Atrial rhythm after atrioventricular junctional ablation

Ablate and pace revisited: long term survival and predictors of permanent atrial fibrillation

OBJECTIVE

To assess long term mortality and identify factors associated with the development of permanent atrial fibrillation after atrioventricular (AV) node ablation for drug refractory paroxysmal atrial fibrillation.

DESIGN

Retrospective cohort study.

SETTING

UK tertiary centre teaching hospital.

PATIENTS

Patients admitted to the University Hospital Birmingham between January 1995 and December 2000.

INTERVENTIONS

AV node ablation and dual chamber mode switching pacing.

MAIN OUTCOME MEASURES

Long term mortality and predictors of permanent atrial fibrillation, assessed through Kaplan-Meier curves and logistic regression.

RESULTS

114 patients (1995-2000) were included: age (mean (SD)), 65 (9) years; 55 (48%) male; left atrial diameter 4 (1) cm; left ventricular end diastolic diameter 5 (1) cm; ejection fraction 54 (17)%. Indications for AV node ablation were paroxysmal atrial fibrillation in 95 (83%) and paroxysmal atrial fibrillation/flutter in 19 (17%). The survival curve showed a low overall mortality after 72 months (10.5%). Fifty two per cent of patients progressed to permanent atrial fibrillation within 72 months. There was no difference in progression to permanency between paroxysmal atrial fibrillation and paroxysmal atrial fibrillation/flutter (log rank 0.06, p = 0.8). Logistic regression did not show any association between the variables collected and the development of permanent atrial fibrillation, although age over 80 years showed a trend (p = 0.07).

CONCLUSIONS

Ablate and pace is associated with a low overall mortality. No predictors of permanent atrial fibrillation were identified, but 48% of patients were still in sinus rhythm at 72 months. These results support the use of dual chamber pacing for paroxysmal atrial fibrillation patients after ablate and pace.

No incremental benefit of multisite atrial pacing compared with right atrial pacing in patients with drug refractory paroxysmal atrial fibrillation

OBJECTIVE

To evaluate the incremental antifibrillatory effect of multisite atrial pacing compared with right atrial pacing in patients with drug refractory paroxysmal atrial fibrillation paced for arrhythmia prevention alone.

METHODS

In 20 of these patients (mean (SD) age 64 (8) years; 14 female, six male), a single blinded randomised crossover study was performed to investigate the incremental benefit of one month of multisite atrial pacing compared with one month of right atrial pacing. Outcomes included the number of episodes of paroxysmal atrial fibrillation, their total duration obtained from pacemaker Holter memory, and quality of life using a cardiac specific questionnaire (the modified Karolinska questionnaire).

RESULTS

Comparing right atrial with multisite atrial pacing, there was no significant change in either the number of paroxysmal atrial fibrillation episodes (mean (SD): right atrial pacing 77 (98) episodes v multisite pacing 52 (78) episodes, NS) or their total duration (right atrial, 4.8 (5.4) days v multisite, 6.3 (9.8) days, NS). Quality of life scores compared with baseline status were equally improved by either pacing strategy (mean percentage improvement: right atrial, 38%, p = 0.003; multisite, 44%, p = 0.003). There was no significant difference in life scores comparing the two pacing modes.

CONCLUSIONS

Multisite atrial pacing has no incremental antiarrhythmic effect compared with right atrial pacing in patients paced for drug refractory paroxysmal atrial fibrillation. Quality of life is equally improved with either pacing strategy, with no differences between them.

Ablate and pace for drug refractory paroxysmal atrial fibrillation. Is ablation necessary?

BACKGROUND

Atrio-ventricular junctional ablation with pacemaker insertion has been shown to improve quality of life in patients with drug refractory paroxysmal atrial fibrillation. It is unknown whether this improvement is secondary to the ablation procedure or to the pacemaker mode utilised. To investigate this we reviewed our experience of implanting a dual chamber rate responsive pacemaker with mode switching (DDDR/MS) alone on quality of life in this patient group.

