Document Detail

Atrial fibrillation and pacing algorithms.
Jump to Full Text
MedLine Citation:
PMID:  16943966     Owner:  NLM     Status:  PubMed-not-MEDLINE    
Abstract/OtherAbstract:
Pacing prevention algorithms have been introduced in order to maximize the benefits of atrial pacing in atrial fibrillation prevention. It has been demonstrated that algorithms actually keep overdrive atrial pacing, reduce atrial premature contractions, and prevent short-long atrial cycle phenomenon, with good patient tolerance. However, clinical studies showed inconsistent benefits on clinical endpoints such as atrial fibrillation burden. Factors which may be responsible for neutral results include an already high atrial pacing percentage in conventional DDDR, non-optimal atrial pacing site and deleterious effects of high percentages of apical ventricular pacing. Atrial antitachycardia pacing (ATP) therapies are effective in treating spontaneous atrial tachyarrhythmias, mainly when delivered early after arrhythmia onset and/or on slower tachycardias. Effective ATP therapies may reduce atrial fibrillation burden, but conflicting evidence does exist as regards this issue, probably because current clinical studies may be underpowered to detect such an efficacy. Wide application of atrial ATP may reduce the need for hospitalizations and electrical cardioversions and favorably impact on quality of life. Consistent monitoring of atrial and ventricular rhythm as well as that of ATP effectiveness may be extremely useful for optimizing device programming and pharmacological therapy.
Authors:
Paolo Terranova; Barbara Severgnini; Paolo Valli; Simonetta Dell'Orto; Enrico Maria Greco
Related Documents :
133196 - Comparison of the electrocardiogram and vectorcardiogram for the diagnosis of left atri...
19682166 - A novel mechanism of failure to detect atrial arrhythmias by pacemakers and implantable...
19162346 - Clinical implications of the p wave duration and dispersion: relationship between atria...
2060356 - Isolated atrial infarction in a patients with single vessel disease of the sinus node a...
8835866 - Myocyte death in heart failure.
20031606 - The 9p21 myocardial infarction risk allele increases risk of peripheral artery disease ...
Publication Detail:
Type:  Journal Article     Date:  2006-07-01
Journal Detail:
Title:  Indian pacing and electrophysiology journal     Volume:  6     ISSN:  0972-6292     ISO Abbreviation:  Indian Pacing Electrophysiol J     Publication Date:  2006  
Date Detail:
Created Date:  2006-08-31     Completed Date:  2007-07-20     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  101157207     Medline TA:  Indian Pacing Electrophysiol J     Country:  India    
Other Details:
Languages:  eng     Pagination:  163-72     Citation Subset:  -    
Affiliation:
U.O. Cardiologia e UTIC, Azienda Ospedaliera S. Paolo - Polo Universitario, Department of Medicine, Surgery and Odontoiatry, University of Milan, Italy. Paolo.Terranova@unimi.it
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Full Text
Journal Information
Journal ID (nlm-ta): Indian Pacing Electrophysiol J
Journal ID (publisher-id): Indian Pacing Electrophysiol J
ISSN: 0972-6292
Publisher: Indian Pacing and Electrophysiology Group
Article Information
Copyright: © 2006 Terranova et al.
open-access: This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
collection publication date: Season: Jul–Sep Year: 2006
Electronic publication date: Day: 1 Month: 7 Year: 2006
Volume: 6 Issue: 3
First Page: 163 Last Page: 172
ID: 1513529
Publisher Id: ipej060163-00
PubMed Id: 16943966

Atrial Fibrillation and Pacing Algorithms
Paolo Terranova, MD*
Barbara Severgnini, MD
Paolo Valli, MD
Simonetta Dell'Orto, MD
Enrico Maria Greco, MD
*U.O. Cardiologia e UTIC, Azienda Ospedaliera "S. Paolo" - Polo Universitario, Department of Medicine, Surgery and Odontoiatry, University of Milan, Italy
U. O. di Cardiologia, Presidio Ospedaliero "Causa Pia Ospedaliera Uboldo", Cernusco sul Naviglio, Azienda Ospedaliera di Melegnano, Milano, Italy
Correspondence: Address for correspondence: Dott. Paolo Terranova, MD, U. O. Cardiologia, A. O. "S. Paolo", Dept. Medicine, Surgery and Odontoiatry University of Milan, Italy. E-mail: Paolo.Terranova@unimi.it

