b'ChapterHeart AttackHeart attack is usually the result of cardiovascular disease (disease of the heart and blood vessels) and is the leading cause of death for adults in Australia.Heart attack is difficult to diagnose because chest pain or discomfort that seems like a heart attack may in fact be something else. The problem may be indigestion, muscle strain or spasm, gall bladder disorder, hernia, stress or lung condition.The heart needs high levels of oxygen in order to keep functioning efficiently. Over a period of many years, however there may a build up of fatty deposits (particularly cholesterol) on the inside of the blood vessels (coronary arteries) that provide oxygen to the heart muscle (myocardium). This restricts blood flow and reduces the amount of oxygen reaching the heart muscle. Blood flow to the heart may slow to such an extent that the blood becomes thickened, which may then cause clotting and lead to a complete blockage. If the myocardium is deprived of oxygen, it becomes damaged and if enough tissue is affected, the heart will not pump effectively. A heart attack is sometimes called acute myocardial infarction. A heart attack can interrupt the hearts electrical rhythm and the hearts ability to pump blood. Instead of beating normally, the rhythm can become chaotic (ventricular fibrillation), leading to ineffective heart failure and cardiac arrest. Cardiac arrest can follow on from the symptoms of a heart attack and may strike suddenly.Although heart attack may seem to strike suddenly, our lifestyle has proven to be gradually endangering our heart. Medical research has identified numerous risk factors which increase the chances of a person developing heart disease. Some risk factors cannot be changed, however many can be controlled.Risk Factors for Heart DiseaseSmoking.Diets high in fat.High serum cholesterol.High blood pressure. Obesity and lack of routine exercise.Family history.Stress.Diabetes.Sedentary lifestyle.Heart attack is a time criticalmedical emergency.194 Medical Emergencies'