Atrial fibrillation and cognitive impairment: prevalence and pathophysiological mechanisms for the relationship (Part 1)

Atrial fibrillation (AF) is a common rhythm disorder, especially in the elderly and senile people, and its incidence is expected to be only increasing. Another urgent problem of modern health care is cognitive impairment (CI) and dementia, which are also highly prevalent. Studies show that AF and CI are closely interrelated: patients with this heart rhythm disturbance are at increased risk for both CI in general and dementia in particular, their cognitive decline progresses faster regardless of whether AF is paroxysmal or permanent. The association between CI and AF is largely due to the commonality of risk factors, the main of which are considered to be elevated blood pressure, atherosclerotic vascular damage, diabetes mellitus, and age. To date, the specific pathogenetic mechanisms of CI development in AF have been described, indicating that both vascular and neurodegenerative changes are implicated in cognitive decline in the presence of cardiac arrhythmias in question. These changes include a history of stroke, the well-known risk factor for the cardioembolic type of which is AF; microembolism and microhemorrhage; predisposition to prothrombotic states; cerebral hypoperfusion and a proinflammatory shift associated with this arrhythmia. In addition, a potential adverse effect on CI can be produced by the use of antagonists of vitamin K, since the latter is an important trophic factor necessary for normal cognitive functioning.