Prevention of Atrial Arrhythmia in Patients Without Atrioventricular (AV) Conduction Disease

• A pacemaker indication for sinus node dysfunction and/or brady-tachy syndrome OR already implanted for less than three months for the mentioned reasons and supplied with a symphony 2550 DR at time of inclusion AND
• A PR interval \<250ms AND
• Documented atrial arrhythmia in the past year
• Medication for anti-arrhythmic must be stable for at least one month (2 months for amiodarone) prior to enrollment
• Patients must have less than two known cardioversions within the last year
• Patient has signed a consent form after having received the appropriate information

Exclusion Criteria:

• Need a replacement pacemaker device
• Have an unknown PR interval
• Known AV block ≥ 250 ms PR interval
• Minor and/or pregnant woman
• Patients enrolled in other clinical trials
• Patients with sustained ventricular arrhythmia
• Patients with severe coronary artery disease (at the discretion of the investigator)
• Patients with advanced cardiomyopathy (at the discretion of the investigator)
• Patients who have sustained a myocardial infarction or undergone cardiac surgery within the past 30 days
• Patients with unstable angina pectoris
• Patients whose life expectancy is less than 1 year
• Patients who are unlikely to return for required follow-up visits
• Patients who present with permanent atrial arrhythmia or those who usually require cardioversion to terminate such arrhythmia and/or
• Patients whose physician plans to add or change medical treatment because of AA episodes during the follow-up period.
• Patient unable to understand the purpose of the study or refusing to cooperate