Investigations

• a patent foramen ovale ^a
• an atrial septal aneurysm ^a

Why?

• 40% of patients under 55 with an ischaemic stroke have a patent foramen ovale (95% CI: 28% to 52%) ^c
• 12% of patients with a combination of a patent foramen ovale and an atrial septal aneurysm have a recurrent stroke within a mean of 3 years (95% CI: 2.9% to 21%).(Hazard ratio for recurrent stroke: 4.17; 95% CI: 1.47 to 11.8). ^a
• A patent foramen ovale or an atrial septal aneurysm alone does not clearly increase the risk of recurrent stroke. ^a