Left atrium dilatation and multiple vascular territory strokes.

Area of Science:

• Cardiology
• Neurology
• Radiology

Background:

• Atrial fibrillation (AF) is a significant cause of ischemic stroke, often associated with stroke recurrence and multi-vessel territory infarcts.
• Undiagnosed paroxysmal AF is a potential cause for many cryptogenic strokes.
• Left atrial (LA) dilatation is a known risk factor for AF.

Purpose of the Study:

• To investigate the association between moderate or severe LA dilatation and multiple vascular territory infarcts on MRI.
• To assess this association in patients presenting with acute ischemic stroke (AIS) or transient ischemic attack (TIA) without a known history of AF.

Main Methods:

• Retrospective analysis of 356 patients diagnosed with AIS or TIA between 2006 and 2011.
• Inclusion criteria: transthoracic echocardiography and brain MRI.
• Exclusion criteria: known AF or de novo AF diagnosed within 3 months of the event. The primary outcome was acute multi-vessel territory infarcts on MRI.

Main Results:

• Patients with moderate to severe LA dilatation (mean LA diameter 49 mm) showed a significantly higher incidence of multiple vascular territory infarcts compared to those with normal or mildly dilated LA (mean LA diameter 37 mm).
• The odds ratio for multiple infarcts in the LA dilatation group was 3.89 (p=0.0014).
• 20% of patients with LA dilatation experienced multiple infarcts versus 6% in the control group.

Conclusions:

• Moderate to severe LA dilatation is associated with acute non-lacunar, multiple vascular territory infarcts on MRI in patients with AIS or TIA who do not have known AF.
• This suggests LA dilatation may serve as a marker for increased stroke risk in this population.
• Further research is needed to determine if anticoagulation therapy could benefit these patients.