Follow a representative sample of Latin American patients diagnosed with atrial fibrillation to set data on demographic characteristics, documenting antithrombotic therapy, describe the INR control level of VKA users, discontinuation rates and clinical outcomes, such as stroke, hemorrhage and death

Patients will be followed 6 months and 1 year after the baseline visit and will be collected data of antithrombotic therapy, laboratory data, discontinuation rates of antithrombotic therapy and clinical outcomes.

Inclusion Criteria:

• Age > 18 years-old that signed informed consent;
• Atrial Fibrillation or Atrial Flutter at the time of inclusion documented in source document;
• If the patient is not in atrial fibrillation or Atrial Flutter rhythm, s/he should have 2 electrographic records, at least 15 days apart between them, with one of them being performed within the last 6 months before enrollment (AF may be documented by 12-lead ECG, Holter monitor-24h);

Exclusion Criteria:

• Patients who did not agree to participate.
• Patients without possibility of monitoring for one year.

Patient with Atrial Fibrilation or Atrial Flutter