Popular Cardiologist in yelahanka New Town, Bangalore • The causes of coronary symptoms The symptoms of coronary artery disease are caused by the reduction of myocardial perfusion that results from narrowing of the lumen of one or more of the coronary arteries. This narrowing is most often the result of atherosclerosis. Other much less common causes include: 1 coronary artery spasm (often in an already diseased segment of artery but sometimes as a result of the use of cocaine) 2 thrombosis (usually on an already diseased, or occasionally aneurismal, segment) 3 embolism (e.g. from an infected aortic valve) 4 congenital coronary abnormality 5 vasculitis. Numerous other cardiac symptoms and problems can be the eventual result of atheromatous coronary disease. These include myocardial infarction cardiac failure cardiac arrhythmias and some cardiac valve problems. Risk factor mechanisms of action Atherosclerosis is thought to result primarily from a disturbance of the vascular endothelium. The final common pathway for the effects of endothelial dysfunction is largely through abnormalities of nitric oxide (NO) production. This chemical, released by a healthy endothelium, is a potent vasodilator and has anti-inflammatory and other favourable actions on the arteries. Causes of this disturbance can be: mechanical (hypertension) chemical (oxidised lipids, components of cigarette smoke, hyperinsulinaemia) or due to immunological injury. The damaged endothelium attracts inflammatory mediators, platelets and circulating lipids and promotes fibroblast and smooth muscle proliferation. This results in the formation of a plaque, which may narrow the arterial lumen. Plaques can remain stable (or sometimes regress), enlarge, rupture or erode (more common in diabetics). Most acute ischaemic events (acute coronary syndromes or acute myocardial infarctions) are thought to be the result of further luminal narrowing caused by the formation of partly or fully occlusive thrombus on a ruptured or eroded plaque. Coronary risk factors may therefore operate because they are atherogenic or thrombogenic.