Introduction

Atrial fibrillation is surely the most common arrhythmia in clinical practice and nowadays its incidence is increasing mainly due to the progressive ageing of population. Atrial fibrillation represents also the cardiac rhythm disorder that causes the highest number of hospitalizations [1] and is associated with higher mortality [2], major clinical complications such as heart failure, acute myocardial infarction, stroke [3], and impaired quality of life [4]. Atrial fibrillation is frequently associated with ventricular tachyarrhythmias. It has been calculated that 20% of the patients with conventional indication for cardioverter defibrillator implantation had atrial fibrillation before implant and that during the lifespan of the device more than 50% may develop atrial fibrillation [5,6]. Antiarrhythmic drugs have been widely used for cardioversion and maintenance of sinus rhythm, but they showed a limited and usually temporary efficacy [7]. As a consequence, several non-pharmacological therapies, including physiological pacing, pacing prevention algorithms, anti-tachycardia pacing therapies and low-energy internal cardioversion have been introduced to treat drug refractory patients and have been implemented in multifunction implantable devices [8].


Pacing prevention algorithms

Antiarrhythmic benefits of atrial and dual-chamber pacing versus single-chamber ventricular pacing in reducing atrial fibrillation recurrences and in preventing progression to permanent atrial fibrillation have been clearly demonstrated in large prospective trials enrolling either sinus node disease patients or unselected patients candidate for pacemaker implantation [9-11]. It has also been suggested that availability of rate responsiveness may maximize the effect of physiological pacing [12]. Pacing prevention algorithms have been introduced in order to maximize the preventive benefits of atrial pacing. Specific mechanisms involved in atrial fibrillation prevention by pacing algorithms include premature atrial contraction suppression or conditioning, with fewer chances to initiate atrial fibrillation, short-long atrial cycle prevention and maintenance of a high degree of exit block from all natural subsidiary atrial pacemakers. Several algorithms have been introduced by the different manufacturers during the last years. To summarize, they may be classified as follows: 1) dynamic sinus rhythm overdrive, 2) premature atrial beat reaction (short-long cycle prevention and ectopy overdrive), 3) post-tachycardia overdrive to prevent early recurrence of atrial fibrillation, and 4) prevention of inappropriate rate fall after exercise. The atrial pacing preference algorithm was the first evaluated, before being implemented in market released devices, as a temporary software, named "consistent atrial pacing", which could be downloaded into a conventional dual-chamber pacemaker via telemetry using a custom research telemetry device. It included a diagnostic which could be interpreted by a special Microsoft Excel spreadsheet. Diagnostic data were available also when the algorithm was switched off (suspended). The reliability and effectiveness of such algorithm was evaluated in a prospective randomized pilot study in which 61 patients with brady-tachy syndrome were enrolled and implanted with a rate responsive dual-chamber pacemaker [13]. After downloading of the algorithm, patients were randomly assigned to algorithm programming "on" or "suspended", with crossover after 1 month. Consistent atrial pacing induced an increase in atrial pacing percentage from 77 to 96%, and was associated with an 80% reduction of premature atrial contractions' number. Atrial fibrillation recurrences were not reduced in the overall population, but they significantly decreased by 42% when considering the patients in whom the atrial pacing percentage was < 90% during the algorithm "suspended" period. Algorithm tolerance was good with no severe adverse events. The atrial rate stabilization algorithm has been evaluated (alone or combined with consistent atrial pacing) in 16 patients with brady-tachy syndrome [14]. With regard to the effects on atrial fibrillation burden, 11 patients (69%) were found to benefit significantly from the consistent atrial pacing or atrial rate stabilization algorithms (reduction > 50% of atrial fibrillation burden). In detail, 7 patients were responders to both algorithms, 2 to consistent atrial pacing only, and 2 to atrial rate stabilization only.

The ability of the post-mode switching overdrive algorithm to stabilize the atrial rate after termination of treated atrial arrhythmias has been studied in 15 patients with structural heart disease and documented atrial and ventricular arrhythmias, receiving a Jewel AF device [15]. The algorithm was active in 41% of 600 spontaneous atrial tachyarrhythmia episodes. It was capable of driving and stabilizing the atrial rhythm in the presence of slow spontaneous atrial rhythm or premature atrial beats with normal atrioventricular conduction. In case of premature atrial beats with any degree of atrioventricular block, the algorithm stabilized the ventricular rate. The authors concluded that the algorithm is reliable and might be of benefit for atrial arrhythmia treatment.

