Atrial fibrillation (AF) is the most common cardiac arrhythmia with a worldwide prevalence of approximately 2% (3, 4, 5). The occurrence of the disease depends on age, the prevalence among people under 60 years old is less than 1%, among people 80 years old and older it is 7...9%. Based on prevalence indicators, there may be up to 26,000 people with KVA in Estonia (6), according to health insurance data, even more. CVD often occurs as a result of heart damage due to hypertension, ischemia or valvular pathology, but can also occur independently. CVD increases the risk of mortality and reduces the quality of life (7). CVA is accompanied by the risk of arterial thromboembolism, the most dangerous complication related to it is cerebral infarction, which occurs with a frequency of five cases per 100 patient-years. The risk of stroke increases with age. Based on data from the Health Insurance Fund, 10...19% of cerebral infarctions requiring hospitalization in Estonia are related to atrial fibrillation, and 2.8% of patients with CVA suffer from cerebral infarction annually (6). Based on epidemiological studies, CVD is found in 30% of patients with primary stroke (71). Another important complication of CVD is heart failure, which occurs due to a rapid heart rate. Heart failure decompensation occurs three times more often in patients with CVD than in the general population (8). Specialists from many disciplines come into contact with KVA. The results of a recent audit (9) revealed that management of this arrhythmia varies and evidence-based treatment options are often missed. The Estonian treatment guide helps to ensure that CVD is diagnosed on time and that patients receive sufficient information about the disease and modern treatment that matches their risk profile.