Disorder of the coronary arteries that leads to malfunction of the heart. Atherosclerosis is the most important of these, involving thickening of the walls of the arteries by deposits of calcium and fat, reducing the internal diameter and finally closing the vessel completely and starving the heart muscle of oxygen. Narrowing of the coronary arteries causes angina pectoris, and closure of these arteries causes coronary infarction. High blood pressure creates ideal conditions for atherosclerosis, but high fat and chloresterol content in the blood, and smoking, are also important factors. Disorders of the cardiac valves are quite common, and result from rheumatic fever or endocarditis. Disorders of the heart muscles are rare, and often not susceptible to treatment. Aneurysm is a widespread condition of the heart. Inflammation can occur in both heart and blood vessels: myocarditis, endocarditis and pericarditis, Buerger’s disease of the arteries (thromboangiitis obliterans) and arteritis temporalis. Heart failure should also be classed as a coronary heart disease, wherever the cause may lie, as should any heart rhythm disorders which have a negative influence on the circulation of the blood.