Efficacy of preventive pacing algorithms has been confirmed by the preliminary results of the AF Therapy Study [16]. In 97 patients with a history of paroxysmal atrial fibrillation of at least 1 year, who had experienced at least three episodes during the last 3 months and were refractory to drug therapy, activation of four different preventive algorithms was associated with a significant improvement in all pre-selected endpoints: atrial fibrillation burden, average sinus rhythm duration, mean time in-between atrial arrhythmia episodes and number of patients free of atrial arrhythmias lasting > 1 min. All benefits were observed either in patients with or without conventional indication for pacing. Similarly, in the ADOPT trial [17], in which 320 patients were enrolled in a parallel design with randomization to algorithms on vs. off, symptomatic atrial fibrillation burden was reduced by 25% in the treatment group. On the contrary, atrial fibrillation episode number, quality of life and hospitalizations did not differ between the two randomization arms. An important criticism of ADOPT trial was that only symptomatic AF was used as an end-point.

Also, a retrospective analysis by the ADOPT investigators presented in Heart Rhythm 2004 suggested that less ventricular pacing is associated with less AF recurrence (although the results did not reach statistical significance). Concern about the actual effectiveness of prevention algorithms in improving clinical outcome has been raised by the conflicting results [18,19] of the most recently published studies in which arrhythmia burden was usually selected as the main endpoint. To explain that, the interaction with other critical factors has been claimed, first of all the atrial pacing site. It is well known that atrial pacing from the right atrial appendage is associated with a prolonged P wave duration with unfavorable effects on atrial conduction and refractoriness. Clinical studies suggest that combining prevention algorithms with interatrial septal pacing may lead to better clinical outcome [20]. Furthermore, the hemodynamic negative effects of unnecessary ventricular pacing in dual-chamber pacing systems may counterbalance the preventive role of pacing algorithms. Blanc et al. [21] demonstrated that pacing algorithms could reduce the atrial arrhythmia burden only in patients with ventricular pacing percentage < 70%. In the MOST study [22], in patients with sinus node disease, atrial fibrillation recurrences had reverse relationship with ventricular pacing percentage. Moreover, the OASES trial [23] showed that the AF Suppression algorithm was even more effective when the atrial lead was implanted in the low atrial septum. In patients with right atrial appendage leads, the algorithm reduced AF burden as measured by mode-switches by 49%, whilst in patients with low atrial septal leads, the AF burden was reduced by 70%. However, whereas the ADOPT and OASES trials showed that this AF suppression algorithm reduces AF, trials testing other algorithms have not shown a similar efficacy. The ATTEST trial [24] evaluated the efficacy of overdrive pacing, and high-rate pacing algorithms in patients with AF and an indication for pacing. There were no statistically significant differences in recurrence of symptomatic AF or in AF burden. ATP terminated 54% of atrial tachycardia episodes, but high-frequency pacing could not terminate AF. Another subsequent trial, quite similar to OASES one, the ASPECT [25], showed that pacing from the atrial septum resynchronizes the atrium and provides an antiarrhythmic effect that enhances the efficacy of the suppression algorithms.

It is very important to recognize the differences between these trials. The ADOPT [17] and OASES trials [23] tested the efficacy of a single algorithm to prevent AF, whereas ATTEST [24] tested the efficacy of 3 preventive pacing algorithms and 2 pacing algorithms designed to terminate atrial tachyarrhythmias. Moreover, the follow-up in ATTEST trial was 3 and not 6 months. Another matter with the OASES and the ASPECT trials was the crossover design. Because the beneficial effect of atrial pacing may persist, this design may have limited the observed efficacy of the pacing algorithms. Thus the difference in results between these trials may reflect differences in study design or differences in the efficacy of the algorithms used. Finally, due to high variability of atrial fibrillation recurrence patterns [26], published studies may be underpowered to demonstrate the true benefits of prevention algorithms.

In summary, 2 trials have shown that AF suppression algorithms enhances the antiarrhythmic effects of atrial pacing in patients with AF and an indication for pacing. Thus, minimizing ventricular pacing and placing the atrial lead in the septum may probably enhance the efficacy of these algorithms.


