Heart disease treatment. Animation showing a coronary artery that has become blocked due to atherosclerosis being treated with the insertion of a stent. Atherosclerosis is a thickening of the artery walls due to a build up of fatty plaques (yellow). This can cause a reduction in blood flow (ischaemia) to the surrounding tissue and lead to a myocardial infarction (heart attack). A balloon catheter (brown) and stent (blue) are inserted into the affected artery and the balloon is inflated to open the artery and restore normal blood flow. HD supplied with alpha, or for a flat version on a black background, see clip K003 3647.