Atrial fibrillation - practical issues

Abstract

Covert atrial fibrillation (AF) is the most common cause of cryptogenic stroke or embolic stroke of undetermined source (ESUS). Evidence has suggested that longer monitoring of heart rhythm can detect AF more frequently. Many implanted or wearable devices have been developed for long heart rhythm monitoring to detect covert AF. Guidelines recommend to monitor heart rhythm for 30 days in patients with cryptogenic stroke within 6 months after the onset. However, there is no consensus how long AF can cause stroke. Predictors for covert AF in stroke patients have been reported by us and other investigators. Guidelines recommend antiplatelet therapy as the first line of treatment for the prevention of recurrent stroke in patients with cryptogenic stroke or ESUS. However, rate of stroke recurrence is still high even with antiplatelet therapy in these patients. Randomized controlled trials of direct oral anticoagulants versus aspirin are ongoing to compare the efficacy and safety in ESUS patients. AF is also an important risk factor for cognitive impairment and dementia. We reported that deep small infarcts and white matter lesions, which are imaging markers for vascular dementia, are common and correlated with CHADS2 score in AF patients. Recently, cortical microinfarction, which can be a new imaging marker for cognitive impairment, has also been reported to be common in AF patients. Cognitive impairment is likely to occur and progress earlier in AF patients even without cerebrovascular disease. Possible mechanisms of cognitive impairment in AF patients are reviewed.