A 76-year-old male consulted a therapist about slow discharge of urine with a small jet. The patient reported no cardiac problems. Examination revealed atrial fibrillation with a heart rate of 72/min and without pulse deficit. There are no signs of heart failure. ECG confirms the presence of atrial fibrillation. From history we know that the arrhythmia was detected three years ago. What tactics for the treatment of atrial fibrillation in the patient should be chosen?