This study is investigating a potential link between a novel measurement made on cardiac ultrasound and the risk of ischemic stroke in patients with a normal heart rhythm. The novel measurement is called left atrial strain. It uses speckle tracking echocardiography to measure the muscle function of the left atrium, one of the cardiac chambers. Investigators investigated whether patients with lower function of this chamber are at a higher risk of developing stroke from blood clots traveling to the brain. It is already known that patients with an irregular heart rhythm known as atrial fibrillation are at higher risk of these types of strokes. Investigators wanted to determine if there is a similar association in patients with normal heart rhythm but low left atrial strain.

Inclusion Criteria:

• Emergency department presentation with FAST positive symptoms
• Neuroimaging performed as part of stroke workup
• Echocardiogram performed during index admission

Exclusion Criteria:

• Any history of atrial fibrillation prior or during admission
• Age below 18 years of age
• No echocardiogram or echocardiogram images not of sufficient quality to perform left atrial strain analysis
• At least moderate mitral regurgitation
• ASD or PFO

Patients presenting to the emergency department with FAST positive symptoms suspicious for an acute stroke.

Echo measurements: Left atrial strain measurements, left ventricular ejection fraction, interventricular septal thickness, E/e' Demographics: Age, gender, hypertension status, smoking status, diabetes status, dyslipidaemia status,