  Background Atrial fibrillation is often missed by traditional intermittent
electrocardiogram monitoring after ischemic stroke due to its paroxysmal and
asymptomatic nature. The knowledge of the unique characteristics of the
population with atrial fibrillation detected after stroke (AFDAS) enables more
ischemic stroke patients to benefit from more aggressive anticoagulation
therapy and AF management. Method This is an observational, retrospective, MRI
imaging-based single-center study. Patients with AFDAS were matched in 1:3
ratio with patients without AF (NoAF)and patients with known AF before
stroke(KAF) in PSM model based on age, gender, and time from stroke onset to
admission. Multivariate logistic models were used to test the association of
MRI-based stroke lesion distribution, other clinical parameters and AF. A
backward stepwise elimination regression was conducted to identify the most
important variables. Results Compared to the NoAF group(n=103), the patients
with AFDAS (n=42) had more cortical involvement(p=0.016), as well as
temporal(p<0.001) and insular lobes(p=0.018) infraction. After performing a
backward stepwise elimination model in regression analysis, the temporal lobe
infraction(OR 0.274, 95%CI 0.090-0.838, p=0.023) remained independently
associated with the detection of AF. Compared to the KAF group(n=89), LAD(OR
1.113, 95%CI 1.022-1.211, p=0.014), Number of lobes infarction(p=0.012),
3-lobes involvement(OR 0.177, 95%CI 0.056-0.559, p=0.003), and left hemisphere
lobe involvement(OR 5.966, 95%CI 2.273-15.817, p<0.001)) were independently
associated with AFDAS and KAF. Conclusions Ischemic stroke patients with AF
detected after stroke present more temporal lobe infraction and cortical
involvement. These lesion distribution characteristics with clinical
characteristics together may help in stratifying patients with long-term
cardiac monitoring after stroke.
