-induced dormant pulmonary vein conduction

The elimination of transient pulmonary vein (PV) reconduction (dormant PV conduction) revealed by adenosine in addition to PV isolation reduced the atrial fibrillation (AF) recurrence after catheter ablation. The dormant PV conduction is induced in approximately half of the AF patients that undergo PV isolation. The present study compared the clinical outcome of AF ablation in patients whose dormant PV conduction was eliminated by additional radiofrequency applications with the outcome in patients without dormant conduction. A total of 233 consecutive patients (206 male, 54.2 +/- 10.1 years) that underwent AF ablation were included in the present study. Dormant PV conduction was induced by the administration of adenosine triphosphate after PV isolation and was eliminated by supplemental radiofrequency application. All patients were followed up for >12 months (mean 903 days) after the first ablation. Following PV isolation, dormant PV conduction was induced in 139 (59.7%) of 233 patients and was successfully eliminated in 98% (223/228) of those in the first ablation procedure. After the first procedure, 63.9% (149/233) of patients were free from AF recurrence events. The success rates of a single or final AF ablation in patients with the appearance of the dormant PV conduction were similar to those of patients without dormant conduction (P = .69 and P = .69, respectively). Dormant PV conduction was induced in over half of the patients with AF. After the elimination of adenosine triphosphate-induced reconnection, the clinical outcome of patients with the dormant PV conduction was equivalent to that of patients without conduction.

Mechanisms by Which Adenosine Restores Conduction in Dormant Canine Pulmonary Veins

Adenosine acutely reconnects pulmonary veins (PVs) after radiofrequency application, revealing "dormant conduction" and identifying PVs at risk of reconnection, but the underlying mechanisms are unknown. Canine PV and left-atrial (LA) action potentials were recorded with standard microelectrodes and ionic currents with whole-cell patch clamp before and after adenosine perfusion. PVs were isolated with radiofrequency current application in coronary-perfused LA-PV preparations. Adenosine abbreviated action potential duration similarly in PV and LA but significantly hyperpolarized resting potential (by 3.9+/-0.5%; P<0.05) and increased dV/dt(max) (by 34+/-10%) only in PV. Increased dV/dt(max) was not due to direct effects on I(Na), which was reduced similarly by adenosine in LA and PV but correlated with resting-potential hyperpolarization (r=0.80). Adenosine induced larger inward rectifier K(+)current (I(KAdo)) in PV (eg, -2.28+/-0.04 pA/pF; -100 mV) versus LA (-1.28+/-0.16 pA/pF). Radiofrequency ablation isolated PVs by depolarizing resting potential to voltages positive to -60 mV. Adenosine restored conduction in 5 dormant PVs, which had significantly more negative resting potentials (-57+/-6 mV) versus nondormant (-46+/-5 mV, n=6; P<0.001) before adenosine. Adenosine hyperpolarized both, but more negative resting-potential values after adenosine in dormant PVs (-66+/-6 mV versus -56+/-6 mV in nondormant; P<0.001) were sufficient to restore excitability. Adenosine effects on resting potential and conduction reversed on washout. Spontaneous recovery of conduction occurring in dormant PVs after 30 to 60 minutes was predicted by the adenosine response. Adenosine selectively hyperpolarizes canine PVs by increasing I(KAdo). PVs with dormant conduction show less radiofrequency-induced depolarization than nondormant veins, allowing adenosine-induced hyperpolarization to restore excitability by removing voltage-dependent I(Na) inactivation and explaining the restoration of conduction in dormant PVs.

Electroanatomic Properties of the Pulmonary Veins in AF Patients: Slowed Conduction and Low Voltage as a Marker of Arrhythmogenicity

Introduction: Rapid pulmonary vein (PV) activity is a critical factor in the mechanism of atrial fibrillation (AF). There are only limited reports of the nature of PV electrophysiology which facilitates this activity. Methods: Twenty-four pts undergoing RFA for AF and 11 control pts having RF for left sided SVT were studied. Detailed high density maps of the PVs were created using 3D electroanatomic mapping. PV conduction, voltage, length of recorded signals (sleeve length) andERPat 2 cycle lengths were measured. Complex fractionated electrograms (CFE, CL< 120ms) were assessed in patients in spontaneous AF using an automated algorithm.