METHODS AND RESULTS

Over a 1-year period, 19 patients (mean age 62+/-9 years, 13 female) with drug refractory paroxysmal atrial fibrillation (mean duration of symptoms 8.7+/-7 years, failed 3.1+/-0.9 anti-arrhythmic drugs, amiodarone in 15) were recruited. Quality of life was assessed at baseline and after 1 month using a cardiac specific questionnaire, the modified Karolinska questionnaire. The mean score for all patients significantly improved by 39% at follow up (baseline 59+/-24, 1 month 36+/-24, P=0.001). Individually 15 patients (79%) had an improvement in their score, whilst for 13 patients (68%) their symptoms were sufficiently improved after pacing that ablation was not required. The benefit was maintained to a mean follow up of 12+/-5 months (score 31+/-20, P<0.001). Six patients remained symptomatic after pacing and requested further treatment. Benefit was unrelated to symptoms at baseline or the number and total duration of paroxysmal atrial fibrillation episodes recorded on pacemaker Holter.

CONCLUSIONS

Patients with drug refractory paroxysmal atrial fibrillation, DDDR/MS pacing alone can improve quality of life without concurrent atrio-ventricular junctional ablation in a significant proportion of patients.

Randomized crossover comparison of DDDR versus VDD pacing after atrioventricular junction ablation for prevention of atrial fibrillation. The atrial pacing peri-ablation for paroxysmal atrial fibrillation (PA (3)) study investigators

BACKGROUND

Some clinical data suggest that atrial-based pacing prevents paroxysmal atrial fibrillation (AF). This study tested the hypothesis that DDDR pacing compared with VDD pacing prevents AF after atrioventricular (AV) junction ablation.

METHODS AND RESULTS

Patients were randomized to DDDR pacing (n=33) or to VDD pacing (n=34) after AV junction ablation and followed every 2 months for 6 months. Patients then crossed over to the alternate pacing mode and were followed for an additional 6 months. Primary analysis included the time to first recurrence of sustained AF (duration >5 minutes), total AF burden, and the development of permanent AF. The time to first episode of AF was similar in the DDDR group (0.37 days, 95% CI 0.1 to 1.3 days) and the VDD pacing group (0.5 days, 95% CI 0.2 to 1.7 days, P=NS). AF burden increased over time in both groups (P<0.01). At the 6-month follow-up, AF burden was 6.93 h/d (95% CI 4. 37 to 10.96 h/d) in the DDDR group and 6.30 h/d (95% CI 3.99 to 9.94 h/d) in the VDD group (P=NS). Twelve (35%) patients in the DDDR group and 11 (32%) patients in the VDD group had permanent AF within 6 months of ablation. Within 1 year of follow-up, 43% of patients had permanent AF.

CONCLUSIONS

DDDR pacing compared with VDD pacing does not prevent paroxysmal AF over the long term in patients in the absence of antiarrhythmic drug therapy after total AV junction ablation. Many patients have permanent AF within the first year after ablation.

Survival of DDD pacing mode after atrioventricular junction ablation and pacing for refractory atrial fibrillation

BACKGROUND

Patients with recurrent forms of atrial fibrillation may receive dual-chamber pacemakers after atrioventricular junction ablation for refractory symptoms. These patients are at risk for chronic atrial fibrillation, which would negate the benefits of dual-chamber pacing. The purpose of this study was to examine the survival of dual-chamber pacing modes in patients undergoing ablate and pace therapy.

METHODS AND RESULTS

One hundred fifty-six patients underwent ablate and pace therapy for medically refractory chronic (70 patients) or recurrent (86 patients) atrial fibrillation. Seventy-eight percent of patients had structural heart disease. The mean age was 66 +/- 11 years, with an average ejection fraction of 48% +/- 18%. The choice of pacing mode and programming were at the discretion of the investigators. At implantation, 91 patients (58%) were programmed to VVI mode, 47 (30%) were programmed to DDD mode, and 18 (12%) were programmed to DDI mode. After 1 year of follow-up, 10 DDD patients were reprogrammed to VVI mode (7 patients) or DDI mode (3 patients), most frequently for chronic atrial fibrillation (7 patients). Two patients with DDI mode were reprogrammed to VVI and DDD modes (1 patient each). Survival of the DDD mode was 76% at 1 year by Kaplan-Meier analysis. Reprogramming from DDD mode was not associated with patient age, left ventricular ejection fraction, discontinuation of antiarrhythmic drugs, or the duration of atrial fibrillation symptoms before ablation.

