This is a randomized open controlled single centre study that involves 60 patients (men and women) over the age of 50 years with longstanding persistent AF of more than one year duration and in the absence of other severe cardiopulmonary disease. One of the participating investigators informs the patient, both verbally and in writing, about the study and what participation in the study involves. The patient will be given time to ask questions and to consider study participation and can be enrolled in the study after signing and dating written Informed Consent. Study duration per patient is 12 months.