The current evidences indicate that ~30% patients with sick sinus syndrome(SSS) would develop persistent atrial fibrillation (AF) after a long term pacing therapy. However, the accurate influence of antiarrhythmic drugs on the AF is still not well defined. The purpose of the study is to assess the therapeutic effects of various antiarrhythmic drugs (Amiodarone, Sotalol and Propafenone) on the long term management of AF in SSS patients with AF, including the reduced AF burden (duration and episodes) and persistent AF free survival rate. All patients will be followed up for 12 months.

Inclusion Criteria:

• at least 18 years old

• sick sinus syndrome with pacemaker Class I or Class IIa indication

• has a pacemaker which can provide the daily AF burden monitor record for at least 28 days

• has at AF record in the past 6 months, the valid AF record includes any of

  1. at least one 30 seconds AF holter record
  2. at least one 15 seconds 12-ECG record
  3. at least 5 minutes long AF episodes record from pacemakers

• able and willing to give informed consent

Exclusion Criteria:

• will have cardiac surgery in the next 6 month or in the waiting list of heart transplantation
• NYHA Class III or IV
• LVEF <50%
• Reversible AF, such as AF caused by hyperthyroidism or severe postoperative atrial fibrillation
• Persistence AF
• Expected life expectancy less than 1 year
• Planned to be pregnant or be in the feeding period in the next year
• Non-stable, decompensated heart failure
• Allergy to Amiodarone, Propafenone or Sotalol
• Cancer
• Clear liver damage ( ALT and/or AST > 2*normal limit)
• Patients with cardiogenic shock history
• Be in the treatment of Amiodarone for more than 3 months or less than 3 months with Amiodarone wash out period less than 30 days
• Coronary artery disease (CHD), cardiomyopathy, severe valvular heart disease, severe obstructive pulmonary disease (COPD), long QT syndrome