Atrial Pacing For Prevention Research Articles

Right atrial preventive and antitachycardia pacing for prevention of paroxysmal atrial fibrillation in patients without bradycardia: a randomized study

To investigate the efficacy of preventive and antitachycardia pacing (ATP) in patients with symptomatic paroxysmal atrial fibrillation (AF) without bradyarrhythmias. In this randomized cross-over pilot study, we randomized 38 symptomatic paroxysmal AF patients 'without' bradyarrhythmias to atrial pacing lower rate 70 ppm and prevention and ATP therapies ON or to atrial pacing lower rate 34 ppm and prevention and ATP therapies OFF during 12 weeks with a 4 week washout period in between. The atrial lead was preferably placed in the inter-atrial septum. Antiarrhythmic drugs were continued during the study. Primary endpoint was AF burden. Mean age was 62 +/- 9 years and 27 (71%) patients had lone AF. Septal lead placement was accomplished in 26 (68%) patients. During the treatment ON, there was a trend for AF burden reduction [from median 3.3% (1.0-15.2) to 2.4% (0.2-12.2), P = 0.06, reduction 27%]. If septal lead placement was accomplished, AF burden reduction was statistically significant [44% reduction, from median 2.5% (1.0-8.0) to 1.4% (0.2-8.4), P = 0.03]. Quality of life and symptoms did not change, also not in the septal group. A hybrid therapy of preventive and ATP pacing and antiarrhythmic drugs may significantly reduce but not abolish AF burden if septal pacing is realized.

Clinical application of pacemakers in atrial tachyarrhythmias

The diagnostic programmes of modern pacemakers have increased our knowledge of atrial tachyarrhythmias (ATAs) in chronically paced patients. These programmes also support the evaluation of the effects of pharmacological treatment of ATAs. The success of interruption and/or prevention of ATAs with pacemakers depends strongly on the diagnostic accuracy and the properties of the pacing algorithms, their individual programming and the site and configuration of the pacing leads. Atrial septum pacing can be beneficial in patients with paroxysmal atrial fibrillation and prolonged P wave duration. Recent large-scale studies on preventive and interruptive atrial pacing of ATAs show modestly positive or no results. Therefore, atrial pacing therapy for ATAs should be considered cautiously, serving as an adjuvant to pharmacological treatment rather than as a primary intervention. This also applies for pacing interventions for ATAs in cardiac resynchronisation therapy. The pacemaker algorithms for the detection of ATAs and atrial lead configuration are crucial for the success of pacemaker-mediated prevention or interruption of ATAs. The success of these interventions is dependant on future improvements of pacemaker technology. (Neth Heart J 2008;16(Suppl1):S20-S24.).

Increased base rate of atrial pacing for prevention of atrial fibrillation after implantation of a dual-chamber pacemaker: insights from the Atrial Overdrive Pacing Study

Different pacing sites and various algorithms have been utilized to prevent atrial fibrillation (AF) in pacemaker recipients. However, the optimal pacing rate settings have not yet been established. In this randomized, prospective, multicentre, single-blinded, cross over study, rate-adaptive pacing at a high base rate (BR) in patients, age 60 years or above, or a history of paroxysmal AF, who underwent dual-chamber (DDD) pacemaker implantation for standard pacing indications, was evaluated for prevention of AF. In the study cohort of 145 patients implanted with DDD pacemakers with a programmable rest rate (RR) feature, the BR/RR settings were sequentially but randomly adjusted as follows: 60 bpm/Off for the baseline quarter (initial 3 months) and then to either 'A-B-C' or 'C-B-A' settings (A = 70/65 bpm, B = 70/Off, C = 80/65 bpm) for the subsequent quarters each of 3 months duration. Data on automatic mode switch episodes, device diagnostics, and a questionnaire evaluating pacemaker awareness and palpitations were collected. Ninety-nine patients, mean age 77 +/- 10 years, who completed the study protocol and followed for 12 months did not show significant differences in the number of mode switch episodes between any settings used. The percentage of atrial pacing was lower during baseline pacing compared to settings A, B, and C (P < 0.0001). Setting C produced a higher percentage of atrial pacing than A and B (P < 0.01). Although a higher percentage of atrial pacing correlated with a lower incidence of mode switch episodes, there was no statistically significant difference in the number of mode switch episodes between settings A, B, and C. There were no significant differences in the questionnaire scores relating to pacemaker awareness or palpitation. Overdrive single-site pacing in the right atrium achieved by programming analysed settings in the present study did not reduce AF as assessed by mode switch episodes. Additionally, no change in the symptoms of arrhythmia or awareness of pacing was seen.