Atrial antitachycardia pacing to treat atrial tachyarrhythmias

It has been demonstrated that rapid atrial pacing delivered for treating atrial tachycardia or atrial flutter may be effective in restoring sinus rhythm in 60-90% of patients [27]. Maximal effectiveness can be usually obtained by delivering antitachycardia pacing at a rate that is slightly greater than the atrial arrhythmia rate. Delivering of some extrastimuli following a rapid pacing train may be more efficacious than overdrive atrial pacing at the same pacing cycle length in terminating atrial flutter [28]. High-frequency pacing may change atrial tachycardia in transient atrial fibrillation with later sinus rhythm restoration. Appropriate detection of atrial tachyarrhythmias and efficacy of pacing therapies in patients receiving a dual defibrillator have been evaluated in large series. Adler et al. [29] reported on 537 patients with ventricular arrhythmia implanted with the Medtronic 7250 dual defibrillator (Medtronic Inc., Minneapolis, MN, USA) who were enrolled in the Worldwide Jewel AF Study and followed on average for 1 year. Seventy-four percent had a documented history of prior atrial tachyarrhythmias. Seventy-one percent of the patients had atrial therapies enabled at some time during the follow up, allowing collection and analysis of 3500 atrial episodes from 167 patients. In the 7250 Dual Defibrillator Italian Registry [30], 105 patients were enrolled. Implant indication was represented by combination of ventricular and atrial tachyarrhythmias in 52% of patients, ventricular tachyarrhythmias only in 33%, and atrial tachyarrhythmias only in 14%. During a mean follow-up of 6 months, 863 treated atrial episodes were collected and analyzed. Gold et al. [31], on behalf of the Worldwide Jewel AF-Only Investigators, studied 146 patients with recurrent drug refractory atrial fibrillation without prior ventricular tachyarrhythmias, who were implanted with a dual defibrillator and were followed on average for 1 year. During the follow-up 4913 treated episodes were available for stored electrogram analysis and therapy efficacy evaluation. Atrial tachyarrhythmia detection was very good in all the studies with a positive predictive value of atrial detection ranging from 91 to 99%. The most common reasons of inappropriate detection were represented by far-field R-wave oversensing during sinus rhythm or cluster of premature atrial contractions. Reprogramming of atrial sensitivity allowed in some case avoidance of inappropriate detection due to far-field R-wave oversensing. Sensitivity of atrial tachycardia and fibrillation detection and validation of continuous detection of atrial tachyarrhythmias have been specifically addressed by Swerdlow et al. [42] who performed 80 Holter recordings with telemetered atrial electrograms in 58 patients, implanted because of combination of atrial and ventricular arrhythmias. Continuous detection of atrial tachyarrhythmia could be demonstrated in 96% of patients with spontaneous episodes. Atrial sensitivity for arrhythmia detection was 100%. It is worthwhile to stress that the atrial arrhythmia detected at very early onset was very commonly a well organized atrial tachycardia. Among 2380 episodes in the worldwide series, 63% were classified as atrial tachycardia (mean atrial cycle 278 ± 56 ms) and 37% as atrial fibrillation (mean cycle 204 ± 35 ms). In the Italian Registry, among 863 atrial episodes, 53% were automatically classified by the device as atrial tachycardia and 47% as atrial fibrillation. After revision of the stored data, among 843 appropriately detected episodes, 55% were clinically classified as atrial fibrillation and 45% as atrial tachycardia. In the AF-Only group, among 3116 episodes treated by antitachycardia pacing, 67% were classified as atrial tachycardia.

Efficacy of antitachycardia pacing therapy in the three series is reported in Table 1 [29-31]. The efficacy was estimated in two ways: 1) crude estimate, defined as the proportion of successful terminations out of the total number of treated episodes; 2) adjusted estimate, using the generalized estimate equation method [30] which allows adjusting estimate for multiple episodes within a patient through a correlation structure between episodes and patients.

In the worldwide study [29-31], a subanalysis performed to compare the efficacy of burst+ vs. ramp therapy for atrial tachycardia did not find any significant difference between the two therapies. An history of atrial flutter was the only independent predictor of pacing efficacy for atrial tachycardia, while no independent predictors could be identified for atrial fibrillation. No comparison was feasible between burst+ or ramp and high-frequency burst because the last was usually applied after unsuccessful delivery of burst+ or ramp therapy.