Dormant pulmonary vein conduction unmasked by external electrical cardioversion

A 52-year-old man suffering from drug-refractory paroxysmal atrial fibrillation (AF) was referred to our institution for pulmonary vein isolation (PVI). Electrical PVI using an irrigated-tip radiofrequency ablation catheter guided by a circular mapping catheter was performed during sustained AF.

Circumferential pulmonary vein isolation and linear left atrial ablation as a single-catheter technique to achieve bidirectional conduction block: The pace-and-ablate approach

Pulmonary vein (PV) isolation has become a cornerstone for ablation of atrial fibrillation (AF). Circular mapping catheter (CMC)-guided techniques for detection of lesion gaps are challenging. The present study describes a new concept of circumferential PV ablation aiming at bidirectional conduction block based on simultaneous pacing and ablation through the tip of a single mapping/ablation catheter. A total of 147 patients with AF received circumferential PV ablation. In persistent AF, a posterior "box" lesion and a mitral isthmus line were added. All procedures were performed in sinus rhythm. Gaps within the left atrial (LA) ablation lines were detected and closed using voltage and pace mapping through the mapping/ablation catheter. Bidirectional conduction block was the procedural end point. Subsequently, the end point was validated by an independent electrophysiologist using a CMC. Procedural and radiation time measured 188 +/- 55 and 37 +/- 15 min. Bidirectional PV conduction block (lack of PV potentials and lack of LA capture) was found in 140 of 147 (95%) patients with single mapping/ablation catheter and in 138 of 147 (94%) patients with CMC. Early PV reconduction was seen in 22 of 147 (15%) patients. After 12 months follow-up, 84% of the patients were free from AF and/or atrial macro-re-entrant tachycardia. The rate of reablations was 10% and 24% for patients with paroxysmal and persistent AF, respectively. Pacing and ablation from the tip of the mapping/ablation catheter is feasible to detect and close gaps within long atrial ablation lines to consistently achieve bidirectional conduction block.

A unique iatrogenic organized left atrial tachycardia with a gap conduction in previously ablated lesions

This case concerns a 57-year-old woman with an organized left atrial tachycardia (AT) after pulmonary vein (PV) isolation. The left inferior PV (LIPV) exhibited a figure of eight tachycardia around the LIPV ostium with one loop at the anterior aspect and another at the posterior aspect, which corresponded to regular surface P waves. Although a gap ablation of fractionated electrograms changed the LIPV sequence, the atrial potentials were organized with a shortened cycle length accompanied by the same surface P-wave morphology. The elimination of the anterior loop and modification of the posterior loop after the gap ablation might have yielded that specific sequence change of the AT.

Early recovery of pulmonary vein conduction after cryoballoon ablation for paroxysmal atrial fibrillation: a prospective study

To assess the incidence of early pulmonary vein (PV) reconnection, characterize the anatomic features of the reconducting veins, and analyse the time course of their recovery in a series of consecutive patients with paroxysmal atrial fibrillation (AF) undergoing ablation with the Arctic Front Cryoballoon. We prospectively enrolled 26 patients (20 males; age 55.4 +/- 4.1) for circumferential PV cryoballoon isolation for highly symptomatic paroxysmal AF. Following isolation of all veins, we analysed PV potentials in each vein after 30 and 60 min with a circular mapping catheter. After successful electrical isolation of all 104 PV's, recurrence was observed only in three veins (2.8%) after 30 min. Two further cryoballoon applications in each of these veins lead to their isolation. These veins were still electrically disconnected at 60 min. No PV reconnection was observed in any of the other 101 veins (97.1%) at 30 and 60 min. Cryoballoon ablation of the PV's ostia is a very effective technique to achieve electrical isolation, with a very low rate of early reconnection.

Escape rhythm from a partially disconnected pulmonary vein

We present a 34-year-old patient with recurrent episodes of drug refractory paroxysmal atrial fibrillation referred for pulmonary vein (PV) isolation at our institution. During isolation of the right superior PV, a dissociated escape rhythm was observed on a portion of the PV that was disconnected, while the rest of the PV showed clear left atrium to PV conduction. This report demonstrates the rare possibility of escape PV rhythm from only partially disconnected PV, highlighting that dissociated PV rhythm does not necessarily reflect complete PV isolation.