Optimization of Pacing Algorithms to Prevent and Treat Supraventricular Tachyarrhythmias

Preventive atrial pacing and antitachycardia pacing have been proposed for the treatment of atrial fibrillation and associated arrhythmias in patients with indications for device implantation. Preventive algorithms provide overdrive atrial pacing, reduction of atrial premature beats, and prevent short-long atrial cycles with good patient tolerance. However, clinical trials testing preventive algorithms have shown contradictory results, possibly because of different trial designs, end points and patient populations. Factors probably responsible for neutral results include an already high atrial pacing percentage with the conventional DDDR mode, suboptimal atrial pacing site, and the deleterious effects of high percentages of right ventricular apical pacing. Atrial antitachycardia pacing therapies are effective in treating organized atrial tachyarrhythmias (that precede atrial fibrillation), mainly when delivered early after the onset particularly if the tachycardia is relatively slow. Antitachycardia pacing therapies might influence atrial fibrillation burden, but clinical studies have shown conflicting results about this issue. Consistent monitoring of atrial and ventricular rhythm including progression to persistent forms of atrial arrhythmias, variability of atrial arrhythmia recurrence patterns and onset mechanisms as well as antitachycardia pacing efficacy should be recorded in the stored device memory and used for optimal individual programming of these new functions.

Long term management of atrial arrhythmias in young patients with sick sinus syndrome undergoing early operation to correct congenital heart disease

The objective of our study was to evaluate the clinical outcome of patients with operated congenital heart disease (CHD), post-operative sinus node dysfunction and atrial tachyarrhythmias (AT) who had a new generation of DDDRP pacemakers (Model AT501, Medtronic Inc., MN, USA) able to deliver preventive atrial pacing and antitachycardia pacing (ATP) therapies. Fifteen CHD patients (mean age 17+/-9 years, eight after Mustard operation, five after extracardiac Fontan operation and two after atrial septum repair) received a dual-chamber pacemaker with transvenous (eight patients) or epicardial leads (seven patients). In the year before implantation, all patients had symptomatic AT (palpitations), eight patients required hospitalization and five required electrical cardioversion. Pacing prevention algorithms were enabled in all patients, and ATP therapies in six patients. During a mean follow-up of 30 months (range 24-44), three patients (two Fontan, one Mustard) died of CHF, whereas AT required hospitalization in three patients (two Fontan, one atrial septum repair). Only seven patients had symptomatic AT. One hundred and twenty-five AT episodes were treated by ATP in three patients, with an overall termination efficacy of 43.2%. In one patient, atrial lead noise induced inappropriate AT detection that resulted in ATP delivery. Several AT episodes were not treated owing to their very short duration, atrial undersensing, or 1:1 atrioventricular conduction. Our experience with antitachycardia pacemakers in CHD patients with post-operative sick sinus syndrome after biventricular correction or palliation shows that these devices are safe and that atrial pacing may play a role in AT prevention and treatment.