Pooling all antitachycardia pacing therapies (burst+, ramp and 50 Hz burst), their efficacy consistently increased as far as atrial arrhythmia cycle lengthened. As a matter of fact, in the Italian Registry, while the relationship between efficacy of atrial burst+ and ramp vs. atrial cycle length was very high (r2 = 0.85, p < 0.001), the relationship between efficacy of 50 Hz burst and atrial cycle length was very poor, with a trend toward a reverse correlation (r2 = 0.31, p < 0.05). Such a difference could be explained by taking into account the mechanisms of action of different antitachycardia pacing techniques. During overdrive pacing, the wavefront of pacing stimulus enters the reentrant pathway in the antidromic and orthodromic direction. The antidromic wavefront blocks by collision the arrhythmia wavefront, while the orthodromic wavefront may either reset the tachycardia or stop it, when early enough to be blocked in a refractory area. Slower tachycardias, due to a wider excitable gap, may be more easily terminated in this way. Termination of atrial tachyarrhythmias by high-frequency pacing is typically preceded by tachycardia acceleration, which becomes unable to be sustained, hence resulting in arrhythmia termination and sinus rhythm restoration. It has been hypothesized that high-frequency pacing induces a new faster reentrant circuit which is unable to sustain itself [34]. This mechanism looks independent of the arrhythmia cycle.

Looking at individual patients, random and wide distribution of median atrial cycles at onset during the follow-up was observed in the majority of them. A subgroup showed a narrow Gaussian distribution along either a fast (200 ms) or a slow band (250 ms). Antiarrhythmic drugs have been demonstrated to be capable of modifying atrial cycle profile. Antiarrhythmics may modify the electrophysiological properties of the atria and the arrhythmia organization pattern by lengthening the mean atrial arrhythmia cycle and by widening the temporal excitable gap [35-37]. Dijkman and Wellens [38] demonstrated that atrial arrhythmias in defibrillator patients with structural heart disease, receiving class III antiarrhythmic drugs, frequently had longer cycle lengths than atrial fibrillation. In fact, among 600 spontaneous episodes, atrial fibrillation was diagnosed in 19%, fast polymorphic atrial tachycardia in 20%, fast monomorphic atrial tachycardia in 57%, and slow atrial tachycardia in 4%. Drug-induced atrial cycle length changes may impact on atrial antitachycardia pacing therapy efficacy. In spite of that, in the AF-Only series there were no drugs that were independent predictors of therapy efficacy.

Finally, increasing the delay from arrhythmia detection to therapy delivery was associated with a significant reduction in efficacy. Optimal delay has been identified in less than 5 min in the Worldwide Study and in less than 1 min in the Italian Registry. That was probably due to the fact that the majority of atrial tachyarrhythmias accelerated in few minutes after onset. Considering that slower arrhythmias can be more easily treated by pacing techniques, a short delay in therapy delivery should be recommended. The efficacy of 50 Hz burst on atrial fibrillation may be a matter of debate. Wide local capture of atrial fibrillation has been documented [39]. Data from canine studies suggested that high-frequency pacing could accelerate the local atrial fibrillation cycle length and destabilize the reentrant rhythm so that destabilized atrial fibrillation could be converted to sinus rhythm in some cases. Anyway, in humans termination of persistent atrial fibrillation by high-frequency pacing could never be demonstrated [40,41]. High-frequency pacing may terminate induced atrial fibrillation during electrophysiological study with a 33% efficacy rate [34] and atypical atrial flutter with a 60% efficacy rate [41]. In selected cases, local capture of new-onset atrial fibrillation and entrainment of a relatively large area of the atria [42] could have destabilized the arrhythmia by reducing the number of wavelets of the random reentry, hence preventing arrhythmia sustenance. Anyway, considering that arrhythmia classification is based on atrial activity at atrial lead site, misclassification of atrial tachycardia as atrial fibrillation cannot not be excluded. Furthermore, some episodes may have terminated spontaneously after therapy delivery [43].

The ASPEN-ICD and ASSIST trials will probably give more data about these new perspectives. They will test the algorithm in patients with ICDs. The former will determine if the first episodes of AF can be prevented by the algorithm, whereas the latter will test if this algorithm prevents AF in patients who have a history of atrial arrhythmia.