CONCLUSIONS

Seventy-six percent of patients with recurrent atrial fibrillation who are initially programmed to DDD mode remain in DDD mode 1 year after ablation and pacing therapy. The modest rate of progression to chronic atrial fibrillation supports the use of dual-chamber pacing in this setting.

Determinants of development of permanent atrial fibrillation and its treatment

We evaluated the rate of progression of permanent atrial fibrillation (AF) and identified clinical factors that predict this event in 63 consecutive patients who had undergone AV junctional ablation and DDDR pacemaker implantation for drug-refractory paroxysmal atrial fibrillation/ flutter. Immediately after ablation, anti-arrhythmic drugs were discontinued in all cases. Permanent AF was considered to have developed if AF was present on two consecutive 6-monthly examinations with no interim documented sinus rhythm. During a mean follow-up of 23 +/- 16 months, 22 (35%) of the 63 patients developed permanent AF. The actuarial estimate of progression of permanent AF was 22%, 40% and 56%, respectively, 1, 2 and 3 years after ablation. Age and underlying heart disease were independent predictors of progression of permanent AF. Only one (6%) of 16 patients with idiopathic AF had permanent AF (low risk group). Among the 47 patients with structural heart disease, permanent AF developed in 18 (62%) of the 29 who were aged >75 years or had >12 arrhythmic episodes per year and a symptom duration >4 years (high risk group), but only in three (17%) of the remaining 18 patients who did not (intermediate risk group). In conclusion, during a 3-year follow-up period, about half of the patients with a history of drug-refractory paroxysmal AF did not develop permanent AF after AV junctional ablation and dual-chamber pacemaker implantation, even in the absence of anti-arrhythmic drug therapy. Moreover, subgroups of patients whose risk of permanent AF progression differed were identified on the basis of simple baseline clinical variables. The results of this study form the necessary background for the correct management of patients after AV junction ablation and for the planning of future trials in this field.

Chronic atrial fibrillation in patients with paroxysmal atrial fibrillation, atrioventricular node ablation and pacemakers: determinants and treatment

AIMS

This study examined the factors associated with the development of chronic (or permanent) atrial fibrillation (AF) in patients who had undergone atrioventricular (AV) node ablation with permanent pacing because of paroxysmal AF.

METHODS

A retrospective review of case notes of all 65 consecutive patients identified as having had paroxysmal atrial arrhythmias, AV node ablation and permanent pacemaker implantation was performed. Atrial rhythm was established from all pacing records and from the surface ECG. Treatment with anti-arrhythmic drugs and with warfarin was recorded. A multivariate analysis was undertaken, using atrial rhythm on final ECG and chronic AF as outcome measures.

RESULTS

During a mean follow-up of 30 months, 42% of patients with paroxysmal AF had developed chronic AF. Multivariate analysis showed that increasing age, history of electrical cardioversion and VVI pacing all contributed to the development of chronic AF. 25/62 patients were taking warfarin, and four had had strokes (2.5%/year).

CONCLUSION

The majority of patients with paroxysmal atrial arrhythmias treated with AV node ablation and pacing develop chronic AF eventually. Stroke remains a risk, particularly in those who develop chronic AF.

