Patent foramen ovale and cryptogenic stroke

Stroke is common, affecting approximately 150 000 people every year in the UK, of which 10 000 people are of working age. While most strokes occur as a result of atherosclerosis and other major risk factors, there are a minority of patients in whom rare causes of stroke are present. Of these, patent foramen ovale (PFO) is becoming increasingly important, especially in younger patients presenting with embolic stroke, who have no vascular risk factors, are in normal sinus rhythm and do not have valvular heart disease.