Safety of antitachycardia pacing therapy was excellent since no ventricular arrhythmia induction was observed in any case after antitachycardia pacing delivery. These data suggest that, on a large scale, these algorithms would presumably be safe, and that it would be necessary to better determine how effective atrial ATP is, and whether it would reduce hispitalizations and/or electrical or pharmacological cardioversions and thereby improve quality-of-life.


Conclusions

As stated in the discussed trials, pacing prevention algorithms should probably be better and further evaluated, before having a definitive and comprehensive answer on their utility. Clinical studies showed inconsistent clinical benefits of the algorithms, although they reduce atrial fibrillation triggers such as premature atrial complexes, thus preventing short-long cycle phenomenon. Factors which may be responsible for neutral results include: 1) high atrial pacing percentage in conventional DDDR, 2) non-optimal atrial pacing site, 3) deleterious effects of high percentages of ventricular pacing, and 4) inappropriate study design and endpoint selection. Variability of atrial arrhythmia recurrence patterns and onset mechanisms suggest individual programming of prevention algorithms by using data stored in the device memory. Atrial antitachycardia pacing is an effective tool to treat atrial tachyarrhythmias and it may stop nearly 50% of arrhythmia episodes. In particular, all previously described data are more related to atrial tachycardia reduction than to atrial fibrillation decrease. Delivery of atrial therapies early after arrhythmia onset and on more organized arrhythmias may improve success rate. Associated use of antiarrhythmic drugs, mainly propafenone and flecainide, may further increase effectiveness by lengthening atrial arrhythmia cycle.

Effective antitachycardia pacing therapies may reduce atrial fibrillation burden, but conflicting evidence does exist as regards this issue, probably because current clinical studies may be underpowered to detect such an efficacy. Consistent monitoring of atrial and ventricular rhythm as well as that of antitachycardia pacing effectiveness may be extremely useful for optimizing device programming and pharmacological therapy. At present the efficacy of pacing algorithms to prevent AF is by no means something that has been proved beyond reasonable doubt, so that more large-scale prospective trials are needed to answer this question. Our information is currently based on small trials and any attempt to extrapolate these data to the general population will probably produce inaccurate results. Clinical endpoints should be further investigated in future studies.