Report of a study group on ablate and pace therapy for paroxysmal atrial fibrillation. Barcelona Discussion Group. Working Group on Arrhythmias of the European Society of Cardiology

Atrioventricular junctional (AVJ) catheter ablation followed by pacemaker implantation is now widely accepted for patients affected by paroxysmal atrial fibrillation (PAF) not controlled by antiarrhythmic drugs. However, few data exist on its indications, optimal methodology and complications. Therefore a study group examined current practice in Europe and North America, using a questionnaire, followed by a Study Group Meeting to discuss the results. Based upon this, class I, class II and class III indications were proposed. Class I indications (for which general agreement existed) include drug-refractory PAF, correlating with important symptoms, the bradycardia tachycardia syndrome already treated with a pacemaker, and continued PAF. Large differences exist in the current methodology, but consensus was reached on the technical approaches of right and left-sided AVJ ablation, and on the timing of pacemaker implant in relation to ablation. No complete agreement was reached on technical features such as catheter choice and heparin use. The recommended pacing mode was DDDR with mode switching.

VDDR pacing after His-bundle ablation for paroxysmal atrial fibrillation: a pilot study

His-bundle ablation followed by pacemaker implantation is today a widely accepted therapeutic choice when drug refractoriness of symptomatic AF is evident. The selection of pacing mode in patients suffering from paroxysmal AF is still controversial. Preservation of AV synchrony is an attractive option in patients with paroxysmal AF who undergo His-bundle ablation. The purpose of this study was to examine prospectively the contribution of VDDR pacing for preservation of AV synchrony. After His-bundle ablation a VDDR pacing system was implanted in 17 patients with paroxysmal AF, and all antiarrhythmic drugs were withdrawn. The endpoint of the study was defined as the onset of chronic AF. To document the onset of chronic AF 48-hour Holter recordings were made every 6-8 weeks. After a mean followup of 18.2 (range 14-21) months, VDDR pacing is still operative in 13 patients (77%). Four patients developed chronic AF after a mean follow-up of 6 months. Of several baseline characteristics, only the intraatrial P wave at implantation was significantly smaller in patients developing chronic AF than in patients in whom the VDDR mode is still operative. This pilot study suggests that VDDR pacing is an attractive pacing method for patients with paroxysmal AF after His-bundle ablation. A low intraatrial P wave electrogram at implant was associated with a higher risk for the development of chronic AF.

Predictors of atrial rhythm after atrioventricular node ablation for the treatment of paroxysmal atrial arrhythmias

OBJECTIVE

To assess the natural history of the atrial rhythm of patients with paroxysmal atrial arrhythmias undergoing atrioventricular node ablation and permanent pacemaker implantation.

DESIGN AND SETTING

A retrospective cohort study of consecutive patients identified from the pacemaker database and electrophysiology records of a tertiary referral hospital.

PATIENTS

62 consecutive patients with paroxysmal atrial arrhythmias undergoing atrioventricular node ablation and permanent pacemaker implantation between 1988 and July 1996.

MAIN OUTCOME MEASURES

(1) Atrial rhythm on final follow up ECG, classified as either ordered (sinus rhythm or atrial pacing) or disordered (atrial fibrillation, atrial flutter or atrial tachycardia). (2) Chronic atrial fibrillation, defined as a disordered rhythm on two consecutive ECGs (or throughout a 24 hour Holter recording) with no ordered rhythm subsequently documented.

RESULTS

Survival analysis showed that 75% of patients progressed to chronic atrial fibrillation by 2584 days (86 months). On multiple logistic regression analysis a history of electrical cardioversion, increasing patient age, and VVI pacing were associated with the development of chronic atrial fibrillation. A history of electrical cardioversion and increasing patient age were associated with a disordered atrial rhythm on the final follow up ECG.

CONCLUSIONS

Patients with paroxysmal atrial arrhythmias are at high risk of developing chronic atrial fibrillation. A history of direct current cardioversion.

Progression of permanent atrial fibrillation after atrioventricular junction ablation and dual-chamber pacemaker implantation in patients with paroxysmal atrial tachyarrhythmias

Among 63 patients affected by symptomatic drug refractory paroxysmal atrial fibrillation who had undergone atrioventricular junction ablation and dual-chamber pacemaker implantation, the actuarial estimate of progression of permanent atrial fibrillation was 22%, 40%, and 56% respectively, 1, 2, and 3 years after ablation. A stratification of the risk of development of permanent atrial fibrillation was obtained on the basis of several clinical variables.