Right atrial overdrive pacing for prevention of symptomatic refractory atrial fibrillation

Our aim was to investigate whether right atrial overdrive pacing is effective for the prevention of atrial fibrillation (AF) in patients without bradyarrhythmias. Patients with symptomatic paroxysmal or persistent AF refractory to at least two Class I or III antiarrhythmic drugs and without bradyarrhythmias were included. Successful therapy was defined as the combination of (a) a reduction of AF burden with or without AAD use >75%, (b) total AF burden < or =5% per year, and (c) less than one electrical cardioversion per year. Lower rate was set at 70 b.p.m. Additional AF prevention and termination features were used in case of no success. After a median follow-up of 18 (10-55) months, therapy was effective in 19 of the 36 included patients (53%). In 74% of the successfully treated patients, additional antiarrhythmic drugs were used. In successfully treated patients, the AF burden was reduced from 15% (5-100%) to 0% (0-4%). Multivariate analysis showed that the concomitant use of a Class I or III antiarrhythmic drug, a lower AF burden before implantation and the use of an angiotensin converting enzyme inhibitor were predictors of successful therapy. Right atrial overdrive pacing in combination with antiarrhythmic drugs seems an attractive treatment option in drug refractory symptomatic AF patients.

Effectiveness of triple-site triggered atrial pacing for prevention of atrial fibrillation after coronary artery bypass graft surgery

Recently, several temporary multisite pacing methods have been developed for prevention of postoperative atrial fibrillation (AF). In this study, we evaluated the effect of triple-site temporary triggered pacing in the AAT mode on the development of AF in patients undergoing coronary artery bypass graft (CABG) at high risk for developing postoperative AF. A total of 70 patients undergoing CABG were randomly assigned either to pacing group (study group, n = 35 patients) or to no pacing group (control group, n = 35 patients). The external pacemaker was programmed to pace at the atrial triggered mode at a lower rate of 40 beats/min for 4 days. Atrial fibrillation, defined as lasting > 30 s, occurred in 4 patients (11.4%) in the study group and in 16 patients (45.7%) in the control group (p = 0.003). Sustained AF, defined as AF lasting > 10 min, also was observed less frequently in the study group than in the control group (11.6 vs. 37.1%, p = 0.024). Triple-site triggered atrial pacing was observed to reduce the incidence of AF by 75% and the incidence of sustained AF by 69%. We believe that multiple-site temporary pacing in the triggered mode is an effective way of preventing postoperative AF. This technique may be used especially in patients at high risk of developing AF.

Pacemaker Prevention Therapy for the Control of Drug-Refractory Paroxysmal Atrial Fibrillation: Reliability of Pacemaker Diagnostics and a Long Term Follow-Up With an Implantable Device for Atrial Prevention Pacing Therapy

Pacemaker Prevention Therapy for the Control of Drug-Refractory Paroxysmal Atrial Fibrillation: Reliability of Pacemaker Diagnostics and a Long Term Follow-Up With an Implantable Device for Atrial Prevention Pacing Therapy

Connection between efficacy of atrial fibrillation preventive pacing algorithms and atrial pacing ratio

The purpose of the study was to evaluate efficacy of main pacing algorithms for prevention of atrial fibrillation (AF) atrial pacing ratio. Methods In 17 patients (13 male, 4 female), mean age 67±6,4 years with conventional pacing indications and documented paroxysmal AF implantation of DDDRP pacemakers (11 ELA, 6 Vitatron) were performed. AF prevention algorithms were activated on 3-7th day after operation and were adopted if necessary every follow-up visit according individual mechanisms of AF onset. Each patient was programmed and evaluated at least every 3 months during 11,5±6,8 month period. We compared quantity of AF episodes/daily, AF episode duration, total AF burden (% of storage period), share of paced atrial rhythm in early (first 6 months after implantation – phase A) and late postoperational period (6-12th month after implantation – phase B). Results In 6 cases during first 3 months radiofrequency AV junction ablation was performed because persistent AF paroxysms with poor tolerability. The number of AF episodes/daily during first 3-6 months did not differ significantly between both groups (3,9 ± 5,8 vs. 2,8 ± 2,3, p=0,25) as not the atrial pacing ratio (58,6 ± 39,3% vs. 63,7 ± 25,1%, p=0,13). Average AF episode duration (171,6±99,3 min vs.105,2±74,4 min, p<0.05) and total AF burden (23,7 ± 19,0% vs. 9,2 ± 14,7%, p<0,01) significantly reduced in phase B after initial adaptation of AF-prevent algorithms. Symptomatic improvement was reported by all patients, no patient experienced pacemaker dysfunction. Conclusion AF episode duration and total AF-burden can be significantly reduced by using preventive pacing algorithms in patients with paroxysmal AF as a result of overdrive pacing. However, increase of atrial pacing ratio hardly could be a criteria of properly selected AF-prevent algorithm. Therefore, further studies to determine precise recommendations for implementation of AF-prevent algorithms needed.