References
Wolf PA,Mitchell JB,Baker CS,et al. CASH Investigators. Impact of atrial fibrillation on mortality, stroke and medical costsArch Intern Med 1998;158:229–234. [pmid: 9472202]
Kannel WB,Abbot RD,Savage DD,et al. Epidemiologic features of chronic atrial fibrillatioN Engl J Med 1982;306:1018–1022. [pmid: 7062992]
Wolf PA,Abbot RD,Kannel WB. Atrial fibrillation as an independent risk factor for stroke: the Framingham studyStroke 1991;22:983–988. [pmid: 1866765]
Hamer ME,Blumenthal JA,McCarthy EA,et al. Quality of life assessment in patients with paroxysmal atrial fibrillation or paroxysmal supraventricular tachycardiaAm J Cardiol 1994;74:826–829. [pmid: 7942563]
Schmitt C,Montero M,Melichercik J,et al. Significance of supraventricular tachyarrhythmias in patients with implanted pacing cardioverter defibrillatorsPacing Clin Electrophysiol 1998;17:295–302. [pmid: 7513854]
Santini M,Ricci R. Dual chamber implantable cardioverterdefibrillators: should they always be preferred to single chamber cardioverter-defibrillators?Cardiac Electrophysiology Review 2001;5:18–23.
Suttorp MJ,Kingma JH,Koomen EM,et al. Recurrence of paroxysmal atrial fibrillation or flutter after successful cardioversion in patients with normal left ventricular functionAm J Cardiol 1993;71:710–713. [pmid: 8447270]
Ricci R,Pignalberi C,Disertori M,et al. Efficacy of a dual chamber defibrillator with atrial antitachycardia functions in treating spontaneous atrial tachyarrhythmias in patients with life-threatening ventricular tachyarrhythmiasEur Heart J 2002;23:1471–1479. [pmid: 12208228]
Andersen HR,Nielsen JC,Thomsen PE,et al. Long-term follow up of patients from a randomised trial of atrial versus ventricular pacing for sick-sinus syndromeLancet 1997;350:1210–1206. [pmid: 9652562]
Skanes AC,Krahn AD,Yee R,et al. Progression to chronic atrial fibrillation after pacing: the Canadian Trial of Physiologic PacingJ Am Coll Cardiol 2001;38:167–172. [pmid: 11451268]
Lamas GA,Lee KL,Sweeney MO,et al. Mode Selection Trial in Sinus Node Dysfunction. Ventricular pacing or dual chamber pacing for sinus node dysfunctionN Engl J Med 2002;346:1854–1862. [pmid: 12063369]
Sutton R. Is rate response superior to single rate pacing in atrial arrhythmia control?Europace 1999;1:211–212. [pmid: 11220555]
Ricci R,Santini M,Puglisi A,et al. Impact of consistent atrial pacing algorithm on premature atrial complexe number and paroxysmal atrial fibrillation recurrences in bradytachy syndrome: a randomized prospective cross over studyJ Interv Card Electrophysiol 2001;5:33–44. [pmid: 11248773]
Boriani G,Biffi M,Padeletti L,et al. Effects of consistent atrial pacing and atrial rate stabilization, two pacing algorithms to suppress recurrent paroxysmal atrial fibrillation in brady-tachy syndromeEur Heart J 2001;3(Suppl P):P7–P15.
Dijkman B,Wellens HJ. Merits and limitations of the mode switching rate stabilization pacing algorithms in the implantable cardioverter defibrillatorJ Interv Card Electrophysiol 2001;5:309–318. [pmid: 11500586]
Camm J. AF Therapy Study: preventive pacing for paroxysmal atrial fibrillation. (abstr)Pacing Clin Electrophysiol 2002;25:554.
Carlson MD,Ip J,Messenger J,et al. A new pacemaker algorithm for the treatment of atrial fibrillation. Results of the Atrial Dynamic Overdrive Pacing Trial (ADOPT)J Am Coll Cardiol 2003;42:627–633. [pmid: 12932592]
Savelieva I,Camm J. The results of pacing trials for the prevention and termination of atrial tachyarrhythmias: is there any evidence of therapeutic breakthrough?J Interv Card Electrophysiol 2003;8:103–115. [pmid: 12766501]
Israel CW,Hohnloser SH. Pacing to prevent atrial fibrillationJ Cardiovasc Electrophysiol 2003;14:S20–S26. [pmid: 12950513]
Padeletti L,Pieragnoli P,Ciapetti C,et al. Randomized crossover comparison of right atrial appendage pacing versus interatrial septum pacing for prevention of paroxysmal atrial fibrillation in patients with sinus bradycardiaAm Heart J 2001;142:1047–1055. [pmid: 11717611]
Blanc JJ,De Roy L,Mansourati J,et al. PIPAF Investigators. Atrial pacing for prevention of atrial fibrillation: assessment of simultaneously implemented algorithmsEuropace 2004;6:371–379. [pmid: 15294260]
Sweeney MO,Hellkamp AS,Ellenbogen KA,et al. Mode Selection Trial Investigators. Adverse effect of ventricular pacing on heart failure and atrial fibrillation among patients with normal baseline QRS duration in a clinical trial of pacemaker therapy for sinus node dysfunctionCirculation 2003;107:2932–2937. [pmid: 12782566]
