Angina pectoris

Pain in the chest due to insufficient oxygen being carried to the heart muscle in the blood. Inadequate blood supply to the heart is usually due to coronary artery disease. Other causes include coronary artery spasm, in which the blood vessels narrow suddenly for a short time, aortic stenosis, in which the aortic valve in the heart is narrowed, and arrhythmias. If the pain of angina pectoris continues, it may be due to myocardial infarction. Rare causes include severe anaemia and polycythaemia, which thickens the blood, causing its flow through the heart muscle to slow. The pain usually starts in the centre of the chest but can spread to the throat, upper jaw, back, and arms (usually the left one) or between the shoulderblades. The pain usually comes on when the heart is working harder and requires more oxygen, for example during exercise. Angina developing during sleep or without provocation is known as unstable angina. Other symptoms may include nausea, sweating, dizziness, and breathing difficulty. Diagnostic tests usually include an ECG, which may register normal between attacks, and a cardiac stress test. Blood tests and coronary angiography may also be performed. To help control the symptoms, it is important to stop smoking and to lose weight if necessary. Attacks of angina pectoris may be prevented and treated by nitrate drugs. However, if nitrates are not effective or are causing side effects, beta-blocker drugs or calcium channel blockers may be used. Drug treatment can control the symptoms for many years. If attacks become more severe or more frequent, despite treatment, coronary artery bypass surgery or angioplasty may be necessary.