Dual Site Right Atrial Pacing can Improve the Impact of Standard Dual Chamber Pacing on Atrial and Ventricular Mechanical Function in Patients with Symptomatic Atrial Fibrillation: Further Observations from the Dual Site Atrial Pacing for Prevention of Atrial Fibrillation Trial

The effects of atrial pacing mode on atrial and ventricular function in patients with atrial fibrillation (AF) and bradycardia have not been evaluated. We evaluated atrial and ventricular function during randomization to support pacing (SP), high right atrial pacing (HRA), and dual site right atrial pacing (DAP). Seventy-nine patients (66 +/- 12 yr, 46 male) with standard pacing indications and symptomatic AF were randomized to each of three pacing modes (DAP, HRA, SP) for 6 months in a crossover design. Echocardiographic studies were performed at enrollment and the end of each mode. Paired comparisons of atrial and ventricular function parameters were performed between each pacing mode and baseline. HRA pacing in DDDR mode resulted in increased left ventricular (LV) end systolic volume (78 +/- 42 vs. 60 +/- 31 ml, p = 0.001) and reduced LV ejection fraction (44 +/- 14 vs. 50 +/- 11%, p = 0.007) compared to baseline. These parameters did not change during DAP. DAP resulted in increased peak A wave velocity (75 +/- 19 vs. 63 +/- 23 cm/s, p = 0.003) and atrial filling fraction compared to baseline (0.47 +/- 0.15 vs. 0.38 +/- 0.13, p = 0.005). Atrial and ventricular function were similar between control and SP. DAP, but not HRA or SP, improved left atrial (LA) function in patients with AF and bradycardia. HRA pacing in DDDR mode resulted in LA dilatation and deterioration of LV function which was not observed with DAP.

Atrial fibrillation: profit from cardiac pacing?

The impact of cardiac pacing on the prevention of atrial fibrillation is under scientific investigation. Several prospective randomised clinical trials have reported that atrial-based "physiologic" AAI(R)- or DDD(R)-pacing is associated with a lower incidence of paroxysmal and permanent atrial fibrillation than single-chamber ventricular pacing in patients with a conventional pacemaker indication. However, it is still uncertain whether atrial pacing itself has independent antiarrhythmic properties. In contrast, right ventricular pacing is considered to promote atrial fibrillation, even in preserved AV synchrony during dual-chamber pacing. The electrical secondary prevention of atrial fibrillation is mainly based on variations of the atrial pacing site and sophisticated preventive pacing algorithms incorporated in the pacemaker software. Dual-site right atrial and biatrial pacing were reported to exhibit modest to no benefit for the prevention of atrial fibrillation, whereas septal pacing and specific preventive pacing algorithms have been demonstrated to reduce the incidence of atrial fibrillation in a number of clinical trials. However, the role of septal pacing and preventive pacing algorithms still has to be clarified since, overall, study results have been inconsistent so far. One of the main goals of future investigations should be the identification of responder groups of preventive pacing concepts. In clinical practice, the efficacy of pacing algorithms and septal pacing has to be determined in the individual case. These options should be taken into account in patients with symptomatic bradycardia as the indication for cardiac pacing and, in addition, symptomatic atrial fibrillation.