DeVoogt WG,De Vusser P,Lau CP,et al. OASES trial, Overdrive Atrial Septal Stimulation in patients with paroxysmal atrial fibrillation and class I and 2 pacemaker indication, Late Breaking Clinical TrialsNASPEMay 17, 2003
Lee MA,Weachter R,Pollak S,et al. ATTEST Investigators. The effect of atrial pacing therapies on atrial tachyarrhythmia burden and frequency: results of a randomized trial in patients with bradycardia and atrial tachyarrhythmias J Am Coll Cardiol 2003;41:1926–1932. [pmid: 12798559]
Padeletti L,Purerfellner H,Adler S,et al. Atrial septal lead placement and atrial pacing algorithms for prevention of paroxysmal atrial fibrillation: ASPECT study resultsPacing Clin Electrophysiol 2002;25:687.
Ricci R,Santini M,Ricci R,et al. Atrial tachyarrhythmia recurrence temporal patterns in bradycardia patients implanted with antitachycardia pacemakersJ Cardiovasc Electrophysiol 2004;15:44–51. [pmid: 15028071]
Peters RW,Shorofsky SR,Pelini M,et al. Overdrive atrial pacing for reversion of atrial flutter: comparison of postoperative with nonpostoperative patientsAm Heart J 1999;137:100–103. [pmid: 9878941]
Hii JT,Mitchell B,Duff HJ,et al. Comparison of atrial overdrive pacing with and without extrastimuli for termination of atrial flutterAm J Cardiol 1992;70:463–467. [pmid: 1642184]
Adler SW,Wolpert C,Warman EN,et al. Worldwide Jewel AF Investigators. Efficacy of pacing therapies for treating atrial tachyarrhythmias in patients with ventricular arrhythmias receiving a dual chamber implantable cardioverter defibrillatorCirculation 2001;104:887–892. [pmid: 11514374]
Ricci R,Pignalberi C,Disertori M,et al. Antitachycardia pacing therapy to treat spontaneous atrial tachyarrhythmias: the 7250 Dual Defibrillator Italian RegistryEur Heart J 2001;3(Suppl P):P25–P32.
Gold MR,Sulke N,Schwartzman DS,et al. Worldwide Jewel AF-Only Investigators. Clinical experience with a dual chamber implantable cardioverter defibrillator to treat atrial tachyarrhythmiasJ Cardiovasc Electrophysiol 2001;12:1247–1253. [pmid: 11761411]
Swerdlow CD,Schols W,Dijkman B,et al. Worldwide Jewel AF Investigators. Detection of atrial fibrillation and flutter by a dual-chamber implantable cardioverter-defibrillatorCirculation 2000;101:878–885. [pmid: 10694527]
Liang KY,Zeger SL. Longitudinal data analysis using generalized linear modelsBiometrika 1986;73:13–22.
Mehra R,Mongeon L. Santini MTermination of atrial tachyarrhythmias by pacing techniquesProgress in clinical pacing 1996Armonk, NY: Futura Publishing Company; :491–502.
Biffi M,Boriani G,Bronzetti G,et al. Electrophysiological effects of flecainide and propafenone on atrial fibrillation cycle and relation with arrhythmia terminationHeart 1999;82:176–182. [pmid: 10409531]
Wijffels MC,Dorland R,Mast F,et al. Widening of the excitable gap during pharmacological cardioversion of atrial fibrillation in the goat: effects of cibenzoline, hydroquinidine, flecainide, and d-sotalolCirculation 2000;102:260–267. [pmid: 10889140]
Yu WC,Chen SA,Lee SH,et al. Tachycardia-induced change of atrial refractory period in humans: rate dependency and effects of antiarrhythmic drugsCirculation 1998;97:2331–2337. [pmid: 9639377]
Dijkman B,Wellens HJ. Diagnosis and therapy of atrial tachyarrhythmias in the dual chamber implantable cardioverter defibrillatorJ Cardiovasc Electrophysiol 2000;11:1206–1207. [pmid: 11083240]
Pandozi C,Bianconi L,Villani M,et al. Local capture by atrial pacing in spontaneous chronic atrial fibrillationCirculation 1997;95:2416–2422. [pmid: 9170405]
Paladino W,Bahu M,Knight BP,et al. Failure of single- and multisite high-frequency atrial pacing to terminate atrial fibrillationAm J Cardiol 1997;80:226–227. [pmid: 9230170]
Giorgberidze I,Saksena S,Mongeon L,et al. Effects of high frequency atrial pacing in atypical atrial flutter and atrial fibrillationJ Interv Card Electrophysiol 1997;1:111–123. [pmid: 9869959]
Kirchhof C,Chorro F,Scheffer GJ,et al. Regional entrainment of atrial fibrillation studied by high-resolution mapping in open-chest dogsCirculation 1993;88:736–749. [pmid: 8339434]
Mitchell AR,Spurrell PA,Cheatle L,et al. Effect of atrial antitachycardia pacing treatments in patients with an atrial defibrillator: randomised study comparing subthreshold and nominal pacing outputsHeart 2002;87:433–477. [pmid: 11997413]

Article Categories:
  • Reviews

Keywords: Antitachycardia, Atrial fibrillation, Pacing, Prevention algorithms.

Previous Document:  Single-chamber versus dual-chamber implantable cardioverter defibrillators: do we need physiologic p...
Next Document:  Quality of life in patients with implantable cardioverter defibrillators.