Adenosine Triphosphate Exposes Dormant Pulmonary Vein Conduction Responsible for Recurrent Atrial Tachyarrhythmias Importance of Evaluating the Dormant Conduction During the Re-Do Ablation Procedure

A 61-year-old man suffered from atrial tachycardia (AT) following pulmonary vein isolation (PVI) treatment of atrial fibrillation. During a re-do procedure, all pulmonary veins (PVs) were isolated from the left atrium (LA) and programmed stimulation could not induce any atrial arrhythmias. Adenosine triphosphate exposed dormant PV-LA conduction at the right superior PV. PV firing during the reconnection caused AT with the same P-wave morphology as clinical AT. For 6 months after the elimination of that dormant PV conduction, the patient has been free of any AT. Evaluation of dormant PV conduction was effective in curing the recurrent AT after PVI.

Abstract 2755: Increased Efficacy of Catheter Ablation Of Atrial Fibrillation by Using Adenosine to Reveal Dormant Pulmonary Vein Conduction

Recurrences of atrial fibrillation (AF) after catheter ablation are frequently associated with recovery of conduction between the pulmonary veins (PV) and the atrium. The recovery of PV conduction could be explained by the presence of dormant conduction between the PV and the atrium. Adenosine can be used during AF ablation procedures to reveal transient re-conduction of the isolated pulmonary vein (dormant PV conduction). We prospectively evaluate the utility of iv adenosine to guide elimination of dormant PV conduction by additional radiofrequency (RF) applications during AF ablation procedures. Thirty-four consecutive patients (30 male; age 51+/−8 years) referred for catheter ablation of drug-refractory AF (Paroxysmal 31/Persistent 3) were studied. Electrical PV isolation (PVI) was performed using Irrigated-tip radiofrequency (RF) ablation and was guided by a circular mapping catheter. After PVI, the presence of dormant conduction in each vein was assessed by injection of 12 mg of adenosine. If dormant conduction was present, additional RF energy was delivered at sites of transient re-conduction. Abolition of the dormant conduction was then demonstrated by repeated injections of adenosine. The recurrence rate of arrhythmia after one procedure was evaluated. The results were compared to an historical control group comprising the previous 34 consecutive patients who underwent PVI without the use of adenosine. Electrical PVI was achieved in 100% of PV’s and all 34 patients underwent the adenosine evaluation. Dormant PV conduction was observed in 17/34 patients and could be eliminated in all by additional RF delivery. Procedural and fluoroscopy times were 163±30 and 49±13 minutes, respectively. After a mean follow-up of 8.0±3.1 months, 6/34 (18%) patients experienced AF recurrence with 28/34 (82%) remaining free of arrhythmia without the use of antiarrhythmic drugs. When compared to the 14/34 patients (41%) from the historical control group who had AF recurrence, a significant reduction was observed (P&lt;0.01). The use of adenosine to guide elimination of dormant PV conduction increases the success rate of AF ablation procedures. This needs to be evaluated in a randomized multicenter trial.

Abstract 642: Effect of Acute and Chronic Stretch on the Pulmonary Veins in Humans: Implications for Arrhythmogenic Triggers

Introduction Stretch is characteristic of most conditions predisposed to atrial fibrillation (AF). However, there is no human data on effect of atrial stretch on pulmonary veins (PV), the dominant trigger of AF Method Two groups were studied; Group A (n=12; 31±7 yrs) undergoing left sided accessory pathway ablation and Group B (n=12; 29±7 yrs) undergoing percutaneous valvuloplasty for mitral stenosis (MVA 0.9±0.3 cm 2 ). Multi-electrode basket catheter was positioned in the PVs to perform high-density mapping using NavX system to determine: proximal/ distal effective refractory period (ERP); conduction time (CT); intra-PV conduction block (CB; ≥30ms between adjacent poles) resulting in circuitous conduction during the drive (S 1 ) and pre-excited stimulus (S 2 ); and intra-PV voltage. Effect of acute stretch was determined in Group A by simultaneous RV and PV pacing and chronic stretch in Group B Results Twenty-four PVs were studied in each group. Acute stretch (Group A) resulted in ERP shortening (240±33 to 225±39 ms; p=0.03), prolonged CT with S 2 , which increased further with stretch (77±30 to 88±37ms; p=0.02). Intra-PV CB became prominent with S 2 and accentuated with stretch (40±23 to 59±32ms; p&lt;0.0001). The changes were not site specific. Left atrial volume (p=0.001) and pressure (p=0.04) were elevated in Group B. Unlike acute stretch, ERP was prolonged, conduction delayed in sinus rhythm (p=0.005) and S 1 which further accentuated with S 2 (refer Table ). Intra-PV CB was seen at S 2 . Additionally, mean bipolar voltage was reduced (0.8[0.3–3.5] mV vs 1.4[0.8–3.7] mV; p=0.005) Conclusion Acute stretch results in abbreviation of PV ERP while chronic prolongs it. Nevertheless, both cause marked PV conduction abnormalities that are pronounced with chronic stretch and extra-stimuli. Additionally, structural remodeling was seen with chronic stretch. These abnormalities implicate stretch in the milieu for re-entry and PV arrhythmogenesis in conditions predisposed to AF Electrophysiological characteristics

