Incidence of asymptomatic atrial fibrillation in patients at high risk for stroke and associated factors

ABSTRACT INCIDENCE OF ASYMPTOMATIC ATRIAL FIBRILLATION IN PATIENTS AT HIGH RISK FOR STROKE AND ASSOCIATED FACTORS Atrial fibrillation is the most common permanent arrhythmia in the society. Atrial fibrillation increases the risk of stroke 5-7 times. Atrial fibrillation has become a major public health problem because of this thromboembolic risk. Asymptomatic episodes of atrial fibrillation are more common than symptomatic ones in general population. The risk of stroke in patients with asymptomatic atrial fibrillation is similar to that of patients with symptomatic atrial fibrillation. In the present study, we aimed to search the incidence of asymptomatic atrial fibrillation in patients at high risk for stroke but no history of atrial fibrillation and determine the factors associated with asymptomatic atrial fibrillation. One hundred fourty patients, evaluated in our cardiology department, with no history of atrial fibrillation or symptoms which might suggest atrial fibrillation and have risk factors for stroke included in our study. Patients' demographic, clinical and echocardiographic data which might be associated with atrial fibrillation were recorded. These patients were then followed by 24-hour ambulatory electrocardiographic monitoring (Holter monitoring). Patients who had with episodes of asymptomatic atrial fibrillation over 5 seconds and 30 seconds were analyzed for factors associated with atrial fibrillation. The mean age of patients was 74.5±7.16 (50% female). The frequency of asymptomatic atrial fibrillation lasting over 5 seconds was 17.9%, and lasting over 30 seconds was 5.0%. Age and chronic obstructive pulmonary disease were found to be independent risk factors for atrial fibrillation lasting at least 5 seconds (p=0.001 ve p=0.002). Age and maximum heart rate during Holter monitoring were found to be independent risk factors for atrial fibrillation lasting at least 30 seconds (p=0.028 ve p=0.044). In conclusion, there is a high incidence of asymptomatic atrial fibrillation in patients at high risk for stroke. Older age, chronic obstructive pulmonary and maximum heart rate during Holter monitoring may be associated with asymptomatic atrial fibrillation. Key words: Atrial fibrillation, stroke, age, chronic obstructive pulmonary disease, Holter monitoring