Echo scan

Clots originating in the heart and travelling in the bloodstream, up to the brain, are an important preventable cause of strokes. An abnormal heart rhythm, atrial fibrillationA common abnormal heart rhythm causing a rapid, irregular pulse and failure of the upper chambers of the heart (atria) to pump properly. Abbreviated to AF., can predispose people to this condition. Clots that have formed within one of the chambers of the heart can be detected by ultrasound of the heart - a technique called echocardiographyThe use of ultrasound to examine the heart as it is pumping. .

Another condition that echocardiographyThe use of ultrasound to examine the heart as it is pumping. may pick up is a 'hole in the heart' - a foramen ovaleThe opening between the two upper chambers (atria) of the heart of the fetus, which normally closes at birth. The term 'foramen ovale' may also be used to describe the large hole at the base of the skull. - which may predispose to clot formation and allow clots to pass through to the left side of the heart, from where they may travel to the brain.[1]

Two methods of echocardiographyThe use of ultrasound to examine the heart as it is pumping. are available: transthoracicOver or through the chest (thorax). echocardiographyThe use of ultrasound to examine the heart as it is pumping. , where the ultrasound probe is placed over the surface of the chest, or transoesophagealOver or through the gullet (oesophagus). echocardiographyThe use of ultrasound to examine the heart as it is pumping. , in which the probe is passed down the gullet, or oesophagusThe gullet, the part of the gastrointestinal system that extends down from the mouth cavity to the stomach.. Transoesophageal echocardiographyThe use of ultrasound to examine the heart as it is pumping. is more sensitive in picking up any problems.[1]

References: 
  1. Haosheng Yu E, Lungu C, Kanner RM et al. The use of diagnostic tests in patients with acuteHas a sudden onset. ischemic stroke. Journal of Stroke and Cerebrovascular Diseases 2009; 18: 178-84.