MODEL RELEASED: A man experiences the pain of a heart attack (myocardial infarction). Sudden death of part of the heart muscle is characterised in most cases by unremitting chest pain. Shortness of breath, anxiety, clammy skin, nausea and loss of consciousness may also be symptoms. In mild cases the symptoms may be absent and the attack is known as a silent infarct. Infarction is caused by deprivation of blood supply, which is usually a result of atherosclerosis in the coronary arteries (fatty deposits impeding blood flow and encouraging clot formation). Risk factors include smoking, high blood pressure, obsesity and a family history of heart disease.