7.4 Outcome of preventive atrial pacing on recurrences of atrial fibrillation

7.4 Outcome of preventive atrial pacing on recurrences of atrial fibrillation

7.4 Outcome of preventive atrial pacing on recurrences of atrial fibrillation

7.4 Outcome of preventive atrial pacing on recurrences of atrial fibrillation

7.4 Outcome of preventive atrial pacing on recurrences of atrial fibrillation

7.4 Outcome of preventive atrial pacing on recurrences of atrial fibrillation

The Role of Multisite Atrial Pacing in Rhythm Control in AF: Insights from Sub‐analyses of the Dual Site Atrial Pacing for Prevention of Atrial Fibrillation Study

Novel pacing modes are being proposed for the prevention or reversion of atrial fibrillation (AF). High right atrial (RA) pacing and septal pacing have not individually reduced arrhythmic events in patients with AF in controlled trials. The DAPPAF trial compared the effectiveness of overdrive high right atrial single and dual site right atrial pacing as compared to demand pacing in prevention of recurrent symptomatic AF in patients with AF &amp; bradyarrhythmias. Methods: From September 1996 to November 2000, 120 patients with documented symptomatic AF were enrolled and followed in a prospective randomized single blind crossover multicenter trial. 73 males &amp; 45 females, mean age 66 ± 11 yrs with recurrent symptomatic AF (paroxysmal in 82 pts, persistent &gt;72 hrs in 30 pts &amp; persistent &gt;30 days in 6 pts) were enrolled. Baseline AF event frequency was ≥1/day in 40 pts, 1/week in 43 pts, &lt;1/week in 30 pts, &amp; unknown in 5 pts. Patients were implanted with dual site right atrial pacing systems and randomly assigned to six‐month treatment periods in overdrive dual, overdrive single or demand pacing. Three primary endpoints (time to first AF recurrence, patient quality of life &amp; tolerance/safety) and several secondary endpoints (device detected sustained AF, atrial &amp; ventricular function indices, &amp; composite endpoints) were examined. Results: Only DAP was significantly effective in preventing recurrent AF and prolonging time to first symptomatic AF recurrence in the presence of class 1 &amp; 3 antiarrhythmic drug therapy; it was more effective than H.A. pacing in reducing asymptomatic AF event frequency; DAY alone prevented left ventricular and left atrial dilatation seen with D'ETRE pacing in this population due to improved left atrial transport; in patients with persistent AF or after Sawtell therapy, DAY maintained efficacy while H.A. pacing showed attrition in effectiveness. DAY was better tolerated than H.A. pacing, with fewer crossovers and comparable safety to H.A. pacing. Conclusions: DAY is an important therapeutic tool in an “hybrid” strategy for management of drug‐refractory AF. It offers antiarrhythmic and hemodynamic benefits and can have therapeutic effects on symptomatic and asymptomatic paroxysmal and persistent AF. It can facilitate efficacy of other antiarrhythmic therapies in AF. Further study of its antiarrhythmic effects with hybrid drug and ablation therapies is now in progress, and long‐term use in an “hybrid” strategy has been reported in large pilot studies.

The effect of atrial pacing therapies on atrial tachyarrhythmia burden and frequency: Results of a randomized trial in patients with bradycardia and atrial tachyarrhythmias

