Objective: To assess the preclinical effects on cognitive functions of nonrheumatic atrial fibrillation (NRAF) in patients with negative history for cerebrovascular disease.
Materials and methods: The study included 37 consecutive patients with chronic (n=16, mean age 65.3+/-6.6 years) or paroxysmal (n=21, mean age 58.3+/-9.5 years) NRAF and an equal number of control subjects in sinus rhythm, who were matched for age, education and presence of hypertension. A comprehensive neuropsychological battery including tests of attention, memory, language and visuospatial skills was administered.
Results: Patients with chronic NRAF showed significantly poorer performances in tasks exploring attention and verbal memory functions, while the paroxysmal group was significantly impaired in a long-term memory task. The neuropsychological findings were confirmed excluding from both groups patients with CT evidence of cerebrovascular damage. A small subgroup of patients was also submitted to cerebral MRI.
Conclusion: Neurologically asymptomatic NRAF is related to a subclinical but significant impairment in attention and memory. These deficits could be produced by minor ischemic lesions due to microembolization, or by diffuse hypoxic damage due to hypoperfusion.