Further Insight into the Technique and Outcomes of “Curative” Catheter Ablation of Atrial Fibrillation

During the past decade, catheter ablation of atrial fibrillation (AF) has emerged as an important treatment option for patients with symptomatic AF refractory to ≥1 antiarrhythmic agents. Electric isolation of the pulmonary vein musculature (PVI) has been identified as the primary end point for both catheter- and surgical-based AF ablation procedures.1 What is less clear is whether the addition of “linear lesions” or ablation of atrial sites demonstrating complex atrial electrograms improves outcome for patients with paroxysmal, persistent, or long-standing persistent AF.2,3 This issue remains an area of active discussion, debate, and investigation. Article see p 269 In this issue of Circulation: Arrhythmia and Electrophysiology , Gaita et al2 report the results of a prospective single-center randomized study of 204 patients who underwent catheter ablation for treatment of paroxysmal or persistent/permanent AF. Patients were stratified according to whether they had paroxysmal (n=125) or persistent/permanent (n=79) AF and were then randomized in a 2:1 fashion to undergo PVI alone or PVI combined with a “roof line” and a “left mitral line.” Follow-up visits that included an ECG, 24-hour Holter, and an echocardiogram were set up at 1, 3, 6, 12, 18, 24, and 30 months and then every year thereafter. If a patient experienced symptoms between follow-up visits, an event monitor was prescribed. A recurrence was defined as a symptomatic or asymptomatic episode of AF or atrial flutter lasting ≥30 seconds after a 2-month blanking period. Patients who developed a recurrence after the blanking period were offered a repeat ablation procedure. The outcome of ablation was evaluated at 12 months of follow-up and at completion of the study. Each patient was followed for a minimum of 3 years. Among the 125 patients with paroxysmal AF, the single-procedure success rate at 12 months was 46% with PVI alone versus …

Katheterablation bei Vorhofflimmern: wann bereits klinisch etabliert, wann noch experimentell?

Interventional treatment for atrial fibrillation (AF) has been introduced as a therapeutic option soon after the pulmonary veins (PV) have been discovered as the dominant sources of paroxysmal atrial fibrillation (PAF). Elimination of PV conduction is the initial goal during catheter ablation in this setting. The success rate after the initial procedure varies between 60% and 85%, with > 80% after subsequent interventions. Supported by the current guidelines, interventional treatment of AF is indicated in case of symptomatic arrhythmias refractory to antiarrhythmic treatment. The introduction of the combined, stepwise approach has been another important breakthrough with regard to the treatment of chronic persistent atrial fibrillation (CAF). This strategy includes the combination of all conventional ablation strategies (pulmonary vein isolation [PVI], defragmentation, linear ablation) with the goal of AF termination by radiofrequency current. The first procedure for CAF treatment is quite frequently also only the first step toward stable sinus rhythm with a favorable outcome after AF termination (> 80% sinus rhythm). In more than half of the patients predominantly atrial arrhythmias other than AF have to be targeted in a second procedure. This approach is currently under clinical investigation and so far not "clinically established" due to the fact that it is a quite time-consuming and challenging procedure even in experienced centers. Future studies may help to identify predictors for procedure failure (e.g., left atrial size, AF duration, atrial cycle length) in order to improve patient selection. Additionally, it has to be underscored, that in PAF the relatively high recurrence rate after the first procedure still is the subject of further investigations. This aspect might be improved by the introduction of novel strategies (i.e., testing of concealed PV conduction after ablation with adenosine) or technologies (i.e., robotic navigation) for PAF ablation.

Incidence and Time Course of Pulmonary Vein Conduction Recovery Following Electrical Isolation

Incidence and Time Course of Pulmonary Vein Conduction Recovery Following Electrical Isolation