ObjectivesThe Atrial Therapy Efficacy and Safety Trial (ATTEST) was a prospective, randomized study to evaluate preventive pacing and antitachycardia pacing (ATP) in patients with symptomatic atrial fibrillation (AF) or atrial tachycardia (AT). BackgroundThe effect of the combination of atrial prevention and termination algorithms on AT/AF burden and frequency in pacemaker patients is unknown. MethodsA DDDRP pacemaker (AT500, Medtronic Inc., Minneapolis, Minnesota) with three atrial preventive pacing algorithms and two ATP algorithms was implanted in 368 patients. Patients were randomized one-month post-implant to all prevention and ATP therapies ON or OFF and followed for three months. The OFF group had DDDR pacing at a lower programmed rate of 60 ppm. The AT/AF burden and frequency were determined from daily device counters in 324 patients treated according to protocol. ResultsIn 17,018 episodes with stored electrograms, appropriate detection was confirmed in 17,004 (99.9%). The median percentage of atrial pacing was 98% in the ON group versus 75% in the OFF group (p < 0.001). Using device-defined criteria for successful termination, ATP terminated 8,590 (54%) of 15,789 treated episodes. The median AT/AF burden during the three-month study period was 4.2 h/month ON versus 1.1 h/month OFF (p = 0.20). The median AT/AF frequency was 1.3 episodes/month ON versus 1.2 episodes/month OFF (p = 0.65). System-related, complication-free survival at four months was 90.2% (Kaplan-Meier estimate). ConclusionsThis DDDRP pacemaker is safe, has accurate AT/AF detection, and provides ATP with 54% efficacy as defined by the device. The atrial prevention and termination therapies combined did not reduce AT/AF burden or frequency in this patient population.

Controlled, randomized comparison of right atrial pacing versus biatrial pacing for prevention of atrial fibrillation after cardiac surgery

Controlled, randomized comparison of right atrial pacing versus biatrial pacing for prevention of atrial fibrillation after cardiac surgery

Suppression of atrial tachyarrhythmias by pacing.

Treatment of atrial tachyarrhythmias (ATs) remains difficult in many patients. Accordingly, new therapeutic approaches for AT suppression are evaluated. Atrial pacing may prevent ATs by modifying the electrophysiologic conditions required for sustained ATs. New pacing algorithms for prevention of AT are aimed at permanent overdrive suppression of arrhythmic activity, reduction of dispersion of atrial refractoriness produced by short-long cycles, more aggressive overdrive pacing after spontaneous sinus conversion to prevent early reinitiation of ATs, and prevention of inadequate rate decay in patients with vagally induced ATs. AT prevention may be achieved by dedicated atrial pacing sites, e.g., pacing at the insertion of Bachmann's bundle or biatrial pacing, which compensates for interatrial conduction delay. Preexciting regions of critical conduction delay, pacing at the triangle of Koch or coronary sinus os, and dual-site right atrial pacing have shown antiarrhythmic effects. Atrial preventive pacing and pharmacologic treatment may work synergistically in the concept of hybrid therapy. To prevent atrial electrical remodeling, early termination of AT seems desirable. This may be achieved by implanted devices that automatically detect ATs and provide atrial antitachycardia pacing for organized ATs. Initial studies showed that regular AT can automatically be terminated in approximately 50% of treated episodes. Pacing for prevention of AT and termination of organized AT episodes may become important steps within the concept of hybrid therapy of AT. However, their clinical efficacy and optimal patient selection remain to be evaluated in prospective, well-designed clinical trials.

The complementary role of drug, ablation and device in the electrical therapy of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia. Current therapies, including pharmacological treatment, radiofrequency ablation and implantable devices, showed significant limitation when used alone. Recently a number of combined therapies (hybrid therapy approach) were suggested. Radiofrequency ablation may improve the efficacy of drugs, pacing and automatic internal defibrillators. Antiarrhythmic drugs may play a similar role, enhancing preventive atrial pacing effectiveness as well as sinus rhythm restoration capabilities of cardioversion shocks and antitachycardia pacing. The availability of a wide range of therapeutic options suggests that the approach to the treatment of AF needs to be selected on an individual basis.

Intravenous amiodarone and off-pump coronary artery bypass graft procedures: A new role for intraoperative antiarrhythmic therapy?

Intravenous amiodarone and off-pump coronary artery bypass graft procedures: A new role for intraoperative antiarrhythmic therapy?