AFIB may cause cognitive decline via multiple mechanisms:
- Stroke
- Multiinfarct dementia due to microinfarcts
- Microbleeds as a result of anticoagulants
- Cerebral hypoperfusion – decreased blood flow to the brain
- Decline in brain volume
- Beta blockers ??may contribute
- Catheter ablation for AFIB contributes to micro infarcts (ACE – asymptomatic cerebral emboli)
- AFIB may be a marker for other inflammatory processes including diet that also lead to dementia
Alonso et. al. have a good review article regarding AFIB and dementia.
Thacker et.al. studied 5,888 patients for 7 years and found that cognitive decline was accelerated in presence of AFIB.
Marzona et.al. found similar results in 31,506 patients – increase in risk of cognitive decline, dementia, loss of independence in activities of daily living and risk of admission to nursing homes.
The ARIC study found that AFIB is strongly correlated with dementia. The Rotterdam study found similar results in Europe.
Finally, there is an expert consensus statement by Heart Rhythm Society released in 2018 on arrhythmias and cognitive decline. Read it!
The best way to not get AFIB related dementia is to prevent AFIB in the first place.