The present prospective cohort study (not randomized) analyses the value of screening and treatment of SAHS in the management of patients with AF refractory to antiarrhythmics drugs, potentially candidates for ablation. Patients at low risk of suffering from SAHS will follow conventional management of their AF, according to the usual criteria of the Arrhythmia Unit. Patients with high or intermediate risk of SAHS, will undergo respiratory polygraphy. If the result is positive, they will be treated as standard for this syndrome and their heart rate will be monitored for 3 months. After this, the patient's arrhythmic load will be reevaluated differentiating patients into two groups, those that must be ablated from those that have improved their condition and the clinical criteria is no longer